Ornithol Sci 21: 1 – 8 (2022)

ORIGINAL ARTICLE

The breeding ecology of Oriental Skylark Alauda gulgula on

farmland in the Mardan District, Khyber Pakhtunkhwa,
Pakistan
Asif SADAM1,#, Rahmat Ullah KHAN2, Karim GABOL2, Muhammad AWAIS3 and Ijaz KHAN4
1
Department of Zoology, Hazara University, Mansehra, 21300, Pakistan
2
Department of Zoology University of Karachi, Karachi, Pakistan-7520
3
Department of Zoology Abdul Wali Khan University Mardan, Khyber Pakhtunkhwa, Pakistan
4
Department of Microbiology, Hazara University, Mansehra, 21300, Pakistan

Abstract Research on the breeding ecology of birds is key to understanding not only
ORNITHOLOGICAL their ecological, evolutionary and behavioral traits but also for developing effective
SCIENCE conservation strategies. We studied the breeding ecology of Oriental Skylark Alauda
© The Ornithological Society gulgula on farmland in the Mardan District, Khyber Pakhtunkhwa Pakistan from
of Japan 2022 April to July 2018. Nests were searched for systematically in all potential farmland
sites. A total of 39 nests was found, of which 25 were active. Nests were cup shaped
or somewhat oblong mainly concealed within 15 – 25-cm tall grasses. Nests were
constructed of local grasses and dry leaves of trees and local crops. The average nest
mass was 17.20±0.9 g. Average nest measurements were: outer diameter 9.17±0.8
cm, inner diameter 7.65±0.6 cm and inner cup depth 6.45±0.5 cm. Eggs were oval
in shape and dusty-grey in colour with dark grayish spots more concentrated on the
broader end. The average egg mass was 3.0 ± 0.13 g. Average egg measurements
were: width 2.30±0.4 cm, egg length 3.25±0.17 cm2 and egg volume 3.68±0.07 cm3.
The average incubation lasted 12.08±0.7 days and the nestling period was 12.59±0.5
days. The average clutch size was 3.16±0.9 eggs, and brood size averaged 2.76±0.7
nestlings. Fledgings were found from early May to late July. The average number of
young fledged was 2.18±0.7 and overall breeding success was 60.75%. Results sug-
gest that farmland represents a good yet risky breeding habitat for the skylarks. Fac-
tors such as nest destruction, grazing, predation, agricultural disturbance and human
intervention are affecting the breeding success of Oriental Skylark in Pakistan.

Key words Alauda gulgula, Breeding, breeding success, farmland, oriental skylark

Detailed data on a species’ breeding ecology is may be met by modification of reproductive strate-
key to understanding its ecological and behavioral gies (Martin 1993). Clearly, more research into the
traits, and for generating general theories of life-his- breeding ecology of ground nesting birds is needed
tory evolution patterns and processes (Covas 2012). for a better understanding of their evolution and life
The breeding process is the most important aspect history traits.
of the life-history traits of birds and is the key pro- Farmland bird species globally are suffering
cess that determines the dynamics of bird popula- severe population declines. Agricultural intensifica-
tions (Martin 2002). Food limitation is an important tion, including increasing field sizes, promoting large
issue in ecology because it can influence life history scale monocultures, reducing mixed farming and
traits, population sizes and community structures. developing practices that maximize yields, is degrad-
Food limitation can be expressed in different ways; ing semi-natural habitats throughout Europe. Such
food limitation in winter may lead to morphologi- factors decrease food availability and safe breeding
cal adaptations, whereas food limitation in summer sites for birds (Praus & Weidinger 2015). In Europe,
Eurasian Skylark Alauda arvensis population den-
(Received 7 January 2021; Accepted 3 September 2021) sity has dropped over the last 30 years due to rapid
#
Corresponding author, E-mail: saddamasif2@gmail.com amplification of farming land (Praus &Weidinger

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 A. SADAM et al.

