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EUROBATS Publication Series No. 5 · Guidelines for Surveillance and Monitoring of European Bats
EUROBATS Publication Series No. 5 · Guidelines for Surveillance and Monitoring of European Bats
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 EUROBATS Publication Series No. 5

Battersby, J. (comp.) (2010): Guidelines for Surveillance and Monitoring of European

Bats. EUROBATS Publication Series No. 5. UNEP / EUROBATS Secretariat, Bonn,
Germany, 95 pp.

Produced by EUROBATS, UN Environment

Coordinator Christine Boye / EUROBATS Secretariat
Editors Christine Boye,Tine Meyer-Cords
Design Karina Waedt

3rd edition 2017 - © 2010, 2014, 2017 Agreement on the Conservation of Populations of European
Bats (UNEP/EUROBATS).

This publication may be reproduced in whole or in part and in any form for educational or
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No use of this publication may be made for resale or for any other commercial purpose what-
soever without prior permission in writing from UNEP / EUROBATS.

The boundaries shown on the maps in this publication do not imply official endorsement or
acceptance by the United Nations.

Copies of this publication are available from the

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© Anne Youngman / Bat Conservation Trust
 Guidelines for Surveillance and Monitoring of European Bats

Contents
1 Foreword 9

1 Surveillance and monitoring of bats across Europe 10

1.1 The importance of surveillance and monitoring 10
1.2 International monitoring obligations 11
1.3 Surveillance and monitoring of bats at a European level 12

2 Developing surveillance and monitoring schemes 13

2.1 Introduction 13
2.2 What is being measured? 14
2.2.1 Species occurrence 14
2.2.2 Species abundance 14
2.3 Survey frequency and standardisation 14
2.4 Area coverage, stratification and sample sizes 15
2.5 Species coverage 15
2.6 Assessing the surveillance scheme − the pilot phase 15
2.6.1 Survey sensitivity and power 15
2.6.2 Survey bias 16
2.7 Data collection, management and validation 17
2.7.1 Database requirements 17
2.7.2 Database compatibility 17
2.7.3 Quality control of data 17
2.7.4 Data entry and storage 17
2.7.5 Data analysis 18
2.8 Recruiting surveyors 18
2.8.1 Volunteers or professionals? 18
2.8.2 Health and safety issues for surveyors 19
2.9 Resource issues 20

3 Surveillance methods 21
3.1 Introduction 21
3.2 Site Species Richness 21
3.2.1 Species suitability 22
3.2.2 Technical requirements 22
3.2.3 Sampling 22
3.2.4 Timing 22
3.2.5 Number of counts 23
3.2.6 Skills 23

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

3.2.7 Data management, analysis and quality control 23 3.9 Remote automatic recording 37
3.2.8 Example: The Danish bat surveillance programme 2005-2010 23 3.9.1 Sampling 37
3.3 Walked bat detector transects of foraging bats in the open countryside 24 3.9.2 Timing and number of counts 37
3.3.1 Species suitability 24 3.9.3 Data management 37
3.3.2 Sampling 24 3.10 Catching bats 37
3.3.3 Timing 25 3.10.1 Sampling 38
3.3.4 Number of counts 25 3.10.2 Example: Netting study in Germany 38
3.3.5 Data management and analysis 25 3.1 1 Ringing 39
3.3.6 Example: Bat detector surveys in Germany 26
3.12 Best practice to be adopted when carrying out bat surveys 39
3.4 Bat detector transects along roads using moving vehicles 26 3.12.1 Surveys of winter and summer bat roost sites 39
3.4.1 Species suitability 26 3.12.2 Catching bats 40
3.4.2 Sampling 26
3.4.3 Timing 26 4 Species accounts 41
3.4.4 Number of counts 27
3.4.5 Count method 27 4.1 Pteropodidae 41
3.4.6 Data management and analysis 27 4.1.1 Rousettus aegyptiacus (Geoffroy, 1810) 41
3.4.7 Example: Republic of Ireland car survey 28 4.2 Emballonuridae 42
3.5 Counts at maternity roosts 28 4.2.1 Taphozous nudiventris Cretzschmar, 1830 42
3.5.1 Species suitability 29 4.3 Rhinolophidae 42
3.5.2 Sampling 29 4.3.1 Rhinolophus blasii Peters, 1866 42
3.5.3 Timing 29 4.3.2 Rhinolophus euryale Blasius, 1853 43
3.5.4 Number of counts 30 4.3.3 Rhinolophus ferrumequinum (Schreber, 1774) 43
3.5.5 Count methods 30 4.3.4 Rhinolophus hipposideros (Bechstein, 1800) 44
3.5.6 Example: Measuring colony productivity of Rhinolophus ferrumequinum 31 4.3.5 Rhinolophus mehelyi Matschie, 1901 44
in the UK 4.4 Vespertilionidae 45
3.5.7 Data management and analysis 31 4.4.1 Barbastella barbastellus (Schreber, 1774) 45
3.5.8 Example: Estimating population size of Nyctalus noctula in housing 32 4.4.2 Barbastella darjelingensis (Hodgson, 1855) 45
estates in Hungary and other central European countries 4.4.3 Eptesicus bottae (Peters, 1869) 46
3.5.9 Colony counts in bat boxes 32 4.4.4 Eptesicus nilssonii (Keyserling & Blasius, 1839) 46
3.6 Counts at hibernation sites 33 4.4.5 Eptesicus serotinus (Schreber, 1774) 46
3.6.1 Species suitability 33 4.4.6 Hypsugo savii (Bonaparte, 1837) 47
3.6.2 Sampling 34 4.4.7 Myotis alcathoe von Helversen & Heller, 2001 47
3.6.3 Timing 34 4.4.8 Myotis aurascens Kuzyakin, 1935 48
3.6.4 Number of counts 34 4.4.9 Myotis bechsteinii (Kuhl, 1817) 48
3.6.5 Count method 34 4.4.10 Myotis blythii (Tomes, 1857) 49
3.7 Surveys of mating roost 35 4.4.1 1 Myotis brandtii (Eversmann, 1845) 49
3.7.1 Species suitability 35 4.4.12 Myotis capaccinii (Bonaparte, 1837) 50
3.7.2 Sampling 35 4.4.13 Myotis dasycneme (Boie, 1825) 50
3.7.3 Timing 35 4.4.14 Myotis daubentonii (Kuhl, 1817) 51
3.7.4 Number of counts 35 4.4.15 Myotis emarginatus (Geoffroy, 1806) 51
4.4.16 Myotis hajastanicus Argyropulo, 1939 52
3.8 Surveys at swarming sites 35 4.4.17 Myotis myotis (Borkhausen, 1797) 52
3.8.1 Species suitability 36 4.4.18 Myotis mystacinus (Kuhl, 1817) 53
3.8.2 Sampling 36 4.4.19 Myotis nattereri (Kuhl, 1817) 53
3.8.3 Timing 36 4.4.20 Myotis nipalensis (Dobson, 1871) 54

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

4.4.21 Myotis punicus Felten, 1977 54 5.4.3 Attic colony counts 79

4.4.22 Myotis schaubi Kormos, 1934 54 5.4.4 Car transect monitoring 79
4.4.23 Nyctalus lasiopterus (Schreber, 1780) 55 5.4.5 Species coverage 80
4.4.24 Nyctalus leisleri (Kuhl, 1817) 55 5.4.6 Other initiatives 80
4.4.25 Nyctalus noctula (Schreber, 1774) 56 5.5 Portugal 81
4.4.26 Otonycteris hemprichii Peters, 1859 56 5.5.1 Introduction 81
4.4.27 Pipistrellus kuhlii (Kuhl, 1817) 56 5.5.2 Surveying hibernacula 81
4.4.28 Pipistrellus nathusii (Keyserling & Blasius, 1839) 57 5.5.3 Surveying summer roosts 81
4.4.29 Pipistrellus pipistrellus (Schreber, 1774) 57
4.4.30 Pipistrellus pygmaeus (Leach, 1825) 58 5.6 Romania 82
4.4.31 Plecotus auritus (Linnaeus, 1758) 58 5.7 Slovenia 82
4.4.32 Plecotus austriacus (Fischer, 1829) 59 5.8 United Kingdom 83
4.4.33 Plecotus kolombatovici Dulic, 1980 59 5.8.1 Introduction 83
4.4.34 Plecotus macrobullaris Kuzyakin, 1965 59 5.8.2 Waterway survey 83
4.4.35 Plecotus sardus Mucedda, Kiefer, Pidinchedda & Veith, 2002 60 5.8.3 Field survey 84
4.4.36 Vespertilio murinus Linnaeus, 1758 60 5.8.4 Hibernation survey 84
4.4.37 Miniopterus schreibersii (Kuhl, 1817) 61 5.8.5 Colony counts 85
4.5 Molossidae 61 5.8.6 Survey coverage 85
4.5.1 Tadarida teniotis (Rafinesque, 1814) 61 5.8.7 The surveyors 86
4.6 Summary table of species and methods 62 5.8.8 Volunteer training 87
5.8.9 Data analysis 87
5 National bat monitoring programmes 64
6 References and further reading 88
5.1 Belgium 64
5.1.1 Introduction 64 7 List of contributors 94
5.1.2 Surveying hibernacula 64
5.1.3 Surveying summer roosts 64
5.2 France 64
5.2.1 Introduction 64
5.2.2 Long-term winter and summer surveys 65
5.2.3 Five-year surveillance programme 1999-2003 67
5.2.4 Regional surveys 67
5.2.5 Surveyors and volunteer training 68
5.2.6 Databases 68
5.2.7 Recommended surveillance methods for Miniopterus schreibersii 68
5.2.8 Recommended surveillance method for Myotis capaccinii 71
5.3 Germany 72
5.3.1 Introduction 72
5.3.2 Regional bat monitoring programmes 72
5.3.3 Surveillance of Greater mouse-eared bats 73
5.3.4 German federal surveillance and monitoring of bats under the 74
Habitats Directive
5.4 Netherlands 78
5.4.1 Introduction 78
5.4.2 Hibernacula counts 78

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

Foreword
This document provides
guidance on methods for
surveillance and monitoring
of European bat species. It
is recognised that methods
may need to be amended
to take account of regional
variations and in the light of
new information.
Some examples of moni-
toring schemes used in dif-
ferent countries are provid-
ed for illustrative purposes
only (chapter 3). These are
not intended to be repre-
sentative for every species
or every region. Distribution
maps are shown with the
species accounts (chapter
4).
Case studies of national
monitoring schemes are
also provided for illustrative
purposes only (chapter 5). It
is important to note that the
guidelines are likely to re-
quire revision and update in the future as Figure 1. Counting a cluster of 3,895 individuals of
new methods are developed and incorpo- Rhinolophus ferrumequinum / mehelyi / euryale in
Orlova Chuka cave (N Bulgaria).
rated. Updates will appear in the pdf ver-
© B. Petrov
sion of the guidelines which can be found
on the EUROBATS website. Dr. Stéphane Aulagnier, Dr. Jessamy Bat-
These guidelines were developed by tersby, Dr. Zoltán Biharí, Dr. Ferdia Mar-
an Intersessional Working Group of EURO- nell and Mr. Tony Hutson. A final edit was
BATS and other advisors listed in chap- carried out by Dr. Stéphane Aulagnier and
ter 7. The completed text was examined Mr. Tony Hutson. The distribution maps
by a small editorial group comprising were formatted by Dr . Tony Mitchell-Jones.

8 9
 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

1 Surveillance and monitoring • Assess the effects of conservation and

other types of wildlife management. There
Agreements under those Conventions, and
European Directives.

of bats across Europe

is a great deal of habitat and species man- • The Convention on the Conservation of
agement in operation and being recom- Migratory Species of Wild Animals, Bonn
mended across the European Union for Convention (UNEP / CMS) which recognises
1.1 The importance of surveillance and are needed across Europe at varying levels: conservation and sustainable use. It is ex- that endangered migratory species can be
monitoring country, region and Europe wide. tremely important to know whether such properly protected only if activities are car-
European bats are a species-rich group The information collected will assist management is achieving the intended ried out over the entire migratory range of
widely distributed through the range of ag- government and non-government organi- goals. The main ways of assessing this the species. All European bat species are
ricultural and non-agricultural landscapes sations in Europe to: are through monitoring changes in habitat listed on Appendix II. Under Article IV of
and habitats that form the wider country- • Detect changes in distribution, range and structure, species abundance and distribu- the Convention, Range States for Appendix
side. The landscape of Europe has been abundance and provide long-term popula- tion. II species are required to conclude legally
and continues to be affected by intensive tion trends in order to have an informed • Educate people about conserving and binding Agreements for their conservation.
and varied human influences that have had understanding of what is happening to Eu- managing mammal populations. Education • The Agreement on the Conservation
widespread and sometimes devastating ropean bat populations. Many bat species is an important part of any conservation or of Populations of European Bats (UNEP /
effects on bat populations. These include: travel long distances at certain times of the wildlife management initiative. Informing EUROBATS) came into force in 1994. It is
loss of roost sites through fragmentation year to maternity roost sites, mating sites the general public about issues affecting one of the Agreements under Article IV of
and loss of woodland areas, destruction or hibernation sites and in doing so often wildlife in urban environments and in the the Bonn Convention and the first interna-
and development of old buildings often cross country boundaries (FLEMING & EBY wider countryside as well as obtaining pub- tional Agreement devoted to the conser-
used by bats, and disturbance and loss of 2003, HUTTERER et al. 2005). Data collected lic support and involvement in these areas vation of bats. Out of the 48 Range States,
structures used as hibernacula or maternity in European monitoring programmes will are the keys to success. In some countries more than thirty European states are Parties
roosts; loss of foraging areas and reduction facilitate effective targeting of conservation monitoring schemes have been initiated, to the Agreement.
in insect prey through habitat destruction action (including the selection of species of using volunteers to collect the data, and in- The EUROBATS Agreement aims to pro-
and fragmentation and increased use of conservation concern, key sites and priority deed they are an extremely important part tect all European bat species, through leg-
pesticides; and poisoning by timber treat- habitats) by a wide range of organisations of many surveillance schemes. Many vol- islation, education conservation measures
ment chemicals when old buildings are ren- and individuals. unteers attend training courses to improve and international co-operation with Agree-
ovated (JEFFERIES 1972, CLARK 1981, LEEUWANGH • Influence national and international their survey and identification skills; later ment members and with those who have not
& VOÛTE 1985, RACEY & SWIFT 1986). In addi- policy / setting of conservation priorities. they receive newsletters about the results yet joined. In 1995, the First Session of the
tion, there is continued misunderstanding National governments and the European of the work they have done and thereby im- Meeting of Parties to the Agreement formed
and prejudice arising from ignorance about Community as a whole require good qual- prove their knowledge and understanding. an Action Plan, which was to be translated
bats and their lives and habits. ity information on the status and changing It is also important to inform and engage into international action. An Advisory Com-
As a result of these effects many species fortunes of different elements of biodiver- the general public more widely through mittee was established to carry forward this
are considered endangered, some have sity in order to produce effective conserva- mass participation surveys, easy-to-access Plan between the Meetings of Parties.
even become extinct in certain countries, tion and wildlife management policy. Bats websites and annual reports and newslet- The most significant items for the Advi-
and all are considered sufficiently threat- are important elements of that biodiversity ters. Surveillance and monitoring schemes sory Committee are monitoring and inter-
ened to be protected by legislation (HUTSON and the reliance of bats on insect prey and are ideal for achieving these interactions national activities. International protection
et al. 2001). The threatened status of bats in their specialised feeding behaviour and and information dissemination process. measures for bats have, above all, to con-
Europe means that information on changes habitat requirements suggest that bats are centrate on those species that migrate the
in the distribution and abundance of bat potentially valuable indicators of the gen- 1.2 International monitoring obligations furthest across Europe, in order to identify
species over time is urgently required. eral health of the environment. The threats to bats have been recognised and address possible dangers caused by
Monitoring and surveillance programmes in a number of international Conventions, conservation risks encountered along their

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

migration routes. The results of these stud-

ies are intended to lead to a comprehensive
species and habitats. Several European bat
species are listed in Annex II and all are 2 Developing surveillance and
monitoring schemes
international programme for the conserva- listed in Annex IV of the Directive, requir-
tion of the most endangered bat species in ing Member States to maintain and restore
Europe. “favourable conservation status” of the
• The Convention on the Conservation of species. Article 11 of the Directive states 2.1 Introduction
European Wildlife and Natural Habitats, that “Member States shall undertake sur- There are many factors to consider when
Bern Convention is another important inter- veillance of the conservation status of the designing long-term surveillance and / or
national treaty. It imposes a legal obligation natural habitats and species referred to in monitoring programmes. The terms “sur-
on Parties to protect all breeding and resting Article 2 with particular regard to priority veillance” and “monitoring” have been used
sites of the strictly protected species on Ap- natural habitat types and priority species.” somewhat interchangeably in the past, but
pendix II, including all European bat species Finally, a new Red List for European in fact a distinction can be drawn between
apart from Pipistrellus pipistrellus, which is mammals has been completed through the the two activities and this is quite important
listed on Appendix III. European Mammal Assessment (TEMPLE & when considering the level of information
• The Convention on Biological Diversity TERRY 2007). Monitoring mechanisms to pro- required.
(CBD) also has relevance to European bat vide data on bat populations are required Surveillance, in the context of measur-
populations. Two of the main objectives are to continue measurement of conservation ing populations, consists of repeated and
the conservation of biological diversity and status in the future. standardised observations of abundance
the sustainable use of its components. Ar- over time, using methods that enable
ticle 7 of the Convention requires that con- 1.3 Surveillance and monitoring of bats changes in numbers to be detected (HELLA-
tracting Parties should “monitor, through at a European level WELL 1991). Surveillance is a means of as- Figure 2. Three people counting on emergence.
sampling and other techniques, the com- The EUROBATS Agreement aims to assist sessing what is happening to populations © J. van der Kooij
ponents of biological diversity, paying par- in establishing pan-European surveillance of a particular species over time.
ticular attention to those requiring urgent programmes to identify population trends Monitoring requires that targets are set, iables, to monitor possible causal factors of
conservation measures and those with the and then to facilitate the timely introduction management recommendations made and changes in bat populations. Some of this
greatest potential for sustainable use.” It of measures to address any problems high- carried out, the effectiveness of the man- additional information will be particularly
notes that regard should be given to spe- lighted by the results of the programmes. agement assessed and changes made to valuable in making assessments of conser-
cies that are threatened, of social, scientific The purpose of this manual is to rec- improve the process. Monitoring therefore vation status for species listed in the An-
or cultural importance, indicator species ommend best practice in surveillance and involves surveillance, not only of the spe- nexes of the European Habitats Directive.
and alien species. monitoring methods so that consistent cies in question but, so far as possible, also An example of using surveillance data
• The European Community's Directive methods can be developed within and be- of the other factors likely to affect popula- in conjunction with other data is provided
92/43/EEC on the Conservation of Natu- tween Range States, allowing comparison tions of that species. by the UK, where research funded by the
ral and Semi-natural Habitats and of Wild of results obtained and eventually the pro- The guidelines concentrate on stand- Environment Agency (EA) and carried out
Flora and Fauna (The Habitats Directive) duction of European trends for bat popula- ardised surveillance methods required by the National Bat Monitoring Programme
was notified with the fundamental purpose tions. to produce indices of population change. (NBMP, WALSH et al. 2001 and 2003) has
of establishing a network of protected ar- It is recognised that methods may need However, it is important to note that the demonstrated a significant, positive rela-
eas (Natura 2000) throughout the Europe- to be amended to take account of regional recommended surveillance methods can tionship between foraging activity of Myo-
an Community, designed to maintain the variations and in the light of new informa- be used in conjunction with the collection tis daubentonii and insect biodiversity, it-
distribution and abundance of threatened tion. of other information, such as roost site con- self an indicator of water quality (CATTO et al.
dition, habitat extent and quality, climate, 2003). This research showed that the status
food availability, disturbance and other var- of waterway bat populations could also be

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

an important indicator of waterway “health” and to use this as an index of the true time. Creating standard survey forms with also more likely to be representative of the
and could contribute to wider conservation population is an easier and probably more clear instructions is one very effective way total population than survey sites that have
issues. reliable approach. With repeated, standard- of standardising the methods and effort been specifically chosen. This may mean
The main factors to consider when set- ised surveys, changes in the index can be used for data collection (WALSH et al. 2001 including sites in the survey sample where
ting up a surveillance programme are listed assessed over time, providing population and 2003). bats are seldom or never seen.
below. trends. If total population size has been es- Random survey requires a relatively
timated at any point in time, then the index 2.4 Area coverage, stratification and large number of sites and is particularly
2.2 What is being measured? trend can be used to reassess the popula- sample sizes useful for widespread species and those
2.2.1 Species occurrence tion estimate at regular intervals. The col- When setting up a surveillance scheme it is that are relatively easy to detect. If resourc-
There are several steps to assessing lection of standardised time-series data in important to consider the size of area to be es are available only for e.g. five or ten sites
changes in populations over time. If very this way provides an opportunity to apply surveyed and the sample size required to in a country then the monitoring sites can
little information is known about the oc- a variety of sophisticated analyses or to de- generate statistically significant trend infor- be specifically selected and counts repeat-
currence of a particular species then the velop models. mation. Generally, the finest scale at which ed at the same sites and under the same
first step is to assess the presence or dis- information is required will be the scale that conditions to reveal population trends in
tribution of the species in certain areas e.g. 2.3 Survey frequency and standardisa- determines the overall sample size. It may those locations.
habitat types, administrative units or geo- tion be that information on population trends
graphical grid squares. The methods used Surveillance schemes should collect data is required at a country level, but that it is 2.5 Species coverage
should focus on having a high probability at frequent and regular intervals. For the also desirable to have trend information for It is best, if possible, to carry out multi-
of detecting and recognising all bat species majority of purposes data should be col- regions within the country or for particular species surveillance because it is easier
occurring in a distinct area (LIMPENS & KAP- lected at least annually, because population habitat or environmental areas. The number to manage and more cost effective. Multi-
TEYN 1991, LIMPENS & ROSCHEN 1996 and 2002, trends (up or down) will be detected more of sample sites required to provide trend species bat detector surveys are possible
FLAQUER et al. 2007). quickly and with greater certainty. However, information at a country level will also be even where species echolocate at very dif-
The results of such surveys are usu- for some species less frequent surveillance required at each of the regional levels, so it ferent frequencies, especially with the use
ally displayed as simple distribution maps may be effective. is important to consider this when initially of frequency-division or time-expansion de-
showing where species are known to occur The value of surveillance data increases planning the surveillance effort. For exam- tectors. If resources are limited and only a
and can be repeated at regular (say 5 or 10 with the length of time over which they ple, a sample of 40 sites, surveyed each selected proportion of species occurring in
yearly) intervals to provide some indication have been collected. Surveillance projects year for a number of years, might be con- a particular area can be surveyed, then con-
of change in species distribution. should be long-term, i.e. for decades, which sidered sufficient to deliver country-level sideration of priorities at country, regional
will require long-term commitment. It is trends. However, if there are five regions in and European level may help in deciding
2.2.2 Species abundance only through the collection of data over the country and trends are required for each which species to include in the survey. An-
A more rigorous approach involves making long periods of time that real declines or in- of those regions, then 40 sites will need to other consideration is the ease with which
some assessment of species abundance in creases in bat populations can be detected be surveyed in each region, giving a total the species can be surveyed, because good
a given area and assessing trends in abun- separately from the natural fluctuations that of 200 sites overall. The situation becomes data on slightly lower priority species may
dance over time. This could involve carry- are often observed from year to year. more complex as additional stratifications be more informative than poor quality data
ing out a full census of all individuals and When the survey method has been se- are included. on high priority but less tractable species.
then repeating the census at regular inter- lected, it is important to ensure that the ap- Selection of survey sites should be com-
vals. However, a full census of a population plication of the method is standardised as pletely random or randomly selected within 2.6 Assessing the surveillance scheme
is likely to be time-consuming, costly and much as possible, so that it is repeatable a designed stratification, although it is pos- — the pilot phase
to have very wide confidence limits. between sites within one survey year and sible to stratify the sample at the data anal- 2.6.1 Survey sensitivity and power
Sampling a subset of the population to between years, to allow comparisons to be ysis stage. Randomly selected sites provide Establishing a long-term surveillance
provide an estimate of relative abundance made across years and over long periods of more statistically robust results and are scheme involves piloting the design of

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

the scheme to test ability to deliver the re- will be uncertainties inherent in population 2.7 Data collection, management and sets in isolation. Building a database that
quired level of information. The benchmark estimates and estimates of trend. In trend validation allows for easy information exchange, i.e. is
for monitoring sensitivity needs to be set estimation, however, repeatable counts do Managing surveillance data is probably one compatible and compliant with databases
when setting up the scheme. One measure not have to be accurate in the sense that of the most difficult and time consuming held by other organisations, will save time
used for UK birds is that sufficient sites are the population estimate is close to the ac- aspects of running a surveillance scheme. and money in the long run.
monitored to detect a population change tual population figure. If the counts are con- It is essential to have a database of survey
of 50% over 25 years, equivalent to the Red sistently wrong for any reason the changes results that can be easily accessed and ana- 2.7.3 Quality control of data
Alert declines for UK birds (WALSH et al. 2001 from year to year can still be measured lysed. If volunteers have collected the data There may be some concerns over the ac-
and 2003, GREGORY et al. 2002) and hopefully accurately using repeatable methods to then it is also important to have a database curacy of raw data provided; a process of
the more sensitive measure of 25% over 25 achieve high precision. for the volunteers, including names and ad- data validation should be put in place when
years, equivalent to the Amber Alert decline Thus the ability to count bats with the dresses, which survey they are participating entering the data electronically, so that the
for UK birds. same detectability each year remains an es- in, which site they are surveying etc. The accuracy can be checked. Generally, sur-
The power of a surveillance scheme is sential attribute of a successful bat popu- nature of the database should be decided veillance data can be collected by relatively
the ability of the scheme to correctly iden- lation monitoring scheme. However, the before commencing the project so that re- inexperienced surveyors, including volun-
tify an ongoing population trend and is ex- effects of small sources of bias are often sources, both in time and money, are used teers, because the data collection process
pressed as the percentage chance that a over-emphasised in comparison with a lack most efficiently. Some of the main issues can be fairly simple. However, it is important
particular survey design will detect a trend of precision (TOMS et al. 1999). For this rea- to consider are listed below. to have some way of verifying the data they
of the specified magnitude. Power is influ- son, it is important to measure or justifiably provide. It is also important that schemes
enced by many factors, including the mag- estimate the magnitude of bias and to take 2.7.1 Database requirements include some form of training and feedback
nitude of population change over time, be- this into consideration when balancing bias What will be the present and future re- of results to surveyors.
tween year population variation, the number and precision in monitoring schemes. quirements of the database? What infor-
of years of data, frequency of surveillance, There are a number of factors that in- mation will need to be stored and in what 2.7.4 Data entry and storage
the number of sites surveyed, proportion of fluence the encounter rate of bats on field format? The format may be determined by A decision should be taken on how to enter
samples with the species present and sam- surveys or numbers of bats counted from the type of analysis that will be carried out the data. There are several options, includ-
pling error. summer roosts. These can be divided into on the data and so these factors need to ing manual entry by the survey organiser,
The power of surveillance schemes two categories: be considered when designing the data- scanning information using Optical Mark
should be analysed in the pilot phase to as- 1. Factors that influence bat encounters base. As a minimum, the information col- Recognition (OMR), paying for professional
sess the level of information and degree of and are likely to change over time result- lected should include: species (sightings data entry or asking the volunteers to enter
certainty that a scheme can deliver. Sample ing in potentially erroneous trends; or signs), number of individuals, method the data through a website. All the methods
sizes and, therefore, the level of certainty of 2. Factors that influence bat encounters but (survey technique and bat habitat type), site have their advantages and disadvantages in
the results may vary for different species are likely to remain stable over time. and spatial reference (e.g. grid reference terms of cost, time required and accuracy.
in the same surveillance scheme (because Detailed analyses of the potential biases in at 1 km2 level or more detailed if possible), In the UK, the National Biodiversity Net-
of differences in detectability). The power the data can be conducted using a Residual date, a measure of survey effort and the re- work Trust has devoted a great deal of time
of a scheme will be increased if the design Maximum Likelihood model (REML) to ex- corder's name. and thought to all the issues to do with data
includes repeating data collection at sam- plore the effects of covariates, in order to management. All the information can be
ple sites within and across years, and this allow for the complex structure of the data. 2.7.2 Database compatibility found on their website www.nbn.org.uk.
should be a priority. Factors evaluated can include the influence It may be that exchange of data with others Data should be stored in a format that
of bat detector model, survey duration and is not a consideration. However, it is likely is accessible and can be maintained in per-
2.6.2 Survey bias temperature (BCT 2006). that pan-European information exchange petuity and made available to as wide an
Bats are difficult to count, and even using and sharing of data will have much greater audience as possible. Long-term (i.e. over
the best available sampling methods, there conservation potential than keeping data- decades) organisational, financial, data ar-

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

chiving and data supply structures should variables that are statistically significant cover a large number of sites over a short In the UK the Tracking Mammals Partner-
be put in place. In particular procedures and that have a biologically plausible re- period of time and give a level of cover- ship (TMP) and the National Biodiversity
should exist to safeguard the foregoing ir- lationship can be included in subsequent age that would be prohibitively expensive Network Trust (NBN) have produced a man-
respective of changes in personnel. GAMs. if professional surveyors were employed. ual on engaging volunteers in survey work
It is not uncommon for the first year's Volunteers also tend to be highly motivated and managing volunteer networks (TMP &
2.7.5 Data analysis results in a survey to be atypical because: and often have local knowledge of the area NBN 2004). This could provide useful infor-
The purpose of analysis is to draw correct • the methodology is not yet well estab- they are surveying and have contact with mation for organisations considering using
conclusions on population trends occur- lished (teething problems); local landowners and naturalists. Generally volunteer surveyors.
ring in species of interest. Many factors can • observers are learning the ropes; it is very cost effective to ask volunteers to
influence the appearance of trends (apart • fieldwork may start late because of the collect data rather than pay professionals to 2.8.2 Health and safety issues for
from true changes in population size) and difficulties in getting funding and recruit- do the job. This means that organisations surveyors
the magnitude of their effect should be esti- ment sorted out in time. are able to run surveys that would other- Fieldwork on bats is always accompanied
mated and methods for reducing their influ- To counteract this problem, it is best not to wise not be possible and to ensure effective by special risks for the surveyor, and all
ence put into place to reduce the possibility use the first year of a survey as the baseline use of available funds. people and institutions being involved in
of data misinterpretation. year, where the index equals 100. The first There are, however, some disadvantages a bat monitoring programme should take
The models used for analysis of species year's results can be discarded and this is to engaging volunteers. Levels of uncertain- the utmost care to minimise these risks. For
trends are usually General Additive Mod- often done in analyses once a scheme is ty increase because there is no control over this reason survey work has to be planned
els (GAM) or General Linear Models (GLM) well established. Another possibility is to whether volunteers return data or not. carefully and all appropriate measures for
with Poisson error distribution (appropriate keep the first year's data, but use the second Volunteers expect more information and safety of the surveyors should be taken. In-
for count data). Annual means can be calcu- or even the third year as the “base year” on more feedback than professionals and, be- stitutions which are involved in the coordi-
lated from survey data using GLMs, which which to base the 100 index against which cause of time constraints and level of exper- nation and implementation of surveillance
will show the variations between years. For all other estimates are shown (BCT 2007). tise, they may have more problems in carry- schemes are urged to inform surveyors
easier interpretation the means can then be If data analysis by computer is intended ing out surveys. The level of knowledge of about health and safety issues and offer ap-
converted to an Index that starts at 100 for in order to extract trends and statistic indi- some volunteers can be extremely high, but propriate education and training for them.
the first reliable year of data. ces from a series of survey results the appli- the majority of volunteers will have lower Surveys at night should be preceded by
General Additive Models (GAM) calcu- cation of the Dutch PC-programme TRIM is field craft abilities than professionals. This an inspection of the sites during daylight in
late individual trends over time for each recommended. It is available free of charge can be rectified somewhat through good order to be aware of rough or even danger-
site surveyed.They then amalgamate trends (see www.cbs.nl) and widely used by Euro- training courses.Volunteers are also likely to ous areas. If a particular place is to be occu-
from all sites to produce an overall estima- pean ornithologists from many countries as have more constraints on their time if they pied for a longer period at night, e.g. to ob-
tion of trend direction with confidence lim- well as international institutions for bird re- are giving it freely and not being paid to do serve emerging bats at a roost or to attend
its. GAMs can be used to fit a smooth line to search, e.g. European Bird Census Council the work. If volunteers are asked to survey a mist net, it should be cleared of obstacles
each dataset (TER BRAAK et al. 1994, FEWSTER et (EBCC). randomly selected poor quality sites where like branches or large stones, so the risk of
al. 2000) in order to produce a clear picture they seldom see anything, they can become being hurt or stumbling in the dark is low.
of the long-term trend for individual species. 2.8 Recruiting surveyors disillusioned with the survey work. Surveyors must have enough lights with
These smoothed curves are quite robust 2.8.1 Volunteers or professionals? Many European countries do not have a them to detect at any time during their field-
against random variation between years. When designing a monitoring scheme it is culture of using volunteers to collect natu- work all features which might be of danger,
GAM models can include covariates for important to decide whether it will be better ral history information and so do not have a e.g. ditches, burrows in the ground, wire
factors that could influence the means (e.g. to use professional surveyors or recruit vol- source of volunteer surveyors to call on. An fences, or inconvenient animals such as
bat detector make, temperature). General- unteers to collect the data. There are some alternative is to have a combination of vol- cattle or wild boar. Reserve lighting equip-
ised Linear Mixed Models (GLMMs) can be major advantages to using volunteers. A unteer and professional surveyors or only ment is recommended. Speleologist advice
used to investigate these factors, and any large network of volunteers will be able to professionals to carry out the work. should be sought when entering caves or

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

mines, and it is recommended that survey-

ors are accompanied by speleologists in
one person-night fieldwork generating one
data point. Bat detector surveys are main- 3 Surveillance methods
complex cave systems. ly restricted to the summer months and
Bats may be hosts of diseases which in most cases the three hour period post 3.1 Introduction
can also infect humans. In particular virus- sunset on each survey evening. Thus, to The surveillance methods listed here are
es (rabies and others) may be a risk for hu- generate 100 independent data points may based on those agreed at the Second Meet-
man health if bats are caught and handled require 100 nights of fieldwork and a large ing of Parties of the EUROBATS Agreement
or dust from bat faeces in a roost site is in- number of surveyors. Therefore, availability and outlined in Resolution 2.2 (Doc.EURO-
haled. When access to a bat roost or catch- of personnel and finances, accessibility of BATS.MOP2.5.AnnexBfin Resolution No. 2),
ing bats is necessary a safe approach is im- terrain, transport issues, habitat features but include other methods that have been
portant to minimise disease and accident and other aspects all have to be taken into developed in recent years. It is recognised
risks. Secure measures and special training account and their importance weighed that methods may need to be amended to
is of greatest importance if underground against the preferred survey methods. take account of regional variations and in
sites or roosts in higher trees are inspected. For example, bat detector surveys cover- the light of new information.
At any stage of their fieldwork bat survey- ing transects in the wider countryside is the The surveillance method or methods
ors must take effective measures to protect recommended method for many species, selected for a particular species or scheme
their personal health conditions. but if surveyors are in short supply or the will depend on the life-style of the bat spe-
terrain makes such surveys difficult or dan- cies concerned, local circumstances and Figure 3. Counting Miniopterus schreibersii in Huda
2.9 Resource issues gerous then another option might have to seasonal changes in bat occurrence. A luknja pri Gornjem Dolicu
ˇ cave, Slovenia.
© P. Presetnik
When setting-up a surveillance scheme the be considered. A relatively new method in- surveillance scheme should always aim to
long-term viability of the scheme is one of volving attaching ultrasonic detectors and obtain high quality data, which will be ap-
the most important factors to consider. Bat recording equipment to moving vehicles propriate for robust forms of data analyses. 3.2 Site Species Richness
fieldwork is normally labour intensive, re- is one option where fewer people may be However, the methods used should be as Measurement of Site Species Richness can
quiring highly trained surveyors with often required. simple as possible, allowing surveyors with be used whenever it is considered neces-
minimum skills and training to participate, sary to register all bat species in an area,
thus increasing the possibility of obtaining including rare or only locally occurring spe-
a sufficiently large sample over the long- cies. Some European bat species are diffi-
term. They should also cause the minimum cult to identify and often need a period of
disturbance possible to the bats, because observation to secure a safe species iden-
of the long-term, repeated nature of the ac- tification. In such cases the bat researcher
tivity. has to remain at the spot of first encounter
Surveillance of bat populations can gen- for a variable amount of time to secure a
erally be carried out in two main ways: good recording of the species, or to move
• Bat detector transects of foraging bats. around to find the species again.
This could be walked transects or Methods that are based on line transects
transects along roads using moving ve- or listening points generally do not include
hicles. prolonged stops at a given point. This
• Records of roosting bats. This could be means the occurrence of rare species is
at maternity roosts or other summer often underestimated or missed altogether
roosts, at hibernation sites and at mating and samples of rarer species will often be
roosts. insufficient for statistical analyses.

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

It is not possible to actually count numbers 3.2.3 Sampling often found during surveys with bat detec- be fully compensated for by recording the
of bats using this method. However, re- Specific geographical units are selected for tors. There are also periods between hiber- sounds and visualizing them on the compu-
peated surveys over the years, in the same survey, e.g. 10 x 10 km square grid or small nation and breeding, both in spring and ter screen. But it should not prevent those
selected areas and using a standardised administrative units. Within each area se- autumn, when bats use insect rich habitats who can from using the technique.
method will reveal changes in species oc- lect one or more main sites (known from which are restricted to small areas. It is nec-
currence and distribution and gives the ear- atlases or inventories) should be selected essary to find and protect these key habitats 3.2.7 Data management, analysis and
liest indications of disappearance as well as to have the highest possible bat species because the bats may depend on them for quality control
expansion to new sites. High species rich- richness for the region (i.e. by drawing a their survival at certain times of the year. Quantification and analysis is based on
ness can be an indicator of habitat quality polygon with coordinates on the map). If presence / absence data at a number of sites
so this method could be useful for general necessary, smaller satellite sites with sup- 3.2.5 Number of counts in each surveyed region. Sound recordings
monitoring of the environment. plementary biotopes are included to ensure Surveys can be repeated at regular inter- must be stored and made available. Subse-
registration of bat species missed in the vals, i.e. every six years (to coincide with quent control is sometimes useful for veri-
3.2.1 Species suitability main site(s). Main sites are usually between frequency of Habitats Directive reporting). fication when dealing with species records
Potentially all European species can be de- 1-10 hectares depending on diversity and Repeated survey in each of the selected in new areas and in difficult identification
tected using this method, particularly where configuration of biotopes. Satellite sites are areas reveals changes in presence or ab- cases.
there is relatively low species richness. often smaller. sence of species. The number of encoun-
Sites are surveyed on foot, with detec- ters or number of bats hunting together or 3.2.8 Example: The Danish bat surveil-
3.2.2 Technical requirements tors, under optimal weather conditions, swarming can give a rough estimate of bat lance programme 2005-2010
The method requires the use of high quality during “prime time”, i.e. the first four hours abundance. This surveillance method has been com-
bat detectors (heterodyne combined with after sunset. The different habitats and lo- monly used with great success for many
time expansion or high speed recording) calities within the site are visited several 3.2.6 Skills years in Sweden and Denmark (AHLÉN &
and good quality recordings of long se- times during this period to cover differ- Bat detector researchers need high quality BAAGØE 1999). The current programme has
quences of bat calls. For some species vis- ences between species in time of emer- training to attain the capability necessary been running for four years. Main sites and
ual clues about behaviour and appearance gence, commuting and foraging. This may for finding all species and for recording and satellite sites in 26 selected 10 km UTM
are also needed, sometimes with a strong include visits inside large barns or other analysing bat sounds. Those with a good squares are surveyed each year during the
handheld lamp (AHLÉN & BAAGØE 1999). In buildings (e.g. for Plecotus). Satellite sites ear quickly learn to distinguish the easy bat
some cases field work also involves the use can be visited later the same night, but still species by sound, and over time they can
of other methods such as searches inside within the “prime time”. build up great skill in distinguishing also
buildings or other structures, netting and ARDs can be used especially in areas small differences in sound quality, rhythm
automatic registration. with high species richness, or in one or and frequency. Most people have initial dif-
Automatic Recording Devices (ARDs) or more of the satellite sites. If any species re- ficulties and need a couple of seasons of in-
“autoboxes“ can also be used. These act as main unidentified, the same site, or a satel- tensive field experience to build up enough
a complement to detectors, especially in lite site, is visited the following night, using skill to be able to work professionally with
species rich sites. The boxes collect time- netting or other supplementary activities. detector-based surveys or monitoring.
expansion or high speed recordings of high Individual human beings have quite dif-
technical quality and most species can be 3.2.4 Timing ferent abilities to learn to use sound, and
identified. The efficiency of finding all spe- Most often surveys are carried out during there is no doubt that some people will
cies is likely to be improved by adding this one night in the breeding season in the first never learn to use this technique, in spite of
Figure 4. “Standard Bat”- All Danish 10 km UTM
method. Instructions should be given on four hours after sunset, when females re- great effort, especially if their sound mem- squares visited at least one night with high quality
the best positions for the boxes and appro- main in an area and generally forage short ory is not good enough. This is a problem, bat detectors under optimal conditions in 1981-
priate use of netting or visual observations. distances from maternity roosts. Roosts are especially since this lack of “ear“ cannot 2004 (provided by H. Baagøe).