2010). Skylark species are therefore considered prior- number of settlements mainly of farmers. The agri-
ity species associated with agriculture and cultivated cultural landscape includes three components: agri-
lands are therefore considered to be priority taxa cultural crops, grasslands, and trees. Tree species here
for conservation and rehabilitation (Gregory et al. include both local indigenous trees and ornamental
2005). Predation and agricultural disturbance nega- trees that provide nesting habitats for many bird spe-
tively affect the nesting of farmland and song birds cies. Additionally, a ground flora of herbs, shrubs,
(Wilson & Browne et al. 1993). The main reason for and ground weeds is present that also provide food
egg disappearance and nestling death is the presence sources for many birds. An 8.09 ha forest area, with
of potential predators such as feral dogs Canis famil- planted Eucalyptus Eucalyptus globulus, Chinaberry
iaris, Golden Jackal C. aureus, House Crow Corvus Tree Melia azedarach and Populus Populus alba, is
splendens and Little Owl Athene noctua (Shurulinkov also the part of agricultural area. Ballar Stream is
2005; Li & Lu 2012a,b; Du et al. 2014). Mammalian the main water body of the area, it originates in the
and avian predators are also involved in egg disap- Sudhum Valley, flows from northeast to southwest
pearance and nestling death (Donald & Morris 2005; and finally joins Kalpani Stream at Mardan. Kalpani
Du et al. 2014). Crows Corvus spp. are the main Stream drains into the Kabul River (Sadam et al.
reason for nestling mortality also in the lower Volga 2021). The region has a hot semi-arid climate. Sum-
region of Russia (Shurulinkov 2005). mer, which commences in May and June, is very
The Oriental Skylark Alauda gulgulais a small hot, with a rapid rise in temperature reported during
Passeriformes bird that ranges across Asia including these months. Maximum temperatures reach 43.5 C°
northern Pakistan, as well as parts of Europe and in June. Winter lasts from November to January, with
Africa (Gabol & Khan 2021). Of the four skylark average minimum temperatures of 0.5 C° reached
species in the genus Alauda (family Alaudidae), the during December and January. Most rainfall is during
Oriental Skylark is a particularly small species (ca. July, August, December and January.
30 g; Gabol & Khan 2021).Oriental Skylark, is the
only passerine bird that shows a great association 2) Field survey
with agricultural farmland (Praus & Weidinger 2010). Data on the breeding parameters of Oriental Sky-
Territory sizes differ, but average 5,000 – 20,000 m2 in lark were collected on the farmland of Mardan Dis-
Tibet (Li et al. 2015). Pairs change their territories in trict (total area 60 km2). Searching for nests was
response to changes in vegetation and environmental undertaken from the beginning of the breeding season
conditions (Li et al. 2015). in mid April and continued until late July, in 2018.
Although the Oriental Skylark is widespread, with Nests were searched for systematically on a daily
the exception of some simple descriptions its natural basis, with a total of 100 days devoted to nest search-
history is poorly understood (Gabol & Khan 2021). ing throughout the study area. Nests were found by
This paper is the first to describe the breeding ecol- investigating potential nest sites in the area, by flush-
ogy of Oriental Skylark from the farmland of Khyber ing birds from their nests or by incidental encoun-
Pakhtunkhwa, Pakistan. ters in the study area. Once found, the nests were
numbered serially for data collection. Local farmers
and children also helped us in locating potential nest
MATERIALS AND METHODS
sites. Active nests were checked three times a week
1) Study area to record egg laying date, clutch size, brood size,
Data were collected from the farmland of the Gujrat hatching and nest failures (Marini et al. 2012). When
union council located in the Mardan District, Khyber the exact dates of incubation were unknown, egg
Pakhtunkhwa, Pakistan. The area located at a distance laying dates were estimated from other known dates
of 10 km from central Mardan (34°18′46.6488″N, or from the laying interval (Martin 2002). Data on
72°9′1.1304″E) has an irrigation system. To the the breeding season, egg shape, colour, and texture
north lies the Buner District and the protected area were also recorded. A digital camera was used to
of Malakand, to the east are the Sawabi and Buner photograph the nests, eggs and nestlings. Data were
districts, to the south is the Nowshera District, and recorded causing minimum disturbance to the habi-
to the west the Charsadda District and protected area tat, birds, and their nests following Martin (1993).
of Malakand (Sadam et al. 2021). The area has a Vernier calipers were used to measure eggs.A digi-
relatively low human population including a small tal scale (0.1 – 1,000 g) was used to weigh eggs and

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 Breeding ecology of Oriental skylark

nests. Egg volume was calculated using the following Table 1. Nest characteristics of Oriental Skylark in Pakistan
formula: (N= 39).