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

areas if at all possible. Sampling should The number of counts that should be car-
cover a wide range of habitat types (these ried out during the active season will de-
may be the strata) rather than just selecting pend on resources available. Generally, the
the habitats most likely to contain bats. For more counts that are completed at each
a survey of waterways, data are collected sampling point the lower the associated
in a simple, repeatable fashion at a random sampling variation. However, it is statisti-
selection of water bodies. cally preferable to sample more areas (use
Suitable sampling may be based on more replicates) than to sample areas more
selecting squares from the national map- intensively (repeated measures at fewer
ping system (non-stratified) or selecting sites). Two to three counts per area is prob-
areas from a national land-classification ably a good number, but if bat activity in a
scheme (stratified). Within these areas, certain area has to be evaluated carefully,
Figure 5. Based on knowledge about bat species Figure 6. Polygon showing one of the surveillance
occurrence in each of the squares in Figure 1, 157 sites in one of the selected squares (provided by
line-transects, point-counts or a combi- up to five surveys per year could be made.
squares of special interest were selected (red H. Baagøe; map source: the National Survey and nation of both can then be set up accord- For surveying waterways, surveyors
squares). In these squares main sites and some- Cadastre, Denmark). ing to a standard methodology. Suitable should mark out ten points, approximately
times satellite sites were selected for surveillance line-transects may involve a walk across 100 m apart, along a 1 km stretch. On two
for bat species richness (provided by H. Baagøe).
as rivers and lakes; the standard field sur- or around the square, or a random 1 km evenings during the survey months, survey-
Red rasters: satellite sites in neighbouring squares.
vey methods can be adapted for use at stretch of water body (WALSH & HARRIS 1996a ors should stand at each of the ten points
Blue rasters: surveillance in well known winter
roosts.
waterways to collect data on population and 1996b, MASING et al. 2004). for four minutes, recording bat activity with
trends for those species. a heterodyne detector. A torch should be
breeding season (Figures 4, 5, 6). Results Remote automatic recording of bats can 3.3.3 Timing used to confirm the bat is flying close to the
are entered into a database. replace surveyors in certain circumstances Sampling effort should be well-defined, water surface, a behavioural characteristic
to record bat presence in a particular habi- either by setting the length of transect to of Myotis daubentonii (dry ultrasounds with
3.3 Walked bat detector transects for tat. be followed (at a constant speed) or by maximum at 45 kHz, flight 5-15 cm above
foraging bats pre-defining the time to be spent at each water surface) and Myotis dasycneme (dry
Ultrasonic-detector surveys using pre- 3.3.1 Species suitability sampling point. Similarly, the time of day or wet ultrasounds at 60-25 kHz with maxi-
defined sampling methods provide the Counts away from roosts using bat detec- when sampling is to be carried out should mum at 35 kHz, flight 15-60 cm above water
most statistically-robust and repeatable tors are most suitable for any species which be standardised. Sampling should com- surface). If it is difficult to estimate height
surveillance, although they provide an in- has a loud and distinctive echolocation call. mence at a given time related to sunset then flying speed can be used. See species
dex of abundance rather than absolute den- At water bodies the method is most suit- and continue for at least one hour and up to account for how this method might also ap-
sity. Standardisation of bat detector surveys able for Myotis daubentonii and Myotis three hours. The timing of survey of a given ply to M. capaccinii.
is possible using line-transects and point- dasycneme. The method can also be ap- transect will depend on whether early or
counts. Line-transect surveys require the plied to Myotis capaccinii in areas where late flying species are being detected. 3.3.5 Data management and analysis
observer to follow a pre-determined path of M. daubentonii and M. capaccinii are not Surveying waterways should be carried All separate bat passes (a “bat pass” can be
known length; point-counts require the ob- sympatric. out during the months of peak bat activity defined as a sequence of two or more echo-
server to listen at a fixed point for a known (May-August). location calls registered as a bat passes
time. The two methods can be combined 3.3.2 Sampling within the range of a microphone (FENTON
to give estimates of relative abundance of Sampling areas may be chosen in a variety 3.3.4 Number of counts 1988 and 2001, WALSH & HARRIS 1996) should
species being surveyed. of ways, provided these do not violate the Surveyors should make a day visit to each be recorded on a map (for transects) or as-
Some bat species forage preferentially need for a repeatable sampling method and site to secure landowner permission and to sociated with a sampling point (for point-
or even exclusively over water bodies such a random, or stratified-random, selection of assess the site for safety and familiarisation. counts). For analysis, the classification of

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

habitat along a transect or around each Annual vehicle-based surveillance should does not have to coincide with the highest this reason vehicles should be driven at a
point should be completed during a day- have high year to year precision, provided period of activity. The annual survey date, constant slow speed where possible (no
time visit. the following factors are recorded: 1) start start time and starting point should be con- more than 25 km / h).
time; 2) survey date; 3) route taken; 4) road- sistent between years and repeat surveys
3.3.6 Example: Bat detector surveys in side habitats noted; 5) same bat detector should take place under similar environ- 3.4.6 Data management and analysis
Germany system is used. Roads are easy features mental conditions. The main advantage of the vehicle-based
In Germany a proposal was made for stand- to follow and normally well identified on survey is that few surveyors are required to
ardising bat detector surveys in order to maps. 3.4.4 Number of counts deliver a large number of sites. For exam-
fulfil the EC Habitats Directive reporting Surveyors drive each route, with each sur- ple, based on power analysis, a single sur-
requirements (DIETZ & SIMON 2005). Recom- 3.4.1 Species suitability vey transect driven no faster than 25 km/h. veyor could collect sufficient data with ten
mendations were as follows: This method is generally restricted to open / The route should be driven (preferably nights of fieldwork to provide a statistically
• In each survey area at least one line- edge species such as Pipistrellus spp., Nyc- twice) annually within a four-week period. defensible surveillance project.
transect should be allocated per 500 ha. talus spp., Eptesicus spp. and Vespertilio More transects can be driven if resources Roadside habitats are unlikely to be in
Line-transects should include several murinus as they are loud echolocators that allow, to increase survey sensitivity. As proportion to habitats available in the wider
habitat types. are found foraging in open habitats along surveillance is likely to be long-term, costs countryside and this introduces biased hab-
• Each line-transect should be 1.5 to 2 km roadsides. Miniopterus schreibersii might should be minimised. itat sampling. There is potential for street-
long with surveyors taking about 8 min- be suitable, because although it forages in lights to attract certain species and give an
utes to walk each 100 m section. closed habitats, or high in the air, it is also 3.4.5 Count method over-estimate of species abundance along
• Line-transects should be surveyed five found at street lamps, but not where it is Surveyors can design a route within each roads in relation to actual abundance in the
times per year, between the end of April sympatric with Pipistrellus pygmaeus. 30 km block that is roughly circular and of wider countryside. There is also potential
and mid-September. All surveys should approximately 100 km length, which can be for roads to be developed at a different rate
be carried out under good weather con- 3.4.2 Sampling driven within a four-hour period. and in a different way to the general coun-
ditions. The protocol should be designed to mini- The route can be divided into transects tryside, introducing other biases in data
• If particular species need to be recorded mise variation between repeat visits. Any of e.g. 1.6 km length, 3.2 km apart. Each collection. It is important therefore to note
(e.g. Myotis myotis) additional 100 m detector system could be used, but once transect can then be defined as an inde- bat encounter rates at streetlights and any
line-transects could be selected in the a system has been selected then the same pendent sampling unit. Thus for each route changes in type and number of lights over
most promising habitats. These specific system should be used on each survey. driven, 20 independent sampling units are time, and any road development activity.
transects should be surveyed five times Survey transects should be representa- surveyed, providing a large sample size With these biases in mind, great care
per year, taking 15 minutes to walk the tive of landscape types (not forgetting from a few nights of survey. The distance must be exercised if attempting to extrapo-
transect. the inherent bias in following roads). The between each survey transect, combined late bat encounter rates from vehicle-based
landscape to be surveyed can be divided with the driving speed, makes it highly un- surveys to the wider countryside, because
3.4 Bat detector transects along roads into 30 km blocks and a selection of these likely that the same bat could be recorded they could lead to erroneous conclusions.
using moving vehicles blocks chosen at random. This provides a on more than one survey transect. If this is to be attempted then, at the very
At a minimum, vehicle-based projects de- structure and target number of blocks to be Adding stopping points or sections least, roadside habitat assessments should
liver high quality distributional data for surveyed. alongside rivers, canals or at other water be made. For example, preliminary results
common species and will identify distri- bodies means that Myotis cappacinii, from vehicle-based surveys in the UK sug-
butional changes in common species with 3.4.3 Timing M. daubentonii and M. dasycneme could gest that pipistrelle bats are more likely to
good sensitivity. Through annual monitor- Ideally surveillance should coincide with also be detected using this method. be encountered along roads with bound-
ing, they will also provide statistically ro- the pre-parturition period (April to June Driving speed alters recorded peak fre- ary features than featureless roads (see
bust conclusions on population trends of depending on latitude) to avoid annual quencies due to Doppler Shift and this can also VERBOOM 1998). Thus we assume that
common species along roadsides. “noise” from numbers of volant young and result in misidentification of species. For the vehicle-based survey is monitoring pipi-

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

Table 1. Results of the Republic of Ireland Car Survey power analysis. veyors to survey multiple sites in a day and serotinus and Barbastella barbastellus (SI-
The table shows the number of years required to detect Amber and Red Alert in relation to the number of fewer surveyors are required than on field MON et al. 2004). However, in the case of Ep-
squares surveyed.
projects to collect the same data quantity. tesicus certain sites are suitable for internal
Pipistrellus pipistrellus Pipistrellus pygmaeus Nyctalus leisleri Non-invasive counting for small colonies counts (several cases in Slovenia and Ser-
Squares can also been performed using DNA analy- bia).
Amber Red Amber Red Amber Red
ses of bat droppings using specific mark- Species such as M. myotis and M. dasyc-
10 > 25 11 > 25 11 > 25 12
ers (PUECHMAILLE & PETIT 2007, PUECHMAILLE et neme, and to some extent Rhinolophus
15 19 10 24 10 > 25 11 al. 2007). Small samples of droppings col- spp., also use networks of sites in some
20 16 9 20 9 24 10 lected from beneath the maternity colony regions, and the numbers in the central
25 15 7 17 8 19 9 at known intervals (weekly, fortnightly or roost might fluctuate. However, these spe-
monthly) may be dried and stored in small, cies have a tendency toward the model of
labelled canisters. If surveillance highlights a “central important roost’’ with “satellites’’,
strelle bats at boundary features (not the as a way of monitoring the status of a spe- population declines, samples can be ana- so this surveillance method is considered
roads themselves) and if further research cies. lysed for diet content and contaminants. appropriate.
confirms this, then encounter rates of bats External counts of bats emerging from
along roads with boundaries can be extra- roosts are preferred to counts inside roosts 3.5.1 Species suitability 3.5.2 Sampling
polated to include boundary features away to minimise disturbance, but may not al- The most suitable species for colony counts In countries or regions where the species
from roads. ways be possible. In some cases it is better are those where: is widespread, a sample of sites should be
to carry out counts inside the roost, usually • The bats appear to be relatively faithful counted on a regular basis, with roosts se-
3.4.7 Example: Republic of Ireland Car when colonies are very large, or where bats to their maternity roosts, and return pre- lected to give a range of roost sizes (number
Survey roost in mixed species groups and identifi- dictably to the same site each year; of bats), geographic locations and land use
A pilot survey using this method was car- cation with a bat detector on emergence is • The establishment of a new colony is a types. Stratified random sampling of roosts,
ried out in the Republic of Ireland in 2004 very difficult. rare event; with strata selected for roost size and / or
(ROCHE et al. 2005). Table 1 shows the results Internal counting is the method most • The species tends to form large colo- land use type probably provides the most
of power analyses, indicating the number of widely used in central and eastern Europe nies; statistically robust methodology. Where the
years of surveying required to achieve 90% where buildings, such as churches and • The bats can easily be distinguished from species is rare, it may be possible to count
power to detect Amber Alert (25% decline castles, have very large attic spaces, al- other species which may be present. all known sites.
in 25 years) and Red Alert (50% decline over lowing surveyors to go in and survey with- Examples of such species include Rhinolo-
25 years) for each species. All results using out disturbing the bats. Colonies are usu- phus euryale, R. ferrumequinum, R. hippo- 3.5.3 Timing
two repeat surveys of each square per year ally highly philopatric and faithful to their sideros, R. mehelyi, Myotis blythii, M. ca- Counts need to be timed to take account of
(each square with 20 transects of 1.6 km). roosts throughout the breeding season. In paccinii, M. dasycneme, M. emarginatus, the breeding season, which will vary with
southern countries and in central Europe, M. myotis, M. nattereri, Miniopterus schrei- climate. Local research may be required to
3.5 Counts at maternity roosts maternity colonies of some species such bersii, Plecotus spp. determine this before setting up a moni-
Counts of bats at maternity roosts are a tra- as M. schreibersii, R. euryale, M. myotis Colony counts are less appropriate for toring project. Counts should generally be
ditional method for monitoring the status of and M. capaccinii are often found in mixed species that often use a network of roosts timed to occur between the time when bats
roosts. Information can be used to make an groups in warmer mines and caves through- and where individuals frequently change arrive in the maternity roost and the time
assessment of the importance of the roost out the summer and internal counts are re- between roosts. Internal counts are also that the earliest births occur, usually be-
at local, regional, national and internation- quired to estimate numbers of the separate generally not appropriate for crevice dwell- tween late April and mid July depending on
al levels through collation and analysis of species. One advantage of internal counts ing species, where only a proportion of the latitude. This will give an indication of the
data. Counts of bats in, or emerging from, is that multiple species can be encountered bats may be seen at any time. Such species number of adult females in the population
maternity roosts have also often been used at the same site. It is also possible for sur- include Pipistrellus pipistrellus, Eptesicus associated with the maternity site.

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

3.5.4 Number of counts bad weather, as this is known to inhibit bats mising the time spent with the colony and, colony may be possible in some circum-
At least one count should be carried out an- from emerging. Bad weather conditions therefore, minimising disturbance, which stances with some species. For some cave-
nually, covering the period between the ar- include low temperature, rain or strong is especially important for some shy (sen- dwelling bats and species that preferentially
rival of bats and the first possible date for winds. sitive) species such as R. ferrumequinum roost in buildings it may be possible to enter
parturition. The preferred method involves • In some cases, for instance when colo- and R. hipposideros. The least invasive the roost after the adult evening emergence
two counts during this period, but the lo- nies are very large but it is not possible to methods involve the use of infrared cam- and to count the non-volant young. In cases
gistics and cost of organising counts may do internal counts (see below), filming of era techniques used in combination with a where the adults remain with the young af-
mean that only one is possible. If data on bats emerging from the roosts using infra- reflector with IR filter. For large colonies a ter the young are able to fly, such as some
reproductive success are required, another red videos connected to bat detectors is de- stick of known length can be used to cali- Myotis species, a recorded increase in the
count should be carried out prior to colony sirable. Several caves in southern Europe brate the subsequent estimation of surface colony size post-weaning may indicate
dispersal. Statistical advice suggests that have very large colonies of bats that cannot area covered by individuals. the number of young weaned. However, in
it is better to increase the sample of roosts be counted using internal counts due to dif- • This type of count should be carried out some species such as Eptesicus serotinus
than to increase the number of counts at ficulties in accessing all parts of the cave, by two people, one taking photographs, the and Pipistrellus pipistrellus, the adult fe-
each roost. However, it is also important large mixed clusters of bats or the height of other holding the light, and should be com- males depart as soon as the young are ca-
that the agreed number of counts is carried the roosting places. In such caves several pleted as quickly as possible. It is best to pable of feeding themselves and the spread
out at each roost and that the same time pe- evenings are necessary to determine the take photos of separate groups of bats, but of weaning dates means that there may be
riod is used each year. emergence time and behaviour of different if groups are too large, then 2-3 photos of no marked increase in the colony size, or
species and to assess species richness and a group can be taken, shifting the focus of any such increase may not reflect the full
3.5.5 Count methods numbers. the camera each time. One of the main limi- productivity of the colony.
Counts of emerging bats • Another method in cases of very large tations of this method is the distance from
• Observers should ensure that all entrances colonies (> 5,000 ind.) where thousands counter to colony. 3.5.6 Example: Measuring colony produc-
to the roost are known and be stationed out- of bats emerge within a few minutes can • One or two counts during the season tivity of Rhinolophus ferrumequi-
side each entrance, but not so close as to be to count or assess, respectively, emerg- should be sufficient. Surveyors should num in the UK
disturb the bats or obstruct their flight lines. ing bats over a period of one minute and have some knowledge of identifying spe- To measure the productivity of R. ferrum-
The number of bats emerging in each five to repeat this one-minute-count every five cies and all crevices and timbers should be equinum colonies three annual counts can
minute period should be recorded. minutes. The number of bats for the five- checked using a torch. Droppings located be done:
• Recording should begin when the first minutes-period then can be calculated by underneath timbers are a good indication 1. Emergence count of females in the sec-
bat emerges and end when it is too dark to extrapolation of the numbers of the one- of presence. ond or third week of June (A = number of
continue counting, or no bat has emerged minute-counts, taking the middle of two • Bats are less disturbed by red light; a red females);
for ten minutes. consecutive one-minute-counts per minute filter can be applied to the torches. Counts 2. Emergence count of females in the first
• The roost entrances should not be illumi- (RUDOLPH et al. 2005). However, in such cases should be carried out in the morning and two weeks of July with a count in the col-
nated with white light. It is recommended it is necessary to observe the roost and the early afternoon because bats start to fly ony when females have left (control of A;
that no torch is used, though one fitted with bats behaviour in two consecutive nights around in mid-afternoon. Strong torches B = number of juveniles);
a dark-red filter may be acceptable (DOWNS and to conduct the monitoring with two ob- are needed for high ceilings. 3. Emergence count in the last week of July
et al. 2003). servers. • Counts can be carried out in any kind of or first week of August (control of A and
• Ultrasonic detectors can be used to give weather conditions, but colonies are less B; C = number of dead juveniles in the
warning of the approach of a bat. They Counts inside the roost active and easier to count when tempera- colony) (RANSOME 1998).
should be tuned to an appropriate frequen- • In regions where mixed species groups tures are cooler.
cy and used with headphones. occur, a photographic method of counting 3.5.7 Data management and analysis
• Counts should not be made in bad weath- bats inside the roost may be appropriate. Measuring colony productivity Counting roosting or swarming bats usu-
er conditions, or on nights with previous The main advantage of this method is mini- Measuring the productivity of a maternity ally involves non-random selection of sur-

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

vey sites. The sites tend to be ones that are then on the other side of the houses, listen- occupancy can be considered as a surveil- on field projects to collect the same data
known about, often because they are visible ing for the sound of bats. The aim is to lo- lance strategy. quantity.
sites with large numbers of bats. If the sam- cate the position of bat roosts and mark the Counts in bat boxes may, however, be One problem with hibernation site surveys
ple size of roosts is sufficiently large then location on a map. the only suitable method for some wood- is that the relationship between the number
any biases in the dataset introduced as a re- land species whose natural roosts are sel- of bats seen and the number of bats present
sult of being non-random are probably not dom found and which often use a roost is not always clear. In complex sites bats can
important, but it is a factor to consider. o o o o o o o network (for example Myotis bechsteinii, hide away in cracks and crevices and it is not
Colony counts are not the most statis- M. daubentonii and M. nattereri, Barbastella always possible for surveyors to see all of
tically robust method for assessing popu- houses barbastellus, Plecotus auritus). Furthermore, them. As an example: Bad Segeberg cave in
lation trends, because of the non-random Figure 7. Scheme of walked transects along houses. these species often live in locations where northern Germany is a cave with lots of fis-
sampling method. However, for some spe- species cannot easily be surveyed using sures. About 300 individual bats are visible
cies that predominantly dwell in buildings other methods, or where species seldom upon normal visual inspection. About 15,000
and are highly philopatric, it is a robust Two counts are carried out at least sev- use buildings as roosts. In these cases the (mostly M. nattereri and M. daubentonii) are
method for assessing population trends if en days apart, the first count between sampling unit is the area of woodland and present when counted with infrared detec-
the majority of potential buildings are sur- 1-15 September, and the second count be- not the individual bat-box. Bat boxes are es- tion (KUGELSCHAFTER et al. 1995). For complex
veyed. tween 16-30 September. Counts are car- pecially useful in artificial (mainly non-native sites like this an assumption for population
The relationship between trends in spe- ried out on calm, clear days with no rain, coniferous) forests where natural roosts are trend analysis is that the proportion of bats
cies' colony size and population trends has starting half an hour before sunset. The lacking or rare. In such forests real popula- seen to the number of bats actually present
not been established, but comparison of number of colonies along a transect and tion trends can be measured (e.g. SCHMIDT remains constant over time.
different survey methods over time may the number of buildings on each housing 2000, BLOHM 2003, HEISE & BLOHM 2003; see In roost sites with large spaces species
help to provide the required information. estate are counted to provide an estimate also overview in MESCHEDE & HELLER 2000). identification can be problematic because
of the number of colonies in a town. In semi-natural forests this method can at of poor visibility or low light and because
3.5.8 Example: Estimating numbers of least contribute to determining the occur- the bats could be a long distance away from
colonies of Nyctalus noctula within 3.5.9 Colony counts in bat boxes ring species spectrum and status of bats. the surveyor. In such cases the reliability of
a roost network in Hungary and Counts of colonies using bat boxes has collected data must be evaluated in order
other central European countries been suggested as a surveillance method. 3.6 Counts at hibernation sites to avoid biases.
In Hungary, Nyctalus noctula is a very com- However, bat boxes only occasionally hold Some bat species aggregate at hibernation Bats are vulnerable to disturbance when
mon species in the housing estates of large an entire colony and counts are unlikely to sites during the winter months and it is pos- hibernating and strict protocols should be
towns, where it roosts in the crevices of pre- be representative of the general popula- sible to make annual counts of the number observed before and during hibernation
fabricated panels of tall ten-storey houses tion or to produce a comparative national of bats encountered. Hibernation counts are site surveys. Some species can be hard to
(BIHARI 2004). N. noctula is very active before or even regional picture, because breed- particularly useful in assessing the impor- identify unless they are handled, but han-
sunset, and can be heard squeaking very ing success in boxes is likely to be differ- tance of a site for conservation purposes; dling is not recommended as it is consid-
loudly. The monitoring method described ent from natural sites. There are additional site data collected by monitoring pro- ered too disturbing and could affect the
below has been used in 19 towns and 3 issues of potential disruption to bat com- grammes can be used to inform decisions survival of the bat.
housing estates in Budapest to estimate munities through placing large numbers when considering site protection under na-
population size for the species. of bat boxes in semi-natural woodland and tional and international designations. 3.6.1 Species suitability
disturbance to bats because boxes might One advantage of hibernation site moni- Counts of bats in hibernation sites are most
Method: need to be invasively checked for occupan- toring is that multiple species can be en- suitable for species where:
In the housing estates a transect is chosen cy and numbers. Therefore, the effect of in- countered at the same site. It is also possi- • The species is faithful to the site;
which passes 40 houses. Surveyors walk troducing bat boxes to woodlands needs to ble for surveyors to survey multiple sites in • The species can be identified accurately
the transect twice, first along one side and be thoroughly investigated before bat box a day and fewer surveyors are required than without disturbance;

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• The species hibernates in large numbers ence between the number of hibernating is changed, any differences should be re- However, one could also use the adver-
at one site; barbastelle and Natterer's bats and the tem- corded. Ideally, the extension of counting tisement calls of the species and take the
• A high proportion of the population regu- peratures the days before a count has been to new parts of a site should be recorded number of advertising males as the param-
larly hibernates underground. observed, leading to low numbers of these separately. Data should be recorded sepa- eter for monitoring. The whole area can be
bats in hibernacula if the temperatures are rately for each site, or each sub-site, particu- surveyed and a cluster analysis performed,
3.6.2 Sampling several (5-10) degrees above 0° C and to larly if parts of the site are liable to flooding or transect and relative numbers from year
In countries or regions where the species much higher numbers if temperatures are or other climatic factors that may make it to year can be used.
is widespread, a sample of underground just around or below zero (e.g. MESCHEDE & impossible to count all parts of the site each
sites should be counted on a regular ba- RUDOLPH 2004). Therefore, cold weather con- year. 3.7.3 Timing
sis, with sites selected to give a range of ditions should be preferred within the time The best time to survey mating roosts is
sizes (number of bats), geographic condi- period of winter counts. 3.7 Surveys of mating roosts during peak migration in the region, and
tions and land-use types. Stratified-random Tree roosts, including bat boxes, are often this will vary across Europe. For e.g. Nyc-
sampling, with strata selected for roost size 3.6.4 Number of counts occupied by advertising males displaying talus noctula and Pipistrellus nathusii the
and/or land-use type probably provides The logistics and cost of organising counts territorial behaviour. Such roosts can be peak in advertisement behaviour seems to
the most statistically-robust methodology, and the danger of disturbance to bats found by following the advertising calls, coincide with the peak in migrating females
though the accessibility of sites is likely to means that the number of counts at each which can be heard without technical aid in passing by.
influence the sampling methods. Where the site should be limited to a maximum of two some species. It is most efficient to survey In the region of Bonn, Germany, some
species is rare, it may be possible to count per winter (preferably one count), carried along edges of forests and water, especially bat boxes are occupied by P. nathusii from
all known sites. out at least two weeks apart. To reduce dis- near larger rivers and lakes, because such August to September and then by N. noc-
Areas where only small numbers of in- turbance to a minimum and following sta- places are preferred by males of some spe- tula throughout the winter.
dividuals are found, spread across many tistical advice, it is better to organise counts cies.
sites, present great difficulties for hiberna- at more sites than to increase the number 3.7.4 Number of counts
tion site monitoring and it is probably bet- of counts at each site. However, it is also im- 3.7.1 Species suitability During migration the number of females in
ter to attempt to find maternity sites. portant that the agreed number of counts is This method is most suitable for species the mating roost of a territorial male changes
carried out at each roost and that the same where the males display territorial mating from day to day. For this reason roost sur-
3.6.3 Timing time period is used each year. behaviour and generally have loud dis- veys should be carried out every week until
The extent to which bats occupy hiberna- play behaviour, notably Nyctalus noctula, there are no longer any bats present.
tion sites depends on the local climate; in 3.6.5 Count method N. leisleri and Pipistrellus nathusii (in trees
some parts of Europe bats may be active When large numbers are present, it may be and houses), but also Myotis dasycneme 3.8 Surveys at swarming sites
throughout most of the year. This makes better to estimate the area the bats cover (found in mating roosts, but without loud In late summer and autumn some species
the method more reliable in the northern through the use of photography or video display behaviour). P. pygmaeus and P. pipi- begin to migrate to sites where mating
part of species' ranges, where the bats camera. Strong torches are needed for strellus do not advertise from a stationary and / or hibernation take place. During this
will remain in hibernation sites for longer high ceilings. In some cases binoculars are site but in a territory. As with breeding birds period, large numbers of bats can be en-
periods. Counts are probably best done very helpful. Notes should be kept annually this behaviour can be used to assess terri- countered at some sites, swarming inside
in January or February, but local research for each site indicating which areas were tories and numbers of advertising males. and outside the site. This is primarily a mat-
may be required to check this before setting searched and the main areas in which bats ing event, since it occurs long before hiber-
up a monitoring project. were found. This provides useful informa- 3.7.2 Sampling nation, but probably also serves to check
The weather conditions can influence tion for future surveyors. Surveys of mating roosts in tree holes or bat hibernation sites and guide inexperienced
the hibernation behaviour of bat species It is preferable to adopt the same count- boxes follow the same procedures as sur- juveniles to them.
that are tolerant of low temperatures: in ing method each year, so that valid com- veys of maternity colonies at such places, Swarming sites attract very large popu-
Germany, for example, a strong depend- parisons can be drawn. If the count method counting the number of emerging bats. lations of bats (thousands) from large catch-

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

ment areas (~ 100 km radius or more), with minute for a period of at least a week, ide- of other species peaks between mid-August edges, to monitor the use of flightpaths by
many hundreds visiting a site each night at ally several, in early September. Although and mid-September, but can continue until a species.
the peak of the season. The number of spe- species identification would be difficult or mid-October (e.g. M. nattereri, see MESCHEDE
cies present varies from five in the north impossible, it would give an index of the & RUDOLPH 2004). In the UK, swarming ac- 3.9.2 Timing and number of counts
of England to ten or more in other parts bats visiting the site to mate (and perhaps tivity peaks between mid-August and mid- The device has to be used in accordance
of Europe. Two hundred or more individu- later hibernate) from the large catchment. It September. Peak activity is 4-5 hours after with the needed monitoring data. Surveys
als may be caught per night at the “best” could be repeated with ease each year. sunset but again may vary across Europe. for wind turbine installations should start
sites, representing an estimated 5-20% It should be noted that species composi- early in the season, shortly after hibernation,
of the bats present each night. Individual tion can vary considerably through August 3.9 Remote automatic recording to identify possible migration routes e.g. of
bats are faithful to one or a small number and September, so some initial investigation This method can be used to record bats Nyctalus noctula through an area. Surveys
of sites. Every late summer / autumn a very is needed to determine patterns of activity where it is not possible to use surveyors. at cave entrances to monitor post-hiberna-
high proportion of these bats will visit their of different species. Harp-trapping / mist- Recent developments in technology allow tion activities should be done at least twice
swarming site(s) on one or more occasions. netting can be used to determine the spe- a range of bat species to be recorded and during the six-week early spring period e.g.
Surveillance of swarming sites can there- cies present and their relative abundance. their calls identified with sonogram analy- after the last nights of severe frost.
fore provide a useful index of the status of Following the initial assessment of species sis. Remote automatic recording can be Recordings during the main bat activity
a number of species over a very large area. numbers, catching bats at intervals can be carried out using a heterodyne detector period should include at least two settings
Swarming populations are dominated used to keep track of species present and connected to a device that allows record- of the recording device, with the detec-
by males (60-90%), but it is not known if this their relative abundance. ing of full spectra or time-expanded calls. tor placed at the same spot each time and
is a real sex bias or an artifact of differences Because of the often large numbers of The method is generally restricted to single tuned to the same frequency.
in behaviour that make them easier to catch bats, harp traps are preferred to mist nets species surveys e.g. surveying M. dauben-
(KERTH et al. 2003, RIVERS et al. 2006). and should be used whenever possible. The tonii over a water body or at potential sites 3.9.3 Data management
number of traps and / or nets used will de- for wind turbine construction. All separate bat passes have to be identi-
3.8.1 Species suitability pend on the size and number of entrances fied clearly. Care should be taken to identify
The method is suited for those species to the site. However, the numbers and po- 3.9.1 Sampling other bat species using similar echolocation
that appear to use a mating strategy that sitions should be identical each year. Traps Sampling can be done at different sites frequencies to the chosen one. Misidentifi-
involves extensive chasing flights in large and nets should not prevent bats from en- and for different purposes. Placed at the cation could occur due to the skewed tonal
bat assemblages (hence the term swarm- tering or leaving the site, to minimise dis- entrance of roosts e.g. of caves, it can give quality of the registered calls.
ing), these include Myotis bechsteinii, turbance. an indication of the onset of activities either
M. brandtii, M. dasycneme, M. daubento- in spring at a hibernation site, or in sum- 3.10 Catching bats
nii, M. myotis, M. nattereri, M. mystacinus, 3.8.3 Timing mer for the timing of emergence activities. Invasive methods involving catching and
almost certainly other Myotis species, Ep- Catching should be carried out on dry nights Due to possible swarming activities at such handling of bats, including the use of bat at-
tesicus nilssonii, Barbastella barbastellus, with little wind. Do not catch on more than sites, numbers of emerging bats cannot be tractors, harp traps and mist nets, are not
Plecotus auritus and P. austriacus and pos- three consecutive nights: although there is counted reliably. generally recommended for the purposes
sibly other species (see MESCHEDE & RUDOLPH considerable turnover of individuals each Placing bat boxes or other automatic of surveillance because of the potentially
2004). Some of these bats cannot be sur- night, some bats will learn the position of recording units at cave entrances or other high levels of disturbance to bats. However,
veyed easily using other methods. traps and nets. Swarming activity peaks roosts can make species identification dif- they are extremely useful for initial research
vary between species and depending on ficult because bats often change their typi- prior to setting up surveillance schemes, for
3.8.2 Sampling latitude. In southern Germany it starts with cal sounds inside or close to roosts. Other periodic assessments of bat abundance and
One possible surveillance method would be Eptesicus nilssonii in mid-July, followed by possible positions to use automatic record- when identification of emerging bats must
to place automatic loggers at the entrance Myotis brandtii and Barbastella barbastel- ers may be along linear landscape features, partly be verified by netting of some speci-
to swarming sites to log bat passes per lus at the end of July. The swarming activity such as waterways, hedgerows or forest mens. Netting can also be the only method

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to determine the ratio of some species in tions of nets and traps, so it is best to move 3.11 Ringing 3.12.1 Surveys of winter and summer bat
mixed groups. Furthermore, they may be them every night if catching is to be car- Ringing of bats is not recommended as a roost sites
appropriate when the two main surveillance ried out on consecutive nights (with some surveillance method. Ringing can be used • Any survey should be carried out with
options, bat detector transects or roost exceptions, e.g. at swarming sites). The for particular research projects, often those the approval of the owner or administrator
counts, cannot be employed effectively and fine mist nets designed for catching birds that extend over many years, and can pro- of the roost site (excluding roost sites both
there are no other current alternatives. or those specifically designed for bats are vide very useful information on population located on public land and with open ac-
Catching can be used to identify bat spe- equally successful, but their efficiency de- structure and migration behaviour. Howev- cess).
cies that cannot be recognised with a bat clines rapidly under even moderately windy er, ringing bats to assess population trends • During hibernation, counting and iden-
detector, to confirm the sex and the repro- conditions since bats are better able to de- is inappropriate because of the invasive tification of bats should be done without
ductive status of abundant bats, or to ob- tect moving objects. Harp traps can be used nature of the method and because it is un- waking or catching them.
tain specimens for radio tagging, or in the very successfully in conjunction with nets, likely to provide any useful information for • Only electrical light should be used dur-
case of swarming sites, periodically to as- the latter steering the more alert bats to- surveillance purposes. Ringing generally ing counting. Use of light sources with a
sess changes in species relative abundance wards a trap. requires a license and best practice guid- flame (torches, candles) is unacceptable.
(as described in 3.8.2). Netting is especially successful in for- ance on ringing and catching bats has been Using modern conventional or LED-based
Catching generally requires a license. ests and across rivers. produced by the EUROBATS Advisory Com- lighting systems, specifically designed for
Rigorous training is required in both mittee (EUROBATS Resolution 4.6: Guide- use in caves, it is possible to survey even
putting up nets correctly and in removing 3.10.2 Example: Netting study in Germany lines for the Issue of Permits for the Capture the longest and most technically difficult
bats from them to minimise distress to the A study in Germany (DIETZ & SIMON 2005) and Study of Captured Wild Bats, adopted caves. Strong torches can be used for high
bats. Harp traps are preferred to mist nets showed that the optimum number of net- in 2003; HUTTERER et al. 2005). ceilings and red lights should be used in
since they are more efficient (bats are less ting sites is related to the area being sur- maternity roosts to minimise disturbance.
able to detect them), cause less distress veyed. 3.12 Best practice to be adopted when • The survey (counting) duration as well as
and require minimal training in use. How- Most efficient is the period from May carrying out bat surveys the identification of each animal should be
ever, their small catching area means they to August. Netting should start shortly be- Surveillance of bats and their roosts is a kept to the minimum necessary.
are only useful at roost entrances or where fore sunset and last for six to eight hours, long-term activity, over many years if ro- • During surveys of summer colonies,
the bats are moving along natural flyways although the first three to four hours may bust population trends are to be derived. counting and identification of bats in the
such as woodland paths or small streams. be the most productive since bat activity The methods generally involve repeated roost should be done without catching
They are also heavy and expensive. Mist is often concentrated in the first half of the counts and visits to the same sites at least them if at all possible. Single individuals
nets are more versatile (available in 2.6 to night and whole-night observations make annually and may involve entry into the may be caught only if there is no other way
> 18 m lengths), light and easy to carry but the monitoring very expensive. roost site or catching and tracking of bats. It to identify the species, but this should not
it is possible to be overwhelmed by bats if is therefore very important to follow a strict be done while non-flying young are in the
care is not taken. Mist nets and harp traps Table 2. Optimum number of netting sites related code of practice to ensure that all the sur- colony.
should never be left unattended and should to the size of area being surveyed. veillance activity does not have detrimental • It is important to be as quiet as possible
be checked every few minutes. effects on the populations of bats that are to when carrying out the survey so as not to
area size number of netting sites
be conserved. The recommendations listed disturb the bats. The number of people in a
< 30 ha 1
3.10.1 Sampling below address the main factors to consider survey group (summer and winter) should
Bats are capable of detecting and avoiding 30-250 ha 2 when surveying bats and their roosts and also be kept to a minimum.
both harp traps and mist nets, but careful 251-500 ha 3 follow the best practice guidance on ring- • Survey of roost sites at any time of year
positioning and the element of surprise ing and catching bats (see chapter 3.11). should not be carried out more than twice a
501-1,000 ha 4
allows both to be used with considerable year with at least one month between visits,
> 10 km² 6
success. Capture success declines rapidly and in the event that research on seasonal
if the bats are given time to learn the posi- > 100 km² 8

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

population dynamics is justified, not more

than once every two weeks.
be held softly with one hand and the other
hand used to take the bat out the same way 4 Species accounts
• Any damage to the bat roost structure is it entered the net (e.g. KUNZ 1988, BARLOW
unacceptable (e.g. making holes in walls, re- 1999). EUROBATS Resolution 2.2 originally recom- 4.1 Pteropodidae
moving rubble blocking corridors, draining • When the bat is disentangled it should mended methods for a selected group of 4.1.1 Rousettus aegyptiacus (Geoffroy,
water, removal of parts of the roof or bark be placed in a fabric bag to minimise stress species that could be surveyed in many 1810)
sheets) even where these activities would for the animal. countries to represent the range of bat
increase the effectiveness of the survey. • The time the individual is captured must behaviour and habitat patterns found in
be kept to the minimum necessary – ideally European bat species. This group included:
3.12.2 Catching bats not exceeding ten minutes. Visibly pregnant Rhinolophus hipposideros, Myotis myotis /
• Catching bats around breeding colonies and nursing females should be released M. blythii, M. bechsteinii, M. capaccinii,
when non-flying young are present should immediately after removal from the net. If Eptesicus serotinus / E. nilssonii, Nyctalus
only be carried out if there is no other way many bats are captured at the same time noctula, Miniopterus schreibersii. However,
to identify the species reliably using less then additional catches should be stopped recommendations are provided here for all
invasive methods (e.g. daytime surveys, until all animals have been disentangled. European species, taking into account the
ultrasound detection). If catching bats is • In the event that a large number of bats variety of factors affecting species in indi-
necessary then the number of individuals are caught at the same time, preferably indi- vidual countries.
caught should be kept to a minimum. viduals should be placed in separate bags. Species nomenclature follows the Annex
• No catching should be carried out during Individuals of Rhinolophus spp. should of species occurring in Europe to which the Figure 8. Distribution of Rousettus aegyptiacus.
the expected time of parturition. always be in separate bags. Pregnant and EUROBATS Agreement applies as adopted
• Where nets and other traps are used, they nursing females should be dealt with im- in Resolution 5.3 (2006). Recommended methods
should not be left unattended and should mediately. Methods are listed for each species in or- 1. Counts at maternity roosts, internal, if
be checked every 3-10 minutes, depending • After examination, bats should be re- der of preference, but this order can be dif- access is possible, or emergence.
on numbers of bats present. leased immediately. If a bat does not fly ferent according to the number of bats, the
• When removing bats from the net, check from the hand it should be placed on a tree size of the sites, and the region of Europe. Other information
first if the netting is caught in the bat's trunk or a branch. Captured bats may lower The accounts and methods will need to be Colonies can be hard to find and access de-
teeth, and if so, it should be removed very their body temperature for energetic pur- periodically updated in the light of new in- pends on circumstances e.g. by sea canoe
carefully (this particularly concerns small poses and then need some time to heat up formation and regional variations. for remote colonies. The species emerges
species). Disentanglement should proceed before departure. For this reason bats must Although not specifically included as a very late and flies very low so emergence
as quickly as possible. The animal should not be thrown in the air for release. method, DNA analysis of droppings, wing counts may not be applicable. However,
punch and hair follicle samples, gathered they are faithful to sites.
under licence, can help in the identification This species is considered a pest by lo-
of species which is particularly useful where cal fruit farmers and is often persecuted.
bats occur in mixed groups. These bats can be conspicuous in car head-
The maps provided were compiled by lights as they fly low across roads from tree
the IUCN / SSC Chiroptera Specialist Group to tree. It may be possible to carry out car
and its collaborators in 2005 for the IUCN headlight surveys but at present this meth-
Global Mammal Assessment (IUCN 2008). od requires testing and development of a
For updated maps readers are advised to protocol.
consult the IUCN database and more recent
literature.

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

4.2 Emballonuridae 4.3 Rhinolophidae 4.3.2 Rhinolophus euryale Blasius, 1853 4.3.3 Rhinolophus ferrumequinum
4.2.1 Taphozous nudiventris Cretzschmar, 4.3.1 Rhinolophus blasii Peters, 1866 (Schreber, 1774)
1830

Figure 11. Distribution of Rhinolophus euryale.

Figure 10. Distribution of Rhinolophus blasii. Figure 12. Distribution of Rhinolophus ferrumequi-
Figure 9. Distribution of Taphozous nudiventris. Recommended methods num.
Recommended methods 1. Counts at hibernation sites.
Recommended methods 1. Counts at maternity roots. 2. Counts at maternity roosts, internal or Recommended methods
1. Colony counts, internal or emergence. 2. Counts at hibernation sites. emergence, if colonies are known to be 1. Counts at maternity roosts, emergence
faithful to their roost sites. if possible, from late June to mid-July (if
Other information Other information not mixed with other species and colony
There is only one recorded site in the EURO- The species has a relatively quiet and highly Other information size < 400 individuals), possibly using
BATS Agreement area (in eastern Turkey). directional echolocation call; the use of ul- The species has quiet and highly directional digital photography for large groups in-
The species needs further survey and sta- trasonic detectors is usually inappropriate echolocation calls, and the use of ultrasonic side roosts.
tus assessment before any monitoring can but possible in some sites. It is considered detectors is therefore usually inappropriate 2. Counts at hibernation sites by visual
be entertained (using mist nets and bat de- to be an exclusively cave-dwelling species, but possible in some sites. The species is determination with one winter census
tectors). The known site is a bit remote, but natural or man-made, and appears to be particularly faithful to its hibernation roosts, between 15 December and late Febru-
should be checked as and when possible faithful to its underground roosts. while some maternity colonies move be- ary (when not mixed with other Rhinolo-
(e.g. counting at the roost). The general problem for surveillance of tween roosts. phid species), again using photographic
all “middle“ sized horseshoe bats – R. eury- The species is susceptible to distur- methods for large groups.
ale, R. mehelyi and R. blasii – is that they of- bance. Roost fidelity can be increased
ten form mixed colonies in which the visual through protection of the site. The general Other information
separation of each species is impossible in problem for surveillance of all “middle“ Echolocation calls are intense but highly
south-eastern Europe. Preliminary research, sized horseshoe bats – R. euryale, R. mehelyi directional and observer held detectors
involving catching bats for species identifi- and R. blasii – is that they often form mixed rarely pick up bats unless they are detected
cation and assessment of the proportion of colonies in which the visual separation of moving along commuting routes. However,
each species, is required for each site. This each species is impossible in south-east- static detector systems can be used suc-
could be repeated at five yearly intervals to ern Europe. Preliminary research, involving cessfully to confirm suspected commuting
assess any changes in relative proportions catching bats for species identification and routes and foraging areas within suitable
of each species. assessment of the proportion of each spe- foraging habitats near linear features.
cies, is required for each site.