Volume = KvXLW 2 Particulars Mean±SD Range

Where “KV” is a constant= 0.51, and “L” and “W2” Nest weight 17.20±0.9 16.4–18.8 g
are the length and width of skylark eggs respectively. Outer diameter 9.17±0.8 8.2–11 cm
Eggs destroyed during nest destruction or preda- Inner diameter 7.65±0.6 5.8–7 cm
tion was excluded from clutch size calculation. Nest Cup depth 6.45±0.5 5.7–7 cm
destruction was defined as when nests were found
completely damaged. This was usually in association
with signs of tractor tyres or livestock footprints near
or on the damaged nests. Egg predation was defined
as when eggs disappeared and were no longer pres-
ent in a nest. Hatching success, fledging success, and
overall breeding success were calculated by employ-
ing the following formulas (Kour & Sahi 2013):

Volume = KvXLW 2

Number of egg hatched

Hatching success % = ×100
Total egg laid

Number of fledging
Fledging success % = ×100
Number of egg hatched

Number of fledging
Breeding success % = ×100
Total number of egg laid Fig. 1. Nesting materials used by Oriental Skylark.

3) Statistical analysis cm (range 5.7 – 7 cm). After fledging, nests were

Oriental Skylarks nests were located on the farm- weighed using a digital balance. Nest mass averaged
land. Insufficient nests were found in neighboring 17.20 ± 0.9 g (range 16.4 – 18.8 g) (Table 1). Most
grassland or other habitats for comparison of breeding nests (85.6%) were completely round; the remaining
parameters in different habitats. Results are presented 14.4% were partially oblong. Nests were constructed
as means with standard deviations (Mean ± SD) and using local grasses and dry leaves of trees and local
as percentages (%). crops including: Halfa Grass Desmostachya bipinnata
(19%), Couch Grass Cynodon dactylon (18%), Spear
Grass Heteropogon contortus (15%), Curved-awn
RESULTS
Fimbristylis Fimbristylis squarrosa (12%), Common
1) Nest Reed Phragmites communis (7%), local crops (3%),
A total of 39 nests were found of which 25 were Marvel Grass Dichanthium annulatum (2%), plastic
active. All nests were constructed on the ground string (2%), contour feathers (2%) and undifferenti-
amongst open vegetation and all were well concealed ated materials (2%) (Fig. 1).
by local grasses (15 – 25 cm tall) in natural vegeta-
tion and in wheat and barley fields. As all nests were 2) Egg laying, clutch size and brood size
complete when found we were unable to record the Eggs were smooth, oval and grayish-white or dusty
levels of participation of males and females in nest with deep brown spots (Fig. 4.C). Eggs were laid on
construction. The external diameter of nests aver- consecutive days (N = 5) until clutch completion or
aged 9.17±0.8 cm (range 8.2 – 11 cm). The inner nest with one day interval (N = 20). The laying date of
cup diameter averaged 7.65 ± 0.6 cm (range 5.8 – 7 the first egg was recorded at five nests allowing us
cm) (Table 1). Internal cup depth averaged 6.45 ± 0.5 to calculate the active egg laying period as lasting

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 A. SADAM et al.

ranged from 15 April to 2 June (Fig. 2). 3) Incubation and Nestling period
Eggs morphometric were recorded for 79 eggs from Of 39 nests found, incubation commenced in 25 of
25 active nests. Egg width averaged 2.30 ± 0.4 cm them.Incubation, by the female alone, began within
(range 2.1–2.3 cm). Egg length averaged 3.25 ± 0.17 one day of clutch completion. The incubation period
cm2 (range 3.24 – 3.50 cm). Egg volume averaged of averaged 12.08 ± 0.7 days (range 11 – 13 days). The
3.68±0.07 cm3 (range 3.6 – 3.8 cm3). Egg mass aver- nestlings period averaged 12.59 ± 0.5 days (range
aged 3.0±0.13 g (range 2.9 – 3.1 g) (Table 2). Clutch 11 – 13 days) (Table 4).
size averaged 3.16 ± 0.9 eggs (range 2 – 4), and brood
size averaged 2.76 ± 0.7 nestlings (range 2 – 4) (Table 4) Egg and nestling loss
3). Of the 79 eggs laid in 25 nests 3.8% (n = 3) failed
during incubation and 8.8% (n = 7) were predated. Of
the 69 nestlings that hatched, 17.39% (n = 12) were
killed by farm vehicles, mainly tractor, and 13.04%
(n = 9) died before fledging (Table 5). The first and
second authors observed a group of seven children
around one Oriental Skylark nest disturbing the
chicks, and such behavior may be the leading cause
of nestling mortality.