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

R. ferrumequinum often lives during sum- 4.3.5 Rhinolophus mehelyi Matschie, 4.4 Vespertilionidae ently reliable enough at revealing roost
mer and winter in colonies mixed with 1901 4.4.1 Barbastella barbastellus (Schreber, locations to ensure at least partly accurate
other Rhinolophid species or with Myotis 1774) emergence counts.
emarginatus (PIR et al. 2004). This some- Occasionally individuals will utilise open
times makes monitoring difficult. buildings or barns in very cold weather, but
normally they are active in all milder spells
4.3.4 Rhinolophus hipposideros throughout the winter. In the more continen-
(Bechstein, 1800) tal climate of central Europe B. barbastellus
widely hibernates in colder underground
sites. In these areas there are possibilities
for winter surveillance.
Long-term roost surveillance and moni-
toring should cover both an estimate of the
number of breeding females in a colony
Figure 14. Distribution of Rhinolophus mehelyi. and the quality of the habitat. Foraging
Figure 15. Distribution of Barbastella barbastellus. habitat quality can be assessed by species
Recommended methods richness, particularly botanical and insect
1. Counts at maternity roosts, emergence Recommended methods diversity.
or internal. 1. Bat detector surveys in woodlands.
2. Counts at hibernation sites. 2. Counts at maternity roosts, emergence. 4.4.2 Barbastella darjelingensis
Figure 13. Distribution of Rhinolophus hipposideros. 3. Counts at hibernation sites. (Hodgson, 1855)
Other information
Recommended methods The species has a relatively quiet and high- Other information
1. Counts at maternity roosts, emergence ly directional echolocation call; the use of It is possible to identify B. barbastellus from
or internal. ultrasonic detectors is therefore inappro- echolocation calls with reasonable confi-
2. Counts at hibernation sites. priate. It appears to be faithful to its under- dence and this opens possibilities for car-
ground roosts. rying out field surveys. The species tends
Other information A general problem for the monitoring to be scarce in the landscape so is difficult
The species has a quiet and highly direc- of all „middle“ sized horseshoe bats in the to encounter, but commutes long distances
tional echolocation call; the use of ultrason- Balkans – R. euryale, R. mehelyi and R. blasii along regular flight lines to foraging areas,
ic detectors is therefore inappropriate. It – is that they often form mixed colonies in which aids detection. Colony counts are dif-
appears to be faithful to its maternity roosts which the visual separation of each species ficult because colonies constantly divide
and depends completely on underground is impossible. Preliminary research involv- and move locations.
sites for hibernation. ing catching of bats for species identifica- Accurate population estimates for each Figure 16. Distribution of Barbastella darjelingensis.
In western Europe, summer emergence tion and assessment of the proportion of colony will rely on the invasive techniques
counts are favoured over hibernation counts each species is required for each site, which of a radio-tracked individual coupled with Recommended methods
because populations are more aggregated can be repeated at five yearly intervals. infrared camcorder roost exit counts. This 1. Bat detector surveys along water courses
during the breeding season than during procedure is best undertaken during early and scattered trees and shrubs.
hibernation. In central Europe counts at hi- August when the colonies are at their larg-
bernation sites are preferred. est and most stable. Although invasive,
radio-tracking is the only method consist-

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

4.4.3 Eptesicus bottae (Peters, 1869) 2. Counts at hibernation sites in parts of The species is synanthropic throughout transmitters on individuals caught at forag-
central and eastern Europe and higher most of its range. It is therefore highly de- ing / drinking sites.
altitudes in the southern part of its distri- pendent on conservation measures and the The species has calls that are distinctive
bution. attitude of private house owners. For roof- from all other species (except in cluttered
3. Counts at maternity roosts, emergence inhabiting serotines, at least two counts habitats, where there is a risk of confusion
(but may have low site fidelity in some are recommended: one in mid-May after with Pipistrellus species). It is important
places). the establishment of colonies, and one in to take account of the vertical distribution
mid- / end-June before young become vo- of this species when foraging as it is often
Other information lant. Crevice-inhabiting colonies differ al- found flying above the tree canopy at rela-
The species has loud calls which are dis- most daily in numbers and all known roosts tively high altitudes compared with other
tinctive from all other species. of the colony have to be followed to get ac- species. H. savii, like several other species,
curate numbers. Radio transmitters can be seems to roam widely to different forag-
4.4.5 Eptesicus serotinus (Schreber, 1774) fitted to individuals caught at drinking / for- ing areas (RUSSO & JONES 2003) to feed on
Figure 17. Distribution of Eptesicus bottae. aging sites to locate roosts, e.g. in countries swarming insects, so counts could vary a
where there are no known roosts. lot within a short period and should be re-
Recommended methods peated many times during summer.
1. Bat detector surveys. 4.4.6 Hypsugo savii (Bonaparte, 1837)
4.4.7 Myotis alcathoe von Helversen &
Other information Heller, 2001
This species has a distinctive echolocation
call (HOLDERIED et al. 2005).

4.4.4 Eptesicus nilssonii (Keyserling &

Blasius, 1839)

Figure 19. Distribution of Eptesicus serotinus.

Recommended methods
1. Bat detector surveys, including car sur-
veys. Figure 20. Distribution of Hypsugo savii.
2. Counts at maternity roosts, emergence
(or internal in suitable roosts). Recommended methods Figure 21. Distribution of Myotis alcathoe.
3. Remote automatic recording. 1. Bat detector surveys.
Recommended methods
Other information Other information 1. Mist-netting and identification in the
The species has loud echolocation calls Survey can possibly be carried out using hand is the only known option at present
Figure 18. Distribution of Eptesicus nilssonii. which are distinctive from all other species balloons with remote recording equipment and can provide some useful informa-
(however in cluttered habitats there is risk attached. tion.
Recommended methods of confusion with Nyctalus leisleri and Ves- The roosts of H. savii are difficult to
1. Bat detector surveys, including car sur- pertilio murinus). Hibernation sites for the find, although some roosts can be found
veys. species are not generally known. in buildings. They can be located by fitting

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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

Other information 4.4.9 Myotis bechsteinii (Kuhl, 1817) proportions and survival rates to make pop- Other information
The echolocation calls of this species can- ulation predictions based on male numbers It is possible to use photographic methods
not be separated for identification purposes alone. Counting juvenile bats at swarming to identify species (see also 4.4.17). Identi-
from those of other Myotis species. sites may hold possibilities, but the bats fication of the difference from M. myotis is
Molecular analyses are required to con- need to be caught and handled to identify difficult with ultrasonic detectors and also
firm species occurrence in areas where this them. Swarming sites are not known across visually in mixed colonies. M. blythii may
species has not yet been recorded. wide areas so how relevant the data would have a distinctive white patch on the top
be from the few currently known swarming of its head, making it distinguishable from
4.4.8 Myotis aurascens Kuzyakin, 1935 sites is unknown. M. myotis while roosting, although identi-
Echolocation calls are very quiet and fication remains difficult. In most cases it
often difficult to separate from some other would be wise not to distinguish between
Myotis species. For long-term population M. blythii and M. myotis where they live in
monitoring the numbers of breeding fe- mixed colonies. These species are faithful
Figure 23. Distribution of Myotis bechsteinii. males in a selected number of maternity to their summer and winter roosts.
roosts should be assessed and estimated Preliminary research, involving catch-
Recommended methods every five years. A habitat assessment ing bats for species identification and as-
1. Use artificially produced social calls to should form part of this exercise. sessment of the proportion of each spe-
attract foraging specimens into mist nets cies, is required for each site. This could be
or harp traps and follow up with radio- 4.4.10 Myotis blythii (Tomes, 1857) repeated at five yearly intervals to assess
tracking to locate roosts. Use infrared any changes in relative proportions of each
camcorders to carry out emergence species.
Figure 22. Distribution of Myotis aurascens. counts.
2. Surveys at swarming sites. 4.4.11 Myotis brandtii (Eversmann, 1845)
Recommended methods
1. Mist-netting and identification in the Other information
hand is the only known option at present This species has a close association with
and can provide some useful informa- semi-natural woodland. The bats habitually
tion. forage in tree crowns at some distance from
the ground. This behaviour makes it parti-
Other information cularly difficult to monitor their quiet echo-
Molecular analyses are required to confirm location calls with ultrasonic detectors.
species occurrence in areas where this spe- The constant shifting and dividing of Figure 24. Distribution of Myotis blythii.
cies has not yet been recorded. maternity colonies makes accurate counts
difficult and the species rarely hibernates Recommended methods
where it can be counted. 1. Counts at hibernation sites.
M. bechsteinii is caught in sufficient 2. Counts at maternity roosts, internal. For Figure 25. Distribution of Myotis brandtii.
numbers at mating swarming sites in late separate colonies emergence counts are
summer and this could offer a potential for possible. Recommended methods
surveillance. These swarming animals are, 1. Counts at hibernation sites with mass oc-
however, predominantly male and too little currence of the species.
is currently known about male / female birth 2. Surveys at swarming sites.

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3. Netting over water bodies or in forest 2,000 specimens in Croatia). Ultrasonic de- 4.4.14 Myotis daubentonii (Kuhl, 1817) 4.4.15 Myotis emarginatus (Geoffroy, 1806)
clearings could be useful if the other tectors are inappropriate for this species
methods are not appropriate. where it is sympatric with M. daubentonii.
The species may form mixed colonies
Other information with M. myotis / M. blythii / Miniopterus
Ultrasonic detectors are not appropriate for schreibersii.
this species because of the current impos- In some roosts in south-western Europe
sibility of distinguishing it from other close- it is possible to count the young using pho-
ly related Myotis species. tography after the adults have emerged,
The species can be confused with M. al- which could give a measure of colony pro-
cathoe and M. mystacinus which are very ductivity. This procedure may be inappro-
similar. Punch samples of wing membrane priate for large colonies in south-eastern
can be gathered, under licence, for possible Europe.
later confirmation of identification. Figure 28. Distribution of Myotis daubentonii. Figure 29. Distribution of Myotis emarginatus.
4.4.13 Myotis dasycneme (Boie, 1825)
4.4.12 Myotis capaccinii (Bonaparte, 1837) Recommended methods Recommended methods
1. Bat detector surveys where Myotis ca- 1. Counts at hibernation sites.
paccinii does not occur, using point Counts at maternity roosts, internal. This
count method around water bodies us- is the preferred method in a large part of
ing a torch to confirm identity from flight Europe.
style. 2. Surveys at swarming sites.
2. Counts at hibernation sites, although the
species can be hard to identify because Other information
it may use crevices during hibernation. Preferably one hibernation count should be
3. Surveys at swarming sites. carried out to avoid disturbance, but with
4. Remote automatic recording under a maximum of two, as the species is very
bridges. sensitive.
Figure 27. Distribution of Myotis dasycneme. There is a risk of confusion with other
Figure 26. Distribution of Myotis capaccinii. Other information middle-sized Myotis species in hibernation
Recommended methods The foraging style means that the species sites when animals roost in deep crevices.
Recommended methods 1. Bat detector surveys, using point count can easily be identified foraging over water The species uses several roosts and the
1. Counts at hibernation sites (south-east- method around water bodies. bodies, but there is a high risk of confusion number of individuals in maternity roosts
ern Europe). 2. Counts at maternity roosts, emergence. where M. capaccinii and M. dasycneme are changes from one year to another or even
2. Counts at maternity roosts, internal (south- 3. Counts at hibernation sites. also present. from the beginning to the end of the breed-
western and south-eastern Europe). 4. Surveys at swarming sites. ing season (PIR 2004), making surveillance
3. Bat detector surveys, except where the using colony counts difficult. In Croatia, 1 m2
species is sympatric with M. daubentonii. Other information corresponds to about 2,000 individuals.
It is possible to distinguish this species There is no evidence that bat detector
Other information from other trawling bats acoustically and transects are effective for this species.
It is possible to use digital photography for visually (BRITTON et al. 1997).
large colonies (1 m2 corresponding to about

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4.4.16 Myotis hajastanicus Argyropulo, 4.4.17 Myotis myotis (Borkhausen, 1797) 4.4.18 Myotis mystacinus (Kuhl, 1817) 4.4.19 Myotis nattereri (Kuhl, 1817)
1939

Figure 31. Distribution of Myotis myotis. Figure 32. Distribution of Myotis mystacinus. Figure 33. Distribution of Myotis nattereri.
Figure 30. Distribution of Myotis hajastanicus.
Recommended methods Recommended methods Recommended methods
Recommended methods 1. Counts at maternity roosts; emergence 1. Counts at hibernation sites with mass oc- 1. Counts at hibernation sites. The species
There are no known methods for this spe- counts are possible for monospecific col- currence of the species. is often found in underground sites and
cies, but the same methods as for other onies (particularly in the north). However, 2. Surveys at swarming sites. is easy to identify in central Europe; there
Myotis species can probably be used. Only the species often uses many exit points 3. Mist-netting in suitable habitats could be is a risk of confusion with other middle-
known from Armenia, where internal count- so care needs to be taken when organis- useful if no other methods are appropri- sized Myotis in southern Europe.
ing is the only method possible at present. ing the count. ate. 2. Counts at maternity roosts, internal.
2. Counts at hibernation site, again using 3. Surveys at swarming sites.
Other information photographic methods. Other information 4. If no other alternative is possible then
There is only one locality known, in Arme- Ultrasonic detectors are inappropriate for mist-netting in forests provides some in-
nia, with small groups of 1-5 individuals. Other information this species because of the current impos- formation.
Internal counts in large attic roosts or caves sibility of distinguishing it from other close-
are possible using digital photography (1 m2 ly related Myotis species (see M. alcathoe). Other information
corresponding to about 1,300 specimens in The species can be confused with M. al- Internal counts at maternity roosts can
Croatia, 1,000 specimens in Portugal). Identi- cathoe and M. brandtii (see under those be very difficult because this is a crevice-
fication of the difference from Myotis blythii species). dwelling species and its presence is often
is difficult with ultrasonic detectors and also not obvious.
visually in mixed colonies. M. blythii may Surveillance using ultrasonic detectors
have a distinctive white patch on the back is not recommended because of confusion
of its head, making it distinguishable from with other foraging Myotis species. It may
M. myotis while roosting, although identi- be recognised from time-expansion record-
fication remains difficult. In most cases it ings of echolocation calls, especially in clut-
would be wise not to distinguish between tered habitat, due to its broad frequency
M. blythii and M. myotis where they live in bandwidth signals (RUSSO & JONES 2002).
mixed colonies. These species are faithful to Emergence counts at maternity roosts
their summer and winter roosts. are also not very reliable because of the

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unpredictable behaviour of emerging bats, 4.4.21 Myotis punicus Felten, 1977 4.4.23 Nyctalus lasiopterus (Schreber, nier and mesh size). In Hungary mist-netting
frequently returning to the roost and re- 1780) at such localities has been very successful.
emerging, causing confusion in the counts. Absolute acoustic separation from N. noc-
tula may not be possible except in very
4.4.20 Myotis nipalensis (Dobson, 1871) open habitats.

4.4.24 Nyctalus leisleri (Kuhl, 1817)

Figure 35. Distribution of Myotis punicus.

Figure 37. Distribution of Nyctalus lasiopterus.
Recommended methods
1. Counts at maternity roosts, internal. Recommended methods
Figure 34. Distribution of Myotis nipalensis. Emergence counts are also possible, 1. Bat detector surveys.
but the large size of colonies can make
Recommended methods counting quite difficult. Other information Figure 38. Distribution of Nyctalus leisleri.
1. Counts at hibernation sites with mass oc- The use of accoustic lures may be effective.
currence of the species. 4.4.22 Myotis schaubi Kormos, 1934 The species can be confused with N. noc- Recommended methods
2. Surveys at swarming sites. tula, but also with Tadarida teniotis, and 1. Bat detector surveys, including car sur-
3. Netting over water bodies or in forest therefore computer analysis of echoloca- veys.
clearings could be useful. tion recordings is the only way to identify 2. Counts at maternity roosts, emergence,
the three species (BEC et al. 2008). where species roosts in buildings.
Other information N. lasiopterus is a large heavy bat with 3. Surveys at mating roosts.
Ultrasonic detectors are inappropriate for less manoeuvrable flight than other smaller
this species because of the current impos- bats. It is also highly associated with water Other information
sibility of distinguishing it from other close- bodies as it seems to need a regular water The species echolocation calls overlap with
ly related Myotis species. supply (possibly connected with its rapid Vespertilio murinus and Eptesicus seroti-
The species can be confused with M. al- flight) so individuals visit drinking places nus, and can be confused with N. noctula,
cathoe and M. brandtii. Punch samples of regularly. This means that mist-netting can the exact type of call dependent on the
wing membrane can be gathered, under be a good method for survey. environment where it is found. Identifica-
licence, for possible later confirmation of Figure 36. Distribution of Myotis schaubi. Mist nets placed on the banks of small tion with reasonable confidence requires
identification. ponds or streams with calm surfaces where surveyors who have some previous experi-
Recommended methods the species comes to drink can be used to ence of this species.
No colonies are known, but the methods provide information on sex ratio and repro- Absolute acoustic separation from
would be the same as for M. nattereri. ductive condition. It is important to use the N. noctula may not be possible except in
same locations for the mist net each time very open habitats.
and mist nets must be of similar quality (de-

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The mating calls of the species can be eas- 4.4.26 Otonycteris hemprichii Peters, 1859 Other information 4.4.29 Pipistrellus pipistrellus (Schreber,
ily identified using time-expansion detec- It is important to be aware of the overlap 1774)
tors and may be useful for monitoring from between calls of P. kuhlii and P. nathusii. So-
August to early October. cial calls may resolve all risk of confusion
between the two species (RUSSO & JONES
4.4.25 Nyctalus noctula (Schreber, 1774) 1999). See RUSSO & JONES (2002) for P. kuhlii
frequencies.

4.4.28 Pipistrellus nathusii (Keyserling &

Blasius, 1839)

Figure 40. Distribution of Otonycteris hemprichii.

Figure 43. Distribution of Pipistrellus pipistrellus.
Recommended methods
1. Counts at maternity roosts. Recommended methods
2. If no other methods are available then 1. Bat detector surveys, including car sur-
Figure 39. Distribution of Nyctalus noctula. netting at water bodies can provide some veys.
information. 2. Counts at maternity colonies, emer-
Recommended methods gence.
1. Bat detector surveys, including car sur- 4.4.27 Pipistrellus kuhlii (Kuhl, 1817) 3. Surveys at mating roosts.
veys. Figure 42. Distribution of Pipistrellus nathusii.
2. Surveys at mating roosts, of calling males Other information
during the mating season. Recommended methods There is little overlap in dominant frequen-
3. Counts at maternity roosts. 1. Bat detector surveys. cies of P. pipistrellus and P. pygmaeus (< 5%
4. Counts at hibernation sites. 2. Surveys at mating roosts. overlap at maternity roosts, JONES & VAN
3. Counts at maternity roosts, emergence. PARIJS 1993).
Other information 4. Surveys at swarming sites. The species has very distinctive and
Counts at maternity and hibernation sites loud echolocation calls mostly around 45
probably do not give a reliable index of Other information kHz and can readily be identified using a
N. noctula population density. However, Broadband detectors can be used on field bat detector, except in some southern ar-
the species can be identified easily with a surveys with post-survey species identifi- eas where the distinctive calls are at 49 kHz.
bat detector, except where N. lasiopterus is cation through sonogram analysis. But be- Frequency partly overlaps with Miniopte-
present. It is possible to hear this species in Figure 41. Distribution of Pipistrellus kuhlii. ware overlap with P. kuhlii. Social calls may rus schreibersii, social calls are needed to
roosts during the day time. resolve all risk of confusion between the resolve the risk of confusion. The use of
Recommended methods two species (RUSSO & JONES 1999). P. nathu- buildings as maternity roosts by this spe-
1. Bat detector surveys. sii is a highly migratory species (HUTTERER cies means that colony counts during the
2. Counts at maternity roosts. et al. 2005). summer are also an appropriate method.
However, it should be noted that this is a
very mobile species, with colonies moving

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location within and between years. Colonies readily be identified using a bat detector. groups of two or three with a few minutes 4.4.33 Plecotus kolombatovici Dulic, 1980
may also grow and shrink in size during the The use of buildings as maternity roosts by between groups. The species can, therefore,
breeding season, making colony counts of this species means that colony counts dur- take a long time to emerge from roosts, so
questionable reliability. ing the summer may be a good monitoring visibility of bats may be an issue, particu-
method. Colonies of P. pygmaeus are larger larly for larger colonies where the last bats
4.4.30 Pipistrellus pygmaeus (Leach, and more stable than those of P. pipistrel- will be emerging quite late.
1825) lus, perhaps rendering them more suitable
to this type of monitoring. 4.4.32 Plecotus austriacus (Fischer, 1829)

4.4.31 Plecotus auritus (Linnaeus, 1758)

Figure 47. Distribution of Plecotus kolombatovici.

Recommended methods
1. Counts at maternity roosts would prob-
ably give a reliable index of P. kolombato-
vici population density. Possible problem
Figure 44. Distribution of Pipistrellus pygmaeus. could be identification of this species in
Figure 46. Distribution of Plecotus austriacus. areas of sympatry with other Plecotus
Recommended methods species.
1. Bat detector surveys, including car sur- Figure 45. Distribution of Plecotus auritus. Recommended methods 2. Locating new colonies using bat detec-
veys. 1. Counts at maternity roosts, both internal tors during early morning swarming in
2. Counts at maternity roosts, emergence. Recommended methods and emergence. front of summer roost sites.
3. Surveys at mating roosts might be useful 1. Counts at maternity roosts, emergence. 2. Counts at hibernation sites, but only in
as social calls of this species and P. pipi- 2. Counts at hibernation sites. some parts of the species range. 4.4.34 Plecotus macrobullaris Kuzyakin,
strellus are usually (but not always) 3. Surveys at swarming sites. 3. If no other alternative is possible then 1965
straightforward to separate. 4. If no other alternative is possible then mist-netting provides some information.
4. Surveys at swarming sites. mist-netting provides some information.

Other information Other information

Beware of overlap of calls from P. pygmae- The species is predominantly a woodland
us with those of M. schreibersii where the species and has very quiet echolocation
two species are sympatric (RUSSO & JONES calls. It is not usually encountered in the
2002). There is little overlap in dominant fre- open countryside, so it is not suitable for
quencies of P. pygmaeus and P. pipistrellus bat detector surveys. It forms fairly stable
(< 5% overlap at maternity roosts, JONES & colonies and tends to be philopatric, espe-
VAN PARIJS 1993). cially when roosting in buildings.
The species has very distinctive and This species tends to emerge late in the
loud echolocation calls at 55 kHz and can evening and have a pattern of emerging in Figure 48. Distribution of Plecotus macrobullaris.

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Recommended methods 4.4.36 Vespertilio murinus Linnaeus, 1758 4.4.37 Miniopterus schreibersii (Kuhl, 4.5 Molossidae
1. Counts at maternity roosts should give 1817) 4.5.1 Tadarida teniotis (Rafinesque, 1814)
reliable population density information.
2. If no other alternative is possible then
mist-netting provides some information.

Other information
Bat detector surveillance is almost impos-
sible and is not recommended. Preliminary
mist-netting surveys may be required to de-
termine true range and distribution.

4.4.35 Plecotus sardus Mucedda, Kiefer,

Pidinchedda & Veith, 2002 Figure 50. Distribution of Vespertilio murinus.
Figure 51. Distribution of Miniopterus schreibersii. Figure 52. Distribution of Tadarida teniotis.
Recommended methods
1. Counts at maternity roosts, emergence; Recommended methods Recommended methods
internal may sometimes be possible. 1. Counts at hibernation sites. 1. Bat detector surveys in foraging habitats.
2. Bat detector surveys (line transects). 2. Counts at maternity roosts, internal. Echolocation calls are quite distinctive
3. Surveys at mating sites. 3. Bat detector surveys. and can be heard at long range (RUSSO &
JONES 2002).
Other information Other information 2. Counts at maternity roosts, emergence,
The species has distinctive social calls, but A visual count should be undertaken as are possible, mainly for colonies roost-
echolocation calls can be confused with quickly as possible inside the cave or mine, ing in buildings.
Eptesicus serotinus and Nyctalus leisleri assessing the size of the colony by estimat-
(SCHAUB & SCHNITZLER 2007). V. murinus is a ing, through photography (stereoscopic if Other information
Figure 49. Distribution of Plecotus sardus. long-distance migrant in eastern and cen- the roof is sloping), the square metre area T. teniotis emits loud and audible echolo-
tral Europe. which it covers (1 m2 corresponding to cation calls, so sound surveys in summer
Recommended methods about 2,000 individuals). are recommended for surveillance of the
Surveys are required to assess roost loca- Beware of overlap of calls from P. pyg- species for trained operators. The presence
tions. maeus / P. pipistrellus with those of of Nyctalus lasiopterus with overlapping
M. schreibersii where the two / three spe- echolocation calls makes confirmation of
cies are sympatric (RUSSO & JONES 2002). identification with computer analysis nec-
This species gathers in large numbers essary (BEC et al. 2008).
during winter. Colonies roosting above 15 m
may be very difficult to count accurately.
Females of one maternity colony can use
several roosts in an area. Foraging areas
of the species include edges of woodlands,
hedgerows, orchards, and street lamps in
some places.

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4.6 Summary table of species and methods Table 3 (cont.)

Table 3. Recommended methods for the monitoring and surveillance for European bat species. Methods
The numbers in columns indicate the order of preference of methods for each species. This order can
Species Bat detector survey Colony counts Hibernation Mating Swarming Remote Catching
change according to the number of bats, the size of the sites, and the region of Europe.
Field Car Water Internal Emergence survey roosts sites recording bats

Myotis schaubi 2 1 3
Methods
Nyctalus lasiopterus 1
Species Bat detector survey Colony counts Hibernation Mating Swarming Remote Catching
survey roosts sites recording bats Nyctalus leisleri 1 1 2 3
Field Car Water Internal Emergence
Pteropodidae Nyctalus noctula 1 1 3 4 2

Rousettus aegyptiacus 1 Otonycteris hemprichii 1 2

Emballonuridae Pipistrellus kuhlii 1 2

Taphozous nudiventris 1 1 Pipistrellus nathusii 1 3 2 4

Rhinolophidae Pipistrellus pipistrellus 1 1 2 3

Rhinolophus blasii 1 1 2 Pipistrellus pygmaeus 1 1 2 3 4

Rhinolophus euryale 2 2 1 Plecotus auritus 1 2 3 4

Rhinolophus Plecotus austriacus 1 1 2 3

1 2
ferrumequinum Plecotus kolombatovici 1
Rhinolophus hipposideros 1 1 2 Plecotus macrobullaris 1 2
Rhinolophus mehelyi 1 1 2 Plecotus sardus
Vespertilionidae Vespertilio murinus 2 1 1 3

Barbastella barbastellus 1 2 3 Miniopterus schreibersii 3 2 1

Barbastella darjelingensis 1 Molossidae

Eptesicus bottae 1 Tadarida teniotis 1 2

Eptesicus nilssonii 1 1 3 2

Eptesicus serotinus 1 1 2 3

Hypsugo savii 1

Myotis alcathoe 1

Myotis aurascens 1

Myotis bechsteinii 1 2 1

Myotis blythii 2 2 1

Myotis brandtii 1 2 3

Myotis capaccinii 3 2 1

Myotis dasycneme 1 2 3 4

Myotis daubentonii 1 2 3 4

Myotis emarginatus 1 1 2

Myotis hajastanicus 1

Myotis myotis 1 1 2

Myotis mystacinus 1 2 3

Myotis nattereri 2 1 3

Myotis nipalensis 1 2 3

Myotis punicus 1 1

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5 National bat monitoring annually some priority species and to test

new methods.
it gave the ministry in charge of the environ-
ment the incentive to start an Action Plan.

programmes
Finally, in order to fill the gaps of the two In 2004, a new assessment of bat popu-
previous surveys, regional surveillance was lations was made, nearly ten years after the
carried out mainly by counting rhinolophids 1995 report. This assessment showed that
Some examples of bat monitoring pro- is checked at regular time intervals, and in hibernacula and mapping the distribu- the disparity between regions previously
grammes in European countries are pro- the presence and size of the colony can be tion of all species. All work has been carried reported still exists, although systematic
vided here to show how the guidelines on estimated according to the number (clas- out on a voluntary basis. inventories have started in some regions,
survey methods can be applied in practice sified) of droppings. This method is espe- explaining the increase in numbers of sites
for a range of species. cially useful if monitoring a large number of 5.2.2 Long-term winter and summer and bats. However, some large areas of the
roosts and emergence counts are not pos- surveys country still need to be investigated.
5.1 Belgium sible. It minimises the disturbance caused In 1995 the first national survey attempted As data from some areas or for some
5.1.1 Introduction by internal counting. to estimate the populations of the twelve species had not been communicated at the
Bat monitoring in Wallonia started in the These long-term standardised surveys Habitats Directive Annex II species (ROUÉ time of the compilation, a full analysis could
1940s and has been organised by Jacques show country level population trends of et al. 1997). The number of bats was re- not be carried out. But some comment can
Fairon (National Royal Institute for Natural all species and in relation to the natural re- corded for both hibernation sites and nurs- be made for Miniopterus schreibersii.
Sciences, Brussels) from the 1960s. Since gions where they occur. ery roosts selected by surveyors. In winter, After the exceptional mortality that af-
1990 it has been part of the regional sur- bats were counted inside the roosts by vol- fected Miniopterus schreibersii in France,
veillance programme. Monitoring methods 5.2 France unteers. Disturbance of bats was kept to a Portugal and Spain in 2002, population
have been established for winter and sum- 5.2.1 Introduction minimum, with one visit only, no handling decline on a national scale has been ob-
mer surveys. Bat surveillance has been ongoing in France (excluding some for identification, and bats served, but is still difficult to evaluate in the
for several decades, and has provided infor- hidden deep in cracks), a small number of absence of national monitoring of all hiber-
5.1.2 Surveying hibernacula mation on the dramatic decline of many bat counters, and limiting the time spent in the nation and maternity roosts. For this spe-
A number of representative underground species, particularly horseshoe bats (BROS- hibernacula to an absolute minimum. Sites cies, the absolute protection of its roosts
sites per natural region of Wallonia have SET 1978, BROSSET et al. 1988). However, sur- were surveyed preferably on the same day seems to be the prerequisite that will allow
been identified (95 out of 712 underground veys were restricted to a few main roosts each year, usually from mid-January to mid- its population to recover.
sites have been selected). Timing and and often carried out at a regional level (e.g. February. In summer, colony counts were
number of visits and use of equipment have FAUGIER 1983, ARIAGNO & SALAÜN 1991, FAUGIER traditionally carried out from late May to
been standardised (no carbid lamps!). Em- & ISSARTEL 1993, NOËL 2002). mid-July depending on the species. Counts
phasis is on respect of conservation issues In the 1990s a long-term surveillance were either inside the roost for a very short
(no handling of bats, avoidance of distur- programme for Annex II Habitats Directive visit or during emergence with or without a
bance to hibernating animals). species was initiated during the National bat detector.
Bat Meeting in Bourges. This surveillance This investigation highlighted a great
5.1.3 Surveying summer roosts was planned on an annual basis for winter- disparity between regions, as the majority
Estimating colony size and change in size ing Rhinolophus ferrumequinum and was of the surveys were conducted in the north-
is carried out through counts of droppings. partly possible because of the dramatic in- ern half of the country and only localised
Maternity roosts are located and species crease in the number of bat workers. Later information came from the southern part. A
identified. Roosting places within the site on, during the period 1999-2003, a five-year report was produced in 1995 to make the
are identified and plastic foil of standard- Action Plan for bats was implemented by national and local authorities aware of the
ised size is put under the main roosting the French mammal society (SFEPM). One necessity to conserve these mammals and
places of the colony. The plastic sheeting aim of this first Action Plan was to survey

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Table 4. Seasonal counting of French bat roosts at a nine-year interval, after ROUÉ et al. (1997), GROUPE Table 5. Extent of the five-year surveillance program in France.
CHIROPTÈRES SFEPM (2010). * if possible all sites; ** only roosts >100 individuals.
Rhinolophus ferrumequinum was also surveyed in 1999 (ROS 2002). Myotis myotis and Myotis blythii are
sympatric in the south of France and even form mixed maternity colonies; as they cannot always be identi- Winter Summer Total
fied separately, a total for the two species combined is presented in addition to the separate counts. Species Method Regions
North South North South sites

Winter Summer Rhinolophus ferrumequinum ✓ ✓ general 10 20

Species Year
Bats Sites Bats Sites Rhinolophus hipposideros ✓ ✓ general 10 20

1995 21,268 810 6,430 270 Rhinolophus euryale * ✓ ✓ general 12 28

Rhinolophus ferrumequinum 1999 28,422 1,433 10,572 210 Myotis capaccinii * ✓ specific 3 14
2004 42,043 1,823 19,171 291 Myotis emarginatus ✓ ✓ general 11 22
1995 5,930 909 10,644 578 Myotis myotis ✓ general 8 16
Rhinolophus hipposideros
2004 15,268 2,199 31,212 1,496 Barbastella barbastellus ** ✓ general 6 6
1995 2,899 51 3,616 49 Miniopterus schreibersii * ✓ ✓ specific 10 22
Rhinolophus euryale
2004 9,367 117 6,524 48
1995 5 1 0 0
Rhinolophus mehelyi
2004 1 1 0 0 5.2.3 Five-year surveillance programme etc.). The winter survey was scheduled be-
1995 13,035 681 37,126 252 1999-2003 tween 15 January and 10 February, and
Myotis myotis
2004 15,520 1,363 52,449 311 The first national action plan for bats the summer survey between 1 June and
1995 1,116 9 8,685 32 (SFEPM 1999), included a programme of 15 July, before the young start flying, in or-
Myotis blythii roost surveys of eight Habitats Directive der to count them at night once the adults
2004 2,537 118 21,362 97
1995 14,151 690 45,011 284 Annex II species in winter and/or summer have left to forage.
Myotis myotis / blythii (ARTHUR et al. 2000).
2004 18,057 1,481 73,811 408
1995 541 35 1,525 21
Due to the large number of roosts for six 5.2.4 Regional surveys
Myotis capaccinii species, only the two most important ones Regional surveillance mainly involves rhi-
2004 720 78 3,803 14
for each region and for each study season nolophids that are easy to count in hiber-
1995 18 5 0 0
Myotis dasycneme were selected (Table 5). During the five-year nacula, and was initiated some decades
2004 23 6 0 0
period the surveillance of some roosts was ago in some localities (ARIAGNO & SALAÜN
1995 9,670 345 7,681 123
Myotis emarginatus abandoned due to the disappearance of 1991, LUSTRAT 1994, BARATAUD & JOURDE 1999,
2004 18,240 751 35,251 198
the colony or of the roost itself or because LUSTRAT 2001, ARIAGNO et al. 2002, AUBOIN
1995 732 239 191 30
Myotis bechsteinii there was no volunteer to continue the sur- 2002, NOËL 2002, LUSTRAT & JULLIEN 2003,
2004 823 528 135 8
vey. Survey protocols for each species were BOIREAU 2006). For example, in the Ardèche
1995 1,983 239 1,155 51
Barbastella barbastellus similar (see long-term surveillance) except department (south-eastern France), winter
2004 4,886 528 3,141 200
for Miniopterus schreibersii (a species that and summer roosts (mainly caves) have
1995 211,109 45 114,056 95
Miniopterus schreibersii forms very large colonies, see 5.2.7.) and been surveyed annually since 1953 (FAUGIER
2004 74,786 52 57,515 50
Myotis capaccinii (often found in mixed 1983, FAUGIER & ISSARTEL 1993).This long-term
colonies, see 5.2.8.). surveillance deals with seven cave-dwell-
The information collected included site ing species (Rhinolophus ferrumequinum,
characteristics (location, type of roost, pro- R. hipposideros, R. euryale, Myotis myotis,
tection and disturbance), the date of survey, M. blythii, M. emarginatus and Miniopterus
the number of bats as well as some other schreibersii) in a total of 238 sites. The data
data (isolated individuals, clusters, corpses are particularly good for a comparison be-

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tween decades 1953-1963 and 1981-1991 On average over 300 volunteers take part respond to a percentage of additional sur- • With the frame as close as possible un-
because there was similar recording effort every year. Volunteer training is organised face area according to the slope. der the colony take a picture. If the density
in the field. by local bat groups across the country dur- • Index 0 = 0% (nonexistent or insigni- of the group is not uniform or if spaces of
Results of various field surveys (roost ing field surveys conducted by licensed bat ficant relief: slope from a few cm² appear in between the bats, take
counts, mist-netting, bat detector records) workers. the horizontal < 20°) one picture of each of the different zones.
are usually stored on a regional basis. These • Index 1 = +10% (slope around 30°) • Attach a light colour wooden ruler (1 m
databases are then used to map the distri- 5.2.6 Databases • Index 2 = +25% (slope around 50°) long) at right angles to the end of the
bution of the species and possibly identify Data are stored in regional databases and • Index 3 = +35% (slope around 60°) pole and place as close as possible to the
trends in the evolution of their range. For population trend information is made • Index 4 = +55% (slope around 70°) colony. Take a picture focusing on the ruler
example in the region Midi-Pyrénées, all bat available through reports and sometimes • Index 5 = +75% (slope around 80°) (its light colour will help doing it even in low
contacts are recorded by volunteers, either publications. Data for national reports are On a sketch showing the form of the group light). If you cannot get the whole colony on
on field sheets or stored directly in a local then extracted and centralised by the pro- the appropriate index will be noted for the the same shot, take a picture of the differ-
Access database. Once a year the local da- gramme coordinators of SFEPM. No nation- different relief areas. ent parts, noting the characteristic rocky
tasets are collected into a regional database al database is available. features which surround the colony. Never
for analysis and mapping. For each spe- In the field use a focal length less than 28 mm because
cies, bat workers must give information on 5.2.7 Recommended surveillance methods a) Height of the colony < 8 m picture distortions will affect the results.
the site: name of the locality, map number for Miniopterus schreibersii
(IGN 1 / 50,000) and quadrant (8 quadrants This survey concerned ten regions for a b) Height of the colony > 8 m
per map) or preferably geographic coordi- total of 25 hibernation sites which were If the colony is out of reach of the pole, the
nates (altitude included), date, number of visited between 15 and 25 January for the margin of error will vary and it will be nec-
bats, type of contact (seen alive, corpses, most important ones and, if necessary, until essary to mention the method used for the
droppings), bat activity (breeding, hibernat- 10 February for the others. estimation. The most efficient way is the
ing, transit etc.), age and breeding status, following:
habitat. Standardised field sheets with cod- Protocol • Using a torch with a narrow beam, first
ings are provided to bat workers. Maps of The aim is to estimate the size of the colo- calculate the beam diameter at different dis-
bat presence / absence are then easily ob- ny by counting the number of individuals tances (e.g. every meter from 8 to 25 m).
tained on any kind of information: breeding and the surface area covered by the colony • Taking landmarks, evaluate as precise-
colonies, hibernating sites, mating roosts on a photograph (with an aliquot1 area of ly as possible the distance observer-to-
etc. Maps can also provide information on 400 cm²). Two surveyors are necessary for colony. Then measure approximately the
gaps in survey effort in order to plan future this work. size of the colony, using the projected beam
work. Figure 53. Calculating the density of and the area of the torch, draw the form of the group and
General remark occupied by the bats. if necessary of the areas with different densi-
5.2.5 Surveyors and volunteer training In a cave the roof and the walls are rarely ties.
In France the majority of bat surveys rely flat and their relief is more or less strongly • Use a light colour wooden square frame • With binoculars estimate the different
on volunteers because universities are not marked. As the photograph does not take (internal size 20 cm x 20 cm) on top of a tele- densities of the colony and copy them out
interested in bat research at present. Volun- the third dimension into account, it is nec- scopic pole (3 m x 2). The camera will be on the drawing.
teers are members of the local bat groups, essary to establish relief classes which cor- a 24 mm x 36 mm reflex with changeable
they do not require any licence for count- lens.You need to be able to change the focal Processing the data
ing bats, including inside roosts. However length from 28 mm to 200 mm, so a zoom a) Using photographs
they must have undergone training and / or 1
An aliquot is a part contained in another number and lens is useful. It is also essential to use a • On a white sheet of paper show the slide
be accompanied by a licensed bat worker. dividing it without a remainder, an integral factor, e.g. film for slides and a powerful flash gun. of the 400 cm² frame. Count the number
2 is an aliquot part of 6.
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 EUROBATS Publication Series No. 5 Guidelines for Surveillance and Monitoring of European Bats

zone). Each group is assigned a number the peak frequency of its calls is on 50 kHz
that appears on the annual count form. and no overlap of the two species is to be
expected. The count of M. capaccinii will be
b) Using evaluation with torch beam fairly reliable (and is corroborated by the
• With reference to the field sketch, draw second surveyor).
the outlines of the colony on a squared • However, difficulties arise in presence
sheet of paper, using the measures esti- of M. myotis or M. blythii (peak frequency
mated with the torch beam to determine 30 kHz and it is then necessary to sepa-
the scale. rate visually M. capaccinii from the group
• You might have to outline the areas of M. myotis / blythii. In that case a subdued
different densities or relief that have been light will be used (a paraffin oil lamp or
observed in the field. a weak head-lamp) to see which bat is
• Proceed as above to calculate the surface which.
and the number of individuals. • This count will give the number of indi-
viduals in the cave during the parturition
5.2.8 Recommended surveillance method period.
for Myotis capaccinii
As part of the Action Plan for bats (Objec- b) Count of the young
tive 3) twelve maternity colonies of Myo- A quick count of newborn young can be
tis capaccinii were surveyed for five years tried only if the presence of people in the
Figure 54. Example of count sketch with the area covered by the different groups of Miniopterus schreib- (1999-2003) in three regions. They were the cave does not disturb them, and once the
ersii (in black the areas without bats). The numbers in bold show the full squares with the same density as most important roosts of the species. adults have left the roost.
in the reference frame on photographs. The figures in the incomplete squares correspond to the calculated
The period of survey was preferably Some characteristics of M. capaccinii
number of individuals (source: M. Barataud).
30 May – 10 June, i.e. starting about ten ecology allow this method, which had been
days after the first births (around 20 May). previously tested without any mortality:
of individuals in the square ticking every the colony, showing if necessary the areas • Parturition starts very early, generally
counted nose with a felt-tip pen. Multiply the with a different density and from the field Survey method from 20 May to the end of the month in
number by 25 to get the density of one m² or sketches the roof areas with a relief. a) Count of emerging bats most cases.
divide it by 400 for a density of one cm². • Count the full squares and multiply their • At least two observers are necessary for • The young of M. capaccinii are present
• On a vertical support, put a sheet of pa- true area (400 cm²) by the density per cm² the count. They have to sit in front of the before the young of other species, which do
per with a 1 / 10 grid (2 cm squares) or pref- that they can have. cave entrance(s) before the emergence of not give birth before the end of May or the
erably 1 / 20 grid (1 cm squares) – or several • Every incomplete square will be meas- the bats and note the time when the first beginning of June.
sheets according to the size of the colony. ured (according to the used scale) to deter- and the last individual leaves the roost. • Although we have little knowledge of
• Place the projector so that its beam is mine the surface covered by the bats, this • As Myotis capaccinii forms mixed mater- female behaviour during the first nights af-
perpendicular to the sheet of paper and ad- surface being simplified to show a triangle nity colonies with Miniopterus schreibersii ter giving birth, it seems that the females
just the distance in order that on the pro- or a quadrilateral.The obtained surfaces will and / or Myotis myotis / blythii it is necessary leave the young in the nursery when they
jected slide the ruler in front of the colony be multiplied by the corresponding densities to count the emerging bats with a bat de- are a few days old, under the supervision
measures 10 cm (1 / 10) or 5 cm (1 / 20). Each and their total added to the full squares. tector (Bat Box III or Petterson D200) set on of one adult or more. However, the females
square on the sheet represents the aliquot • All the information regarding the colony 35 kHz (peak frequency for M. capaccinii). go back and forth inside the cave network
area of 400 cm². should appear in the caption (densities of • If Miniopterus schreibersii is also present or even outside. But there is great variabili-
• Then draw on the sheet the outlines of individuals / m² and relief index for each in the site there should be no problem as ty in their behaviour which can be affected