5) Hatching success
Of the 39 nests located, hatching occurred at 25
(64.10%). Nine nests were destroyed by grazing
cattle, two were demolished by human intervention,
mainly by children, and three were destroyed by agri-
cultural machinery (Table 6). A fully grown 14-day
old nestling weighed 27.5 g.
Fig. 2. The distribution of first laying dates by Oriental Sky-
lark during the 2018 breeding season.
Table 4. Incubation period (N = 25) and nestling period in
successful clutch (N= 22) of oriental skylark

Table 2. Egg mass and egg dimensions (N = 25) of Oriental Number of Nest
Skylark.
Days Incubation period Nestling period
Particulars Mean ± SD Range
11 6 1
Egg mass 3.0 ± 0.13 2.9 – 3.1 g 12 11 7
Egg width 2.30 ± 0.4 2.1 – 2.3 cm 13 8 14
Egg length 3.25 ± 0.17 3.24 – 3.50 cm2
Mean±SD 12.08±0.7 12.59±0.5
Egg volume 3.68 ± 0.07 3.6 – 3.8 cm3

Table 5. Overall egg and nestling loss in oriental skylark

Table 3. Clutch Size and brood size (N = 25) of Oriental
(N= 25).
Skylark.
Particulars Number Percentage
Number of Nests
Number of eggs 79 100
Clutch/Brood Clutch size Brood size
Egg loss Failed eggs 3 3.8
2 9 11 Egg predated 7 8.8
3 3 9
Number of nestling 69 100
4 13 5
Nestling loss Died by tractor 12 17.39
Mean ± SD 3.16 ± 0.9 2.76 ±0.7 Nestling died 9 13.04

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 Breeding ecology of Oriental skylark

6) Fledging Table 8. Number of young fledged (N= 22).

During nestling period both the parents fed the
No. of young fledged Number of nest
chicks. Of the 25 active nests, fledging occurred
from 22 (88%). Two nests were destroyed by human 1 4
intervention and anthropogenic ignorance, and one 2 11
nest disappeared from the site (Table 7). First fledg- 3 6
ing was recorded in early May (N = 4) and continued 4 1
until late July (N = 22) (Fig. 3). The number of young Mean±SD 2.18±0.7
fledged averaged 2.18 ± 0.7 (range 1 – 4) (Table 8).

Table 6. Hatching success during egg laying and incubation Table 9. Overall breeding success and productivity (N= 22).
in Oriental Skylark.
Particulars Success/Productivity
Particulars Number of nest
No of eggs laid 79
Total nests 39 No of nestlings 69
Hatching success 25 Hatching rate % 87.34
Success rate % 64.10 No of young fledged 48
Destroy by cattle 9 (23.07) Fledging rate % 69.56
Nest demolished 2 (5.12) Overall breeding success 60.75
Destroy by tractor 3 (7.69)

7) Breeding success
Table 7. Fledging success and nest failure during the brood A total of 79 eggs was laid in 25 active nests,
rearing period in Oriental Skylark 69 (87.37%) of which hatched. Of the 69 eggs that
hatched 48 (69.56%) young fledged. Overall breeding
Particulars Number of nest
success (number fledging/number of eggs laid× 100)
Nest examined 25 was 60.75% (Table 9).
Fledging Success 22
Success rate % 88
DISCUSSION
Nest disappear 1 (4)
Human intervention 2 (8) In Mardan District, in 2018, the Oriental Skylark’s
breeding season began in mid-April and continued
until late July. The entire breeding cycle lasted for
95 days. During this period we studied single broods.
While Oriental Skylarks may raise a second brood,
we were unable to determine whether the same par-
ents returned to the same area for nesting because
they were not individually marked. In future, we aim
to use color banding and molecular techniques to
allow the identification of individuals and determine
the sex ratio of parent birds.
All nests were found on the ground in arid areas.
On the Tibetan Plateau the Oriental Skylark simi-
larly selects dry habitat for nest construction, choos-
ing sites with dense grasses that help conceal them
from avian and terrestrial predators (Li et al. 2015).
Li et al. (2015) reported that Oriental Skylarks in
Tibetbegin nest building in early April and lay eggs
from early May to mid-July. Our observations in
Fig. 3. Fledging dates and fledging period of Oriental Skylark. Mardan District were very similar, with nesting begin-

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 A. SADAM et al.