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by the prevailing weather and some nights species. A survey of these clustering sites trends of many regional bat populations The efforts to develop a nation-wide sys-
they do not emerge at all. So caution is nec- could be done from 20 February to 10 March were well observed. Some of these regional tem for monitoring bat populations were
essary. and would cast a new light on the annual bat monitoring results had been document- oriented to the species and methods pre-
This count is therefore performed at cycle of M. capaccinii. ed in the National Reports which Germany viously recommended by the EUROBATS
night, once the adults have left the cave. The provided at the Sessions of the Meeting of Agreement. For the Greater mouse-eared
counting can start only when most of the 5.3 Germany the Parties of the EUROBATS Agreement in bat (Myotis myotis), an agreement of nature
colony has departed. A maximum of two 5.3.1 Introduction 2000, 2003 and 2006 (see http://www.EURO conservation authorities, NGOs and bat ex-
observers should be allowed in the cave to In Germany several bat monitoring pro- BATS.org/documents/national_reports. perts was reached calling for a nation-wide
compare their numbers and to shorten their grammes are ongoing at a regional level htm, section Germany). survey, using standardised methods, and
stay, as much as possible, as lactating fe- with special reference to the Federal States beginning with volunteer workers in 2003
males return rapidly to feed the young. of the country (Länder). However, in ac- 5.3.3 Surveillance of Greater mouse-eared and 2004 (BIEDERMANN et al. 2003).
The counting method is as follows: cordance with the EUROBATS Agreement bats
• Count the young as precisely as possible a standardised monitoring programme for Since 1996 the development of a standard Method
using binoculars (8 x 23) or a spotting scope particular species was developed by bat procedure for the surveillance and moni- Each year all adult animals are counted in
or using the projected area of the torch specialists from nature conservation au- toring of bats in Germany has been one of all suitable maternity roosts from mid-May
beam (use a powerful torch with a focus- thorities and NGOs and has been imple- the main tasks of the advisory body which to mid-June (before the young are born). In
sing beam which should project a clear ring mented for the Greater mouse-eared bat was established by the Federal States in ac- each case bats are counted either during
on a wall – if possible ring diameter of 1 m (Myotis myotis). In 2007 the German Federal cordance with Article III 5 of the EUROBATS the day in their roost or in the evening as
at 10 m distance). Government and the Federal States agreed Agreement. This body initiated a workshop they leave the roost. In addition, each year
• Observers should minimise the time upon a surveillance scheme for bats and on bat monitoring methods during the bi- juvenile bats (alive or dead) are counted in
spent in the roost. other species and habitats of conservation annual conference of bat conservation and all suitable roosts from the end of June until
This second count will reveal the number concern to fulfil monitoring obligations of research in May 2001 in Prenzlau hosted mid-July (before the young are able to fly).
of births for the year and hence the breed- the EU Habitats Directive. It is worth high- by the NGO Naturschutzbund Deutschland They should be counted either during the
ing success (but not the flight success). lighting this agreement as an extraordinary (NABU). Basic ideas relevant for a bat moni- day in the roost (especially where colonies
step forward to overcome the inconsistent toring programme were developed through are small) or at night after the adults have
Comments diversity of nature conservation measures various initiatives, including the research left the roost. In cases in which roost and
This survey method might possibly allow in Germany caused by the federal struc- and development project “Model for an exit counts are especially difficult surveyors
establishing a ratio between the number of ture. overall concept for monitoring of animal are urged to work in teams to improve data
emerging adults and the number of counted All bat surveillance and monitoring pro- species populations, illustrated with the ex- quality. Wherever possible a survey after a
neonates. This ratio would give an estimate grammes in Germany are mainly based on ample of avian fauna“ by the Federal Agen- rainy night should be avoided, since such
of newborn M. capaccinii (in normal partu- voluntary fieldwork. cy for Nature Conservation (BfN). In April conditions can encourage adults to remain
rition conditions) in sites with inaccessible 2002 the Federal Agency and the Society for in alternative roosts away from the materni-
spaces or where the cluster of newborns is 5.3.2 Regional bat monitoring Bat Conservation and Research in Thuringia ty colony. Additional population data from
not visible. programmes (IFT) carried out another workshop on the hibernation sites or other sources should
It shows that for regular parturition roosts Special regional data surveys have been Isle of Vilm, near Rügen, on “Steps toward also be taken into account.
of the species it is possible to perform pre- conducted at maternity roosts of certain nation-wide monitoring of bat populations“. In the two-year programme, 221 persons
cise counts of the maternity colony. species and in winter roosts of certain ar- This workshop highlighted the fact that participated and surveyed Myotis myotis at
In Languedoc-Roussillon adults of both eas of Federal States. As each state has set special coordination offices for bat conser- 799 maternity roosts. They provided about
sexes gather at the end of winter (Februa- its own surveillance standards and meth- vation are needed in all Federal States to 7,400 data sets on the species and gave a
ry) and are grouped together in the same ods, collation of data on a national level is collect and evaluate survey data and main- very good overview on the species' status
roosting places without mixing with other usually inadequate. However, numbers and tain surveillance standards. in Germany. The survey also showed that

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successful bat surveillance can be based on Then the Federal Agency commissioned exhaustively surveyed (total census). As direct and indirect measures can be applied
volunteer contributions. However, it became two consultants (PAN and ILÖK) to devel- an area of occurrence in bats a square of to minimise efforts as far as possible. Meth-
clear that professional coordination, guid- op a surveillance scheme based on the re- the German national topographic network ods vary from counting individuals, colo-
ance, and reporting are necessary to keep sults of the administrative working group 1:25,000 (TK25) was taken. nies, maternity roosts, areas of occurrence
things going. Many participants continued as well as the expertise of bat experts (e.g. The agreed concept of the surveillance and TK25 grid squares where a certain spe-
to survey maternity roosts annually in the DENSE & MAYER 2001, BIEDERMANN et al. 2003, programme further outlines which param- cies is present. All records from a report pe-
standardised way and NABU took over the PETERSEN et al. 2004, DIETZ & SIMON 2005). eters shall be used to indicate the trend of riod are considered for this assessment.
responsibility for further data compilation. The targets of the consultants' proposals a population, its structure, the total popula- To assure good data quality and detect
were to fulfil the legal requirements of the tion size of the species, and the occurrence changes in species' ranges nature conser-
5.3.4 German federal surveillance and Habitats Directive at the national level and of suitable habitats for the species (Table vation agencies of the Federal States are
monitoring of bats under the to minimise time efforts and expenses at 6). For most species two recordings (every asked to continuously gather data on the
Habitats Directive the regional level of the Federal States. The three years) are proposed per report period occurrence of bats apart from the samples
In accordance with Articles 11 and 17 of the recommended surveillance and monitor- with two surveys in each recording year. For which are necessary to assess population
EU Habitats Directive each Member State ing schemes were finally evaluated by the Barbastellus barbastellus, Eptesicus nilsso- size and trend. An estimation of the size of
of the European Union has to report on the federal and state ministries for nature con- nii, Myotis emarginatus and Plecotus aus- suitable habitat is important to report about
conservation status of species listed in the servation and their technical advisors. The triacus the rhythm should be increased to the habitat provided for the species and the
Annexes of the Directive every six years. Federal States adopted the proposal and three recordings (every two years) per pe- percentage actually occupied. As it is al-
An appropriate surveillance and monitor- promised to provide the data needed for a riod. Rhinolophus ferrumequinum should most impossible to state habitat size exact-
ing system has to be applied in all biogeo- national conservation status assessment in be recorded every year to watch carefully ly, it is only estimated from the number of
graphic regions within a Member State. In the German part of the Atlantic and Conti- this critically endangered species. TK25 grid squares where suitable habitats
Germany, due to the federal structure of the nental biogeographic region. The German The population trend of bats can be as- are present.
state, implementation of the Habitats Direc- area of the Alpine biogeographic region is sessed either by counting the number of As the Federal States cover different
tive is the responsibility of the 16 Federal covered by the federal state of Bavaria. animals at a hibernation site, the number of parts of the three biogeographic regions,
States (Länder). As there was no standard- A central idea of the consultants' pro- females in maternity roosts or the assessed the 63 samples per region were shared in
ised national surveillance and monitoring posal is that common species and habitats number of adult females in the surveyed accordance with the distribution and occur-
programme of species and habitats in prac- should be surveyed at sample sites of occur- area of occurrence. A declining population rence of each species. Federal States that
tice, the Federal Government took the initia- rence which should be chosen by the Fed- trend exceeding 1% per annum is automati- host a major part of the total population of a
tive to develop one which was appropriate eral States. To assure representativeness cally assessed as an unfavourable conser- species have to take more survey samples
for EU reporting procedures. This included in a statistical sense it should be a random vation status. However, in some bat species than others (Table 7). However, the results
the bat species occurring in Germany be- sample. Within the Directive's framework of appropriate methods to survey population of this federal surveillance scheme with 63
cause all European bats are listed on Annex a six-year reporting period and an overall trends are still under discussion and may samples will only refer to the whole area of
IV of the Directive, some are even listed on assessment result within three categories be modified (e.g. Myotis bechsteinii). the particular biogeographic region in Ger-
Annex II. (traffic light scheme: Favourable = green, Information on population structure is many. If a federal state wishes to assess a
As a first step the Federal Agency for Unfavourable – Inadequate = amber, Unfa- not compulsory for assessing conservation species' conservation status within its re-
Nature Conservation (BfN) chaired a work- vourable – Bad = red) the consultants found status. Therefore, from the viewpoint of na- gional borders it should survey a total of 63
ing group of representatives from nature a sample size of 63 per biogeographic re- tional reporting duties under the Habitats samples there to get consistent and reliable
conservation authorities of the Federal gion as the statistic threshold value to rec- Directive, population structure should only results. Apart from that, it should be kept in
States, which elaborated detailed propos- ognise ongoing population trends. Species be surveyed if it does not mean additional mind that monitoring under Article 11 of the
als for species surveillance and assess- with less than 63 areas of occurrence which work, if it can be done without disturbance Habitats Directive provides an overview.
ment procedures in accordance with the can be sampled within a biogeographic re- and if it is necessary from a scientific point For management and planning purposes
Habitats Directive (SCHNITTER et al. 2006). gion are classified as rare and should be of view. To assess the total population size additional case-specific monitoring at the

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local scale is necessary or even a legal ob- Special rules and algorithms were devel- Table 6 (cont.)
ligation. oped and applied. Finally the status of all
Areas of Total popula-
For the 2007 report in accordance with species and habitats of each biogeographic Species Region occur- Survey method
Population trend Population
tion size
Size of
(number of) structure habitat
Article 17 of the Habitats Directive, repre- region were approved by a ministerial con- rence (number of)

sentatives from the federal and state min- ference before the result was sent to the EU. ATL 63 exhaustive survey
adult females in proportion of re-
istries for nature conservation and their A similar procedure will be implemented Myotis myotis CON 1,680 sample
maternity roosts productive females
maternity roosts

technical advisors agreed on a procedure for the next report based on the data cur- ALP 22 exhaustive survey

to aggregate and evaluate relevant data in rently provided by the German federal sur- ATL 55 exhaustive survey
adult females in
order to assess the conservation status of veillance and monitoring programme from Myotis mystacinus CON 956 sample
maternity roosts
maternity roosts

species and habitats following the traffic the year 2008 onwards. ALP 23 exhaustive survey
ATL 140 exhaustive survey number of
light scheme of the European Commission. occupied TK25
animals in hiber-
Myotis nattereri CON 1,420 sample maternity roosts grid squares
nation sites
Table 6. Surveillance concept for bat species in the biogeographic regions of Germany (status: May 2008). ALP 7 exhaustive survey

Regions: ATL = Atlantic biogeographical region, CON = Continental biogeographic region, ALP = Alpine ATL 85 exhaustive survey adult females in
Nyctalus leisleri maternity roosts
biogeographical region. CON 533 exhaustive survey maternity roosts
dd = data deficient
ATL 227 exhaustive survey
adult females in proportion of re-
Areas of Total popula- Nyctalus noctula CON 1,285 exhaustive survey roost sites
Population trend Population Size of maternity roosts productive females
Species Region occur- Survey method tion size
(number of) structure habitat ALP 2 exhaustive survey
rence (number of)
ATL 9 exhaustive survey assessment
adult females in adult females in occupied TK25
Pipistrellus kuhlii CON 10 exhaustive survey procedure not yet
Barbastella animals per maternity roosts maternity roosts grid quarters
CON 561 sample occurrences defined
barbastellus hibernation site
ALP 7 exhaustive survey ATL 139 exhaustive survey
adult females in a roost sites
proportion of re-
ATL 1 exhaustive survey Pipistrellus nathusii CON 824 exhaustive survey defined monitoring
productive females
adult females in area
Eptesicus nilsonii CON 311 exhaustive survey occurrences ALP 10 exhaustive survey
maternity roosts
ALP 19 exhaustive survey ATL 286 sample
adult females in a
Pipistrellus proportion of re-
ATL 244 sample CON 1,554 sample defined monitoring maternity roosts
pipistrellus productive females
adult females in area
Eptesicus serotinus CON 1,081 sample colonies ALP 30 sample
maternity roosts number of
ALP 4 exhaustive survey ATL 6 exhaustive survey adult females in a assessment occupied TK25
Pipistrellus
defined monitoring procedure not yet roost sites grid squares
Myotis alcathoe CON dd exhaustive survey pygmaeus CON 243 exhaustive survey area defined
ATL 24 exhaustive survey ATL 200 sample
adult females in a number of
occupied TK25 animals in hiber-
Myotis bechsteinii CON 717 sample defined monitoring occupied TK25 Plecotus auritus CON 1,679 sample maternity roosts
grid squares nation sites
area grid squares
ALP 1 exhaustive survey ALP 15 exhaustive survey
ATL 45 exhaustive survey ATL 20 exhaustive survey adult females in proportion of re-
adult females in Plecotus austriacus maternity roosts
Myotis brandtii CON 565 exhaustive survey maternity roosts CON 776 sample maternity roosts productive females
maternity roosts
ALP 11 exhaustive survey Rhinolophus adult females in proportion of re- adult females in
CON 31 exhaustive survey number of
ATL 64 exhaustive survey maternity roosts ferrumequinum maternity roosts productive females maternity roosts
animals in hiber- occupied TK25
Myotis dasycneme or hibernation Rhinolophus adult females in proportion of re- adult females in
CON 153 exhaustive survey nation sites CON 79 exhaustive survey grid quarters
sites hipposideros maternity roosts productive females maternity roosts
ATL 219 exhaustive survey ATL 33 exhaustive survey
animals in hiber- number of
Myotis daubentonii CON 1,615 sample roost sites average adult proportion of re-
nation sites Vespertilio murinus CON 470 exhaustive survey records occupied TK25
animals per roost productive females
ALP 18 exhaustive survey grid squares
ALP 7 exhaustive survey
CON dd exhaustive survey adult females in proportion of re- adult females in
Myotis emarginatus
ALP 6 exhaustive survey maternity roosts productive females maternity roosts

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Table 7. Number of bat survey samples per Federal State for the German federal surveillance and monitor- chalk mines in the south. In 1986, these be combined and standardised to form a
ing programme. counts were formed into a monitoring new monitoring scheme. The pilot was suc-
Regions: ATL = Atlantic biogeographical region, CON = Continental biogeographic region. All samples of scheme, which is now coordinated by the cessful: the data already gathered were of
the Alpine biogeographic (ALP) region lie within Bavaria and are therefore not separately listed in the table. Dutch Mammal Society (VZZ), and the good quality, and the volunteers were will-
Federal States: BB = Brandenburg, BE = Berlin, BW = Baden-Württemberg, BY = Bavaria, HB = Bremen, number of counted sites increased. Mines ing to add the data already gathered in past
HE = Hesse, HH = Hamburg, MV = Mecklenburg-Western Pomerania, NI = Lower Saxony, NW = North- are still counted, but now volunteers also years to the scheme. 2008 was the first “of-
rhine-Westphalia, RP = Rhineland-Palatinate, SH = Schleswig-Holstein, SL = Saarland, SN = Saxony, ST =
visit bunkers, fortresses, ice cellars, old ficial” counting year. A handbook and iden-
Saxony-Anhalt, TH = Thuringia.
brick kilns, castle cellars and even bridge tification guide were printed, forms and a
Species Region BB BE BW BY HB HE HH MV NI NW RP SH SL SN ST TH pillars. Currently about 1,100 sites are database were designed. A course on the
Barbastella counted yearly. method and on species identification was
CON 10 4 20 3 3 1 3 7 4 8
barbastellus developed and is given to new volunteers.
Eptesicus ATL 1 34 16 10 2 Method The scheme focuses on Plecotus aus-
serotinus CON 12 8 10 4 4 1 4 1 2 1 7 4 5 In October, the monitoring coordinator of triacus and Myotis emarginatus. Of the
Myotis bechsteinii CON 2 10 16 10 1 3 9 1 2 2 7 VZZ sends site lists, forms, and a permit to latter, all known breeding females (i.e. the
Myotis
CON 6 2 8 14 5 6 2 3 4 2 1 4 2 4
visit the hibernacula to all volunteers. Vol- two known breeding colonies) are counted.
daubentonii
unteers visit their site once between 15 De- For this reason, the scheme now focuses
Myotis myotis CON 5 9 18 6 2 2 4 6 1 4 1 5
cember and 15 February, counting all bats on the counties of Zeeland, Noord-Brabant
Myotis visible using LED torches. Forms are filled and Limburg, where these species occur. In
CON 5 9 17 5 1 3 5 3 1 5 3 6
mystacinus
in and sent to the provincial coordinator. the next three years, the scheme will be ex-
Myotis natteri CON 6 1 7 14 5 6 2 3 4 2 4 4 5
He or she checks the forms for errors and panded to include the whole of the Nether-
Pipistrellus ATL 1 34 18 8 2
then sends them to the monitoring coor- lands, so that data on other species living in
pipistrellus CON 6 8 15 5 6 2 3 4 1 1 4 4 4
dinator at VZZ. Here, data are entered into attics can be gathered.
ATL 1 36 18 6 2
Plecotus auritus a database, a number of additional error
CON 7 2 8 13 5 5 2 3 4 2 1 4 4 3
checks are performed, and the data are sent 5.4.4 Car transect monitoring
Plecotus
austriacus
CON 5 11 19 6 2 6 7 7 to Statistics Netherlands (CBS). Indices are In 2007 a car transect monitoring scheme
calculated, then placed on the CBS website was piloted (DEKKER et al. 2007). This pilot
http://statline.cbs.nl/statweb (in Dutch) and consisted of driving ten transects, testing
5.4 Netherlands For bats, there is one long-running scheme presented to the Dutch government. VZZ the method and technique and finding the
5.4.1 Introduction for hibernacula counts, and two summer gives feedback of the results to volunteers. detection frequencies of target species.
Biodiversity in the Netherlands is moni- schemes that have recently been started: Volunteers are actively stimulated to The pilot was repeated in 2008 with aims
tored through the Network Ecological Mon- car surveys and counts of colonies in attics. keep visiting “disappointing” sites. Training to increase the number of transects, test a
itoring (NEM) programme, which is funded There are also a number of other initiatives is organised by VZZ, which involves train- number of improvements in the setup used
by the Dutch Government. Partners in this underway including a new Dutch mammal ing of new volunteers during counts and in 2007, and calculate inter-transect varia-
programme are, amongst others, the NGOs atlas project, which will involve training and provision of identification workshops by a tion in number of bats encountered.
that gather the data and CBS (Statistics facilitating volunteers, and collation and val- number of workgroups.
Netherlands) which calculates indices and idation of bat distribution data. Method
trends and checks the quality of the data. 5.4.3 Attic colony counts Transects are driven at 20-30 km / hour with
Analyses are done using TRIM, a loglinear 5.4.2 Hibernacula counts For a number of years, bat workers have an Anabat detector on the roof of the car,
GLM adapted and implemented for ecologi- Hibernacula counts in the Netherlands have counted bats in attics of churches and ab- and with a hand held computer (PDA) with
cal time series (VAN STRIEN et al. 2004; freely been performed since the 1940s. In the ear- beys. In 2007 a pilot study was carried out a Global Positioning System (GPS) logging
downloadable from www.cbs.nl). ly years, they were almost only done in the by VZZ and CBS to see if these counts could the route. Sounds are analysed by a profes-

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sional of VZZ. As Anabat timestamps the re- The car transects and attic counts will be Annual counts of bats in bat boxes have associations. An evaluation of the develop-
cordings, the record of bats and position of planned so that they also provide summer been carried out, in some cases over long ment of the programme since its inception
the car can be pinpointed to create maps. distribution maps, on a 10 x 10 km grid pre- time periods. This yields mostly informa- was published by RODRIGUES et al. (2003).
The resulting database of information is cision. tion on P. nathusii. No trend analyses have Cave-dwelling species are considered
sent to CBS for analysis. A newsletter is published twice a year yet been performed with these data. to be those that regularly hibernate and / or
for all VZZ volunteers on the results of the There has been much swarming re- breed in underground roosts: Minio-
5.4.5 Species coverage monitoring programme. search in the past few years. In 2001 a first pterus schreibersii, Myotis myotis, M. bly-
The three schemes aim to cover all Dutch workshop was held to train people in mist- thii, M. nattereri, M. emarginatus, Rhino-
bat species (see Table 8). Myotis mystaci- 5.4.6 Other initiatives netting (SPOELSTRA 2006), as there was little lophus ferrumequinum, R. hipposideros,
nus and M. brandtii can only be distin- Apart from these schemes, there are a experience with mist-netting in the Neth- R. euryale and R. mehelyi. In addition, sev-
guished in the hand, and VZZ considers it number of initiatives that are not (yet) part erlands. In 2006 and 2007, workshops were en other species are occasionally found
unethical to disturb animals during hiber- of the NEM programme: a study focused again given, resulting in a pool of experi- in this type of roost: Myotis bechsteinii,
nation, so these species are included to- on Myotis dasycneme, counts of bats in bat enced volunteers (DEKKER & LIMPENS 2007). At M. mystacinus, M. daubentonii, Eptesicus
gether. However, a study in which a number boxes, and swarming studies. these workshops, a number of species, such serotinus, Plecotus auritus, P. austriacus
of animals were identified in the hand A large study on Myotis dasycneme is as Myotis bechsteinii and Myotis brandtii and Barbastella barbastellus.
during mistnet counts, and examination underway to provide detailed information were caught in numbers higher than are
of dead or awake animals in hibernacula on roost counts, capture-mark-recapture found at hibernacula counts. 5.5.2 Surveying hibernacula
showed that M. brandtii is rare: only 1.7% control of pond bats in summer, spring and Following these surveys, a monitoring Monitoring of 43 roosts known to be of na-
of the M. mystacinus / brandtii that were autumn and control of marked animals in study has been set up under the umbrella tional importance (criteria defined by PAL-
checked were in fact M. brandtii (MOSTERD et winter. of VZZ with the support of a large pool of MEIRIM & RODRIGUES 1993, under revision) is

al. 2005). volunteers. In this study, swarming animals carried out annually between the beginning
are identified by mist-netting one night at of January and 15 February. Observations
six selected chalk mines every three weeks. are made inside the roosts, counting the
Table 8. Coverage of the National Ecological Monitoring programme’s bat monitoring scheme.
The aim is to learn more about the tempo- individuals or estimating the area of the
1
Only 350 individuals counted, population estimated to be ~10,000 individuals.
ral and spatial dynamics of the number of colonies (visually and with photographs).
2
Only a few individuals counted.
individuals and species that are swarming Temperature and relative humidity are
Species Hibernacula Car transects Attics at such sites. This data will be compared measured.
Plecotus auritus X with counts of hibernating species at these
Plecotus austriacus X
sites. 5.5.3 Surveying summer roosts
Myotis mystacinus / brandtii X
There are two maternity seasons: April / May
5.5 Portugal for M. myotis and June / July for the other
Myotis nattereri X
5.5.1 Introduction cave-dwelling species. As a result, 52 vis-
Myotis emarginatus X X
In Portugal, a monitoring programme of its to roosts considered of national impor-
Myotis dasycneme (X) 1
X ?
cave-dwelling species has been in progress tance (17 for M. myotis and 35 for other spe-
Myotis myotis X
since 1987, coordinated by the “Instituto da cies) are carried out annually. This number
Myotis daubentonii (X) X
Conservação da Natureza e da Biodiversi- includes underground roosts and some
Myotis bechsteinii (X) 2
dade” (ICNB). The programme involves the buildings that harbour important colonies
Nyctalus noctula X
annual estimation of bat numbers present in of R. ferrumequinum and R. hipposideros.
Eptesicus serotinus X
the most important wintering and maternity Observations are made inside the roosts,
Pipistrellus nathusii X
roosts. Data are collected by ICNB, “Facul- counting the individuals or estimating the
Pipistrellus pipistrellus X dade de Ciências de Lisboa” and speleology area of the colonies (visually and with pho-

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tographs). Temperature and relative humi- • Non-cave dwelling bats: Myotis dauben- tocols which also deal with an estimation of The NBMP datasets offer a unique opportu-
dity are measured. Methods described for tonii, Eptesicus serotinus, Pipistrellus the quality of bat habitat were made. nity to examine the quality of data collected
Myotis myotis / blythii and Miniopterus pipistrellus / pygmaeus, Nyctalus noctu- A lack of suitable data prevented an esti- in different surveys, because some species
schreibersii in the EUROBATS Resolution la; mation of population size at the start of the are surveyed using more than one method.
2.2 are used. It is believed that these meth- • Species that have priority for further monitoring for the majority of proposed sites However, at present there are no long-term
ods can be successfully applied to R. eury- observations and research: Pipistrellus and consequently for the whole scheme for datasets (> 20 years) that allow a compari-
ale, R. mehelyi, M. myotis, M. blythii and nathusii, Barbastella barbastellus, Myotis particular species. An additional problem son of population trends between different
M. schreibersii that are very faithful to their dasycneme. is that some areas of Slovenia still lack the surveillance methods for the same bat spe-
roosts and hang from the ceiling, making Monitoring is carried out throughout Roma- data required to propose an adequate grid cies. Longer time-series are required before
the observations very reliable. More prob- nia in 35 underground sites (Eastern Car- of monitoring sites covering particular spe- robust analyses can be initiated.
lems occur in the case of R. ferrumequinum pathians 3 caves, Western Carpathians 15 cies distribution. Therefore, intensive con- Based on the theoretical grounds dis-
and R. hipposideros since they use many caves, Southern Carpathians 17 caves). tinuous monitoring of proposed sites and cussed above, where species are covered
roosts to breed in small numbers. In the To implement the NBMPR it has been additional bat surveys are necessary. in more than one survey, priority is given
case of M. nattereri and M. emarginatus, necessary to develop and maintain a net- The Ministry has approved the proposal to population trend results in the following
only maternity colonies in underground work of volunteers covering all regions of for a monitoring scheme and the work is order:
roosts are known, but since they normally Romania. Volunteers have been recruited progressing. 1. Waterways survey and Field survey
use hidden places (especially M. nattereri) through talks to university students, spe- 2. Hibernation survey
very often the colonies cannot be observed. leological clubs, environmental protection 5.8 United Kingdom 3. Colony counts
Frequently, only the capture of flying juve- agencies, environmental NGOs and Nation- 5.8.1 Introduction
niles enables the identification of maternity al Parks. Bat identification skills have been The UK National Bat Monitoring Programme 5.8.2 Waterway survey
sites. increased through training, workshops and (NBMP) is designed to collect population The waterway survey began in 1997 with
field work participation. trend information for bat species resident a successful pilot and surveys have con-
5.6 Romania in the UK. It is run by the Bat Conservation tinued annually. It focuses on Myotis dau-
The National Bat Monitoring Programme 5.7 Slovenia Trust (BCT), a non-governmental organisa- bentonii along water courses (such as riv-
in Romania (NBMPR) commenced in In 2006, the Ministry of the Environment and tion (NGO), in partnership with the Joint ers and streams, but excluding lakes and
2002. This Programme is modelled on the Spatial Planning of the Republic of Slov- Nature Conservation Committee (WALSH ponds) as this species has a high depend-
UK's National Bat Monitoring Programme enia commissioned a study on monitoring et al. 2001, BATTERSBY 2005). The NBMP was ence on water bodies for foraging and the
(NBMPUK). Two principal methods have all bats species present in Slovenia. The established in 1996 as a pilot programme ease of identifying this species fits in well
been applied in Romania: observations at Centre for Cartography of Fauna and Flora to test the methods being used and contin- with mass participation surveys.
summer maternity roost sites and winter (PRESETNIK et al. 2007) judged that based ued as a pilot until 2000, when it became The Environment Agency (EA), through
hibernation sites in underground habitats. on field data eight bat species were suit- an established long-term surveillance pro- its River Habitat Survey (RHS), has surveyed
Surveys occur twice in the hibernation pe- able for monitoring by hibernation counts gramme. over 10,000 random stretches of waterway
riod (December-February) and twice in the and 63 sites (mostly caves) were chosen. A sampling approach is used on all sur- for a variety of habitat features including
summer period (May-July). The data are The monitoring of 371 selected maternity veys with the assumption that trends occur- flow rate and bankside vegetation. The BCT
collated in a standard datasheet. roosts (mostly churches) is expected to ring in sample sites reflect trends occurring has worked closely with the EA since 1998
Selected key species and categories for give a good insight into the conservation in the general population. Theoretically, this and, where possible, surveyed existing RHS
monitoring include: status of twelve bat species. 13 bat species assumption is strongest when sample sites sites for M. daubentonii. This approach
• Cave dwelling bats: Rhinolophus ferrum- could be monitored by 24 ultrasound detec- are chosen at random; random surveys are adds value to the dataset because it ena-
equinum, Rhinolophus hipposideros, tor transect counts. Mist-netting at 20 pro- considered to be more robust and repre- bles cross analysis of both datasets.
Myotis myotis / blythii, Miniopterus posed sites could provide information on 14 sentative of the total population than sur-
schreibersii; bat species. In total, 467 detailed field pro- veys using self-selected samples.

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Method us for two minutes, then re-tune their detec- Unlike colony counts, the hibernation sur- measure of the rate that new colonies are
Data are collected in a simple, repeatable tor and listen for N. noctula and E. serotinus vey monitors potential sites as species can established or their effect on population
fashion at a random selection of courses bats whilst walking to the next stopping move into almost any existing site where trends. Little is known about the extent of
throughout the UK. Where possible, survey- point. The survey starts at twenty minutes they have never been recorded previously. new colony establishment so it is difficult to
ors are assigned a random 1 km stretch of post sunset. assess the magnitude of the issue.
water body that lies on an existing RHS site Trends derived from field surveys are 5.8.5 Colony counts One way of assessing the potential im-
and that is within 10 km of the surveyor's considered to provide the most robust Colony counts are a traditional method for portance of new colony formation or colony
home address. trend data. Volunteers are assigned ran- monitoring the status of roosts. For each mobility in general on species population
Surveyors make a day visit to secure dom sites across the UK and the random species, information can be used to make trends would be to look at roost site age.
landowner permission and to assess the site selection process includes sites where the an assessment of the importance of the For example, if a species is recorded using
for safety. They mark out ten points along species of interest may not occur at present roost at the national, regional and local lev- new buildings (new roosts) then this would
the 1 km stretch, approximately 100 m apart. but has the potential to do so in the future. el through collation and analysis of data. provide evidence of colonies (or parts of
On two evenings in August they stand at This provides a means of assessing change The relationship between trends in spe- colonies) switching from existing roosts. If
each of the ten points for four minutes, re- in distribution as a result of population ex- cies' colony size and population trends has new sites are often used by a species then it
cording M. daubentonii activity with a hete- pansion as well as change in relative abun- not been established but, over time, com- could indicate that interpreting population
rodyne detector, using a torch to confirm the dance. There are potential problems with parison of field and colony trends may pro- trends from counts at existing roosts only is
bat is flying close to the water surface (be- volunteers using different types of electron- vide an answer. For the present, where trend not robust. Species such as R. hipposideros
haviour characteristic of M. daubentonii). ic equipment over time, volunteer turnover direction conflicts between field and colony are assumed to form new roosts only oc-
and volunteer experience, but these can be counts for the same species, the trend de- casionally (because they have very specific
5.8.3 Field survey included as covariates in the data analysis rived from field surveys will be considered roost requirements); therefore the chances
This survey began in 1998 and provides to assess effects on the results. most robust. of possible erroneous trends derived from
data on four species – Pipistrellus pipistrel- colony counts may not be as high as other
lus, Pipistrellus pygmaeus, Nyctalus noc- 5.8.4 Hibernation survey Method species with less stringent roost require-
tula and Eptesicus serotinus. A range of bat species aggregate at a va- Survey protocols for each species are simi- ments such as Pipistrellus species.
riety of hibernation sites during the winter lar although there are some minor inter-
Method months and it is possible to make annual species differences (related to differences 5.8.6 Survey coverage
Data are collected in a simple, repeatable counts of the number of bats encountered. in emergence times of species). Roosts are The total site network for the NBMP was
fashion in 1 km squares, drawn from a pool Bats are vulnerable to disturbance when self-selected by volunteers who make two 3,906 sites in 2006 and continues to grow
of 5,000 randomly generated 1 km² dis- hibernating and surveyors require training counts of bats emerging from the roost be- annually. Statistical analysis of past survey
tributed throughout the UK using National and a licence from the relevant UK Statutory tween late May and the end of June. A sum- data has shown that a sample size of at least
Grid References. Volunteers are assigned Nature Conservation Organisations (SNCO) mary of species surveyed on the project is 40 sites with presence of bats is required
a square at random within 10 km of their before entering sites. However, unlicensed shown in Table 9. to provide robust population trends for the
home address. Within each square a tri- surveyors can accompany licensed survey- Colony counts are restricted to where the UK (BCT 2001). Where species have been
angular “ideal” transect containing twelve ors into sites. species of interest is known to occur: no po- encountered on less than 40 sites trend
marked stopping points is overlaid. Survey- tential sites are monitored (i.e. sites where a analysis confidence is reduced due to low
ors make a day visit to secure landowner Method colony is not present but could be in future). precision associated with small samples.
permission and assess the site for safety. Sites are self-selected by volunteers who Colony counts are likely to be effective for For 11 of the 16 UK resident species there is
On two evenings in July they walk the make two counts, one in January and one monitoring population change only if it is sufficient coverage to carry out robust sta-
transect with heterodyne ultrasonic detec- in February. Counts are made of all spe- rare for new colonies to be established. This tistical analysis and this is shown below in
tors. At each of the twelve stopping points cies encountered and site details are also is because sampling only known roosts and Table 9.
they listen for P. pipistrellus and P. pygmae- recorded. not all potential roosts means there is no

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Table 9. Coverage of UK bat species with each monitoring method. database and population trend data and in- General Additive Models (GAM) calculate
A = encountered on > 40 sites; B = encountered on 10-40 sites; C = encountered on <10 sites. formation about the monitoring programme individual trends over time for each site sur-
Species Colony Counts Field & Waterway Survey Hibernation Survey
are made available through the NBMP an- veyed. They then amalgamate trends from
nual reports, published on the BCT website. all sites to produce an overall estimation
Barbastella barbastellus C
of trend direction with confidence limits.
Eptesicus serotinus A A
5.8.8 Volunteer training On the graphs in each survey description,
Myotis bechsteinii C
Volunteer training has always been a key crosses represent the calculated means
Myotis brandtii B
feature of the NBMP. Each year a series of (converted to Index) and the line represents
M. brandtii / mystacinus A
detector workshops is organised across the the estimated trend from the GAM. Dotted
Myotis daubentonii A A
UK. At workshops volunteers learn about lines represent confidence limits. The ac-
Myotis mystacinus B
the basic elements of bat sounds, how to tual trend occurring can be described from
Myotis nattereri A A
use their own hearing in order to discrimi- either the GAM (line) or the log-linear gen-
Pipistrellus nathusii
nate between the various species and how eralised model (crosses) although in many
Pipistrellus pipistrellus A A to use bat detectors as tools to help identify cases the interpretation is similar.
Pipistrellus pygmaeus A A bat sounds in the field. The workshops also The annual percentage change assumes
Nyctalus leisleri teach volunteers how to take part in vari- the annual trend direction is constant. It is
Nyctalus noctula A ous surveys with an opportunity to go on a estimated by calculating the annual percent-
Plecotus auritus A field session to polish up existing or practice age change that would take the population
Plecotus austriacus new found skills. They also ensure there is from 100 in the base year to the index value
Rhinolophus ferrumequinum A standardisation for field surveys and recruit in 2003.
Rhinolophus hipposideros A A new volunteers to the programme. On aver- The benchmark for monitoring sensitivity
age 15 workshops are held annually across is that sufficient sites are monitored to de-
the UK with over 300 participants receiving tect as a minimum population change of 50%
The difficulty in differentiating the two Field volunteers tend to be more experi- training. over 25 years, equivalent to the Red Alert de-
closely related Myotis species, M. mystaci- enced local bat group members as some clines for UK birds (GREGORY et al. 2002) and
nus and M. brandtii, means that the data skill with a bat detector is required. For the 5.8.9 Data analysis hopefully the more sensitive measure of 25%
for these two species has been pooled for Hibernation Survey volunteers require a li- The purpose of analysis is to draw correct over 25 years, equivalent to the Amber Alert
trend analysis and the trends assumed to cense from the relevant UK Statutory Nature conclusions on trends occurring in popula- decline for UK birds.
be the same for both species. Conservation Organisation before they can tions of interest. There are many factors that Power analyses carried out in 2002
survey sites and undergo extensive train- can influence trends (outside the population showed that if a minimum of 20 sites is moni-
5.8.7 The surveyors ing before being awarded such a licence. trends themselves) and the magnitude of tored annually (in the pattern of returned data
One of the most important aspects of the Unlicensed volunteers can enter hiberna- their effect should be estimated and methods from previous years, i.e. a mixture of new
NBMP is the participation of the general tion sites if accompanied by a licensed bat for reducing their influence put into place. sites and sites surveyed in previous years)
public as volunteer surveyors. Volunteers worker. Annual means for each project are calcu- then monitoring sensitivity is sufficient to
are the bedrock of the NBMP and come Volunteers invest a tremendous amount lated from a log-linear generalised model. identify UK declines of Red Alert magnitude
from a variety of backgrounds. Many colony of time and effort in the NBMP. Over 2,000 The model includes terms for factors that for all surveys and Amber alert declines for
counters are householders who happen to volunteers have surveyed over 3,000 roost could influence the means e.g. bat detector the hibernation survey. A minimum of just
play host to “their” colony. Participation re- and field sites since the programme be- make, temperature etc., so their effect can under 100 sites would be sufficient to iden-
quires little previous bat experience and the gan. On average over 730 volunteers take be measured. For easier interpretation the tify UK declines of Amber Alert magnitude
project enables them to learn more about, part every year with over 1,400 sites being means are then converted to an Index that for the field surveys. Power analysis has not
and value, “their” colony. surveyed. Data are stored in a centralised starts at 100 for the first reliable year of data. been carried out on the Colony Counts.

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trasound detectors for bat studies in ship, Peterborough. neme (Chiroptera: Vespertilionidae). den zur Erfassung von Arten der An-
Europe. Experiences from field identi- BCT (BAT CONSERVATION TRUST) (2001): The UK's Journal of Zoology, London, 241: 503- hänge IV und V der Fauna-Flora-Habitat-
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Chiropterologica, 1: 137-150. Final Report 2001. BCT, London. BROSSET, A. (1978): Les chauves-souris dis- Vielfalt 20, Bonn: 318-372.
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12: 47-56. BCT (BAT CONSERVATION TRUST) (2007): The Na- GIER, H. SALVAYRE & Y. TUPINIER (1988): La on the emergence behaviour of Pipi-
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BARATAUD, M. & P. JOURDE (1999): Les minio- Nyctalus noctula (Chiroptera, Vespertil- NEMANN, P. SALM & E. SCHRÖDER (eds.): FENTON, M.B. (2001): Bats: revised edition.
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BARLOW, K. (1999): Expedition field tech- malia, 68: 329-336. 42, Bonn: 192-203. P.J. TAYLOR & E. WHITE (2004): Individual
niques: Bats. Expedition Advisory Cen- BLOHM, T. (2003): Ansiedlungsverhalten, DEKKER, J.J.A. & H.J.G.A. LIMPENS (2007): In- signatures in the frequency-modulated
tre of the Royal Geographical Society, Quartier- und Raumnutzung des Abend- haalslag Verspreidingsonderzoek Ned- sweep calls of African large-eared, free-
London. seglers, Nyctalus noctula, in der Ucker- erlandse Zoogdieren VONZ 2006, Deel tailed bats Otomops martiensseni (Chi-
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ROS, J. (2002): Le statut du Grand rhinolophe Empfehlungen für die Erfassung und TMP & NBN (TRACKING MAMMALS PARTNERSHIP United States and territories: Problems
en France. Symbioses, 6: 33-34. Bewertung von Arten als Basis für das AND NATIONAL BIODIVERSITY NETWORK) (2004): and prospects. United States Depart-
ROUÉ, S. & GROUPE CHIROPTÈRES SFEPM (1997): Monitoring nach Artikel 11 und 17 der Engaging with Volunteers: Setting up ment of Interior, Geological Survey, Fort
Les chauves-souris disparaissent-elles? FFH-Richtlinie in Deutschland. Berichte and managing volunteer networks. Joint Collins, Colorado, 103-117.
Vingt ans après. Arvicola, 9: 19-24. des Landesamtes für Umweltschutz Nature Conservation Committee, Peter-
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7 List of contributors Other experts contributing information and advice:

John Altringham (United Kingdom) Tomasz Kokurewicz (Poland)

These guidelines were compiled and writ- MOP2.5.AnnexBfin). Advice and informa- Tina Aughney (Ireland) Peter Lina (Netherlands)
ten by the EUROBATS Intersessional Work- tion were provided by other experts. Hope- Hans Baagøe (Denmark) Simon Mickleburgh (BCT, United Kingdom)
ing Group (IWG) on Producing Guidelines fully all contributors are listed here, but if Petr Benda (Czech Republic) Katie Parsons (BCT, United Kingdom)
on Bat Monitoring Methods to Assess we have missed anyone please accept our Ian Davidson-Watts (United Kingdom) Igor Pavlinic´ (Croatia)
Population Trends at Different Levels. The apologies and many thanks for your contri- Jasja Dekker (Netherlands) Boyan Petrov (Bulgaria)
IWG was set up to deliver recommenda- bution. Péter Estók (Hungary) Paul Racey (United Kingdom)
tions of Resolution 2.2 (Doc.EUROBATS. Jacques Fairon (Belgium) Roger Ransome (United Kingdom)
Frank Greenaway (United Kingdom) John Russ (United Kingdom)
Gareth Jones (United Kingdom) Peter Smith (United Kingdom)
Members of the IWG:
Branko Karapandža (Serbia) Andriy-Taras Bashta (Ukraine)
Peter Kanuch (Slovak Republic) Ludy Verheggen (Netherlands)
Jessamy Battersby (United Kingdom, IWG Lauri Lutsar (Estonia)
Gerald Kerth (Switzerland)
convenor and main editor) Ferdia Marnell (Ireland)
Stéphane Aulagnier (France) Matti Masing (Estonia)
Serghei Andreev (Moldova) Edvardas Mickeviciusˇ (Lithuania)
Zoltán Bihari (Hungary) Branko Micevski (FYR Macedonia)
Peter Boye (Germany) Tony Mitchell-Jones (United Kingdom)
Colin Catto (BCT, United Kingdom) Dumitru Murariu (Romania)
Martin Celuch (Slovak Republic) Ioseb Natradze (Georgia)
Eva Cepakova (Czech Republic) Marie Nedinge (Sweden)
Amy Coyte (BCT, United Kingdom) Gunars Petersons (Latvia)
Viktar Dziamianchyk (Belarus) Jaques Pir (Luxembourg)
Edmée Engel (Luxembourg) Primož Presetnik (CKFF, Slovenia)
Suren Gazaryan (Russian Federation) Luísa Rodrigues (Portugal)
Melanie Hardie (United Kingdom) Bernd-Ulrich Rudolph (Germany)
Daniela Hamidovic´ (Croatia) Danilo Russo (Italy)
Christine Harbusch (NABU, Germany) Dino Scaravelli (San Marino)
Karen Haysom (BCT, United Kingdom) Yrjo Siivonen (Finland)
Tony Hutson (IUCN, United Kingdom) Friederike Spitzenberger (Austria)
Teodora Ivanova (Bulgaria) Abigel Szodoray-Paradi (Romania)
Katherine Jones (BCT, United Kingdom) Triinu Tõrv (Estonia)
Branko Karapandza (Serbia ) Nikola Tvrtkovic´ (Croatia)
Andrzej Kepel (Salamandra, Poland) Lubomira Vavrova (Slovak Republic)
Eeva-Maria Kyheröinen (Finland) Bronislaw Woloszyn (Poland)
Herman Limpens (Netherlands)

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