Fig. 4. A. Parental Oriental Skylarak B. Nest with eggs C. Laying order of eggs D. Hatched nestlings
(Photographs taken by Rahmat Ullah Khan in 2018).

ning from mid-April and the earliest eggs were laid studied the breeding ecology of the ground nest-
on May 12. The small difference in breeding phenol- ing Wood Warbler Phylloscopus sibilatrix, in for-
ogy between Tibet and Pakistan may be attributed to est and suggested that the similar seasonal variations
differences in local climatic conditions. In addition, in clutch sizes was an adaptation to the changes in
in this study, the nestling period was longer than food availability and predation pressure. However
the two previously mentioned populations. One of in this study we have found no obvious evidence
those populations belonged to a different species, and for the support of the predation pressure hypothesis.
direct comparisons are not given. Possible reasons Breeding period is a phylogenetic trait that does not
for differences in the length of the nestling period vary between eastern and western edges of a species
may include: 1) as the study site was a rural farmland range. However the clutch and brood sizes varied
mosaic, frequent human interference may have dis- between habitats (Wesolowski 1985).
rupted the normal parental behavior of the birds, thus In our study of the Oriental Skylark, the average
affecting the growth and survival of nestlings; and 2) incubation period was 12.08 ± 0.7 days (range 11 –13),
regular spraying of pesticides in the fields may have and the average nestling period was 12.59 ± 0.5 days
led to a shortage of food for nestlings. (range 11 – 14). Similar research on the Tibetan
Browne et al. (2000) reported that the clutch size Plateau found the incubation period to be 12.04 days
of the Eurasian Skylark increased from three to five (Li et al. 2015).
eggs during the middle of the breeding season in Kragten et al. (2008) found that the nesting suc-
Britain. In contrast, in our study the clutch size and cess of the Eurasian Skylark was just 33% in natural
brood size was two to four eggs. Wesolowski (1985) and arable fields in northern Netherlands, while Li et

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 Breeding ecology of Oriental skylark

al. (2015) found the nesting success of the Oriental Delius JD (1965) A population study of skylarks (Alauda
Skylark to be 41.3% on the Tibetan Plateau. In con- arvensis). Ibis 107: 466–492.
trast, we found a higher nesting success (57.89%) in Donald PF & Morris TJ (2005) Saving the skylark. British
Pakistan than in the previously mentioned studies of Birds 98: 570–578.
two skylark species. Female Oriental Skylarks com- DuB, Liu CJ, Yang M, Bao SJ, Guan MM & Liu NF
menceincubation of their eggs typically beginning (2014) Horned larks on the Tibetan Plateau adjust the
with the laying of the last egg, and complete incuba- breeding strategy according to the seasonal changes
tion alone, as in previous studies (Donald 2004). No in the risk of nest predation and food availability. J
evidence of brood parasitism by any cuckoo species Avian Biol 45: 466–474.
was recorded in the present study. It appeared that a Gill F Donsker D & Rasmussen P (eds) (2021) IOC
World Bird List v 11.2.
smaller number of broods was compensated for by
Gregory RD, Van SA, Vorisek P, Gmelig MAW, Noble
relatively larger clutch sizes (Wesolowski 1985). Our
DG, Foppen RP et al. (2005) Developing indicators
study of the breeding ecology of Oriental Skylark on
for European birds. Philos Trans R Soc Lond B, 360
farmland in the Mardan District of Pakistan provided (1454): 269–288.
useful information on nesting biology. Gabol K & Khan RU (2021) Breeding biology and
We suggest that the breeding success of Oriental nidology of Oriental skylark (Alauda gulgula) in
Skylark in the Mardan District of Pakistan can be district Bajaur, Khyber Pakhtunkhwa, Pakistan Pure
improved by protecting its habitat and by raising the Appl Biol 10: 1326–1337.
awareness of local people. Detailed comparative data Jose J, Moller AP & Soler M (1998) Nest building, sex-
on the ecology of Oriental Skylark as well as on ual selection and parental investment. J Evol Ecol 12:
other ground nesting birds are invited to validate and 427–441.
extend our conclusion to farmland birds in general. Kour DN & Sahi DN (2013) Aspects of breeding biology
of Cattle Egret, Bubulcus ibiscoromandus (Boddaert)
in Jammu, India. Int J Envi Sci 3: 1547–1561.
ACKNOWLEDGMENTS
Kragten S, Trimbos KB & de Snoo GR (2008) Breeding
We thank the Department of Zoology University Skylarks (Alauda arvensis) on organic and conven-
of Karachi for support and economic assistance. We tional arable farms in the Netherlands. J Agri Ecosy
also thank the farm owners who allowed us to work & Env 126: 163–167.
on their land, and the numerous farmers who pro- Li S & Lu X (2012a) Breeding biology of Rock Spar-
vided assistance during our field work. The authors rows Petroniapetronia in the Tibetan plateau, with
declare that they have no conflicts of interest. special reference to life history variation across alti-
tudes. Acta Ornithol 47: 19–25.
Li S & Lu X (2012b) Reproductive ecology of Isabelline
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