Ron J.

Johnson
Extension Wildlife Specialist
Department of Forestry, Fisheries
AMERICAN CROWS
and Wildlife
University of Nebraska
Lincoln, Nebraska 68583-0819

Fig. 1. American crow, Corvus brachyrhynchos

(also called the common crow or eastern crow)

Damage Prevention and Frightening Trapping

Control Methods Use with roosts, crops, and some other Check laws before trapping.
situations. Frightening devices Australian crow decoy traps may
Exclusion include recorded distress or alarm be useful near a high-value crop or
calls, pyrotechnics, various sound- other areas where a resident
Netting to exclude crows from high-
producing devices, chemical population is causing damage.
value crops or small areas.
frightening agents (Avitrol®), lights, Proper care of traps and decoy
Protect ripening corn in gardens by bright objects, high-pressure water birds is necessary.
covering each ear with a paper cup spray, and, where appropriate,
Capture single crows uninjured in size
or sack after the silk has turned shotguns.
No. 0 or No. 1 steel traps that have
brown. Repellents the jaws wrapped with cloth or rub-
Widely-spaced lines or wires placed ber.
None are registered.
around sites needing protection Shooting and Hunting
may have some efficacy in repelling Toxicants
crows, but further study is needed. Helpful as a dispersal or frightening
None are registered
technique but generally not effective
Cultural Methods
in reducing overall crow numbers.
Alternate or decoy foods; example: Crows may be hunted during open
scatter whole corn, preferably seasons. Check with your state
softened by water, through a field wildlife agency for local restrictions.
to protect newly planted corn
seedlings.

PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994

Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
E-33
Great Plains Agricultural Council
Wildlife Committee
 Identification quent steady wing-beat with little or ing grasshoppers, beetles, beetle larvae
no gliding. (white grubs, wireworms), caterpillars,
The American crow (Fig. 1) is one of spiders, millipedes, dead fish, frogs,
Chihuahuan ravens occur in the South-
America’s best-known birds. Males salamanders, snakes, eggs and young
west, including portions of western
and females are outwardly alike. Their of birds, and carrion such as traffic-
Kansas, Colorado, Oklahoma, Texas,
large size (17 to 21 inches [43 to 53 cm] killed animals. The remainder of the
New Mexico, and Arizona and rarely
long), completely coal-black plumage, crow’s diet consists of vegetable or
in south-central Nebraska. This raven,
and familiar “caw caw” sound make plant matter. Corn is the principal food
which is smaller than the common
them easy to identify. They are fairly item in this category, much of it
raven and somewhat larger than the
common in areas near people, and obtained from fields after harvest.
American crow, can be distinguished
tales of their wit and intelligence have Crows also consume acorns, various
from the crow by its call, slightly
been noted in many stories. wild and cultivated fruits, water-
wedge-shaped tail, and flight pattern
melon, wheat, sorghum, peanuts,
Three other crows occur in the conti- that includes gliding. The white neck
pecans, garbage, and miscellaneous
nental United States, the fish crow feathers, which account for its other
other items.
(Corvus ossifragus), the northwestern name, are seldom visible in the field.
crow (Corvus caurinus), and the Mexi-
can crow (Corvus imparatus). Fish General Biology,
crows are primarily inhabitants of the
Range
Reproduction, and
eastern and southeastern coastal
United States, but their range extends American crows are widely distrib- Behavior
into the eastern edges of Oklahoma uted over much of North America.
They breed from Newfoundland and Crows are among the most intelligent
and Texas. Fish crows are somewhat of birds. Experiments indicate that
smaller than American crows, but in Manitoba southward to Florida and
Texas, and throughout the West, American crows can count to three or
the field they appear much alike. They four, are good at solving puzzles, have
can be distinguished, however, by except in the drier southwestern por-
tions. During fall, crows in the north- good memories, employ a diverse and
their calls — the fish crow call is a behaviorally complex range of vocal-
short, nasal “ca,” “car,” or “ca-ha.” ern parts of their range migrate
southward and generally winter south izations, and quickly learn to associate
Northwestern crows, as their name various noises and symbols with food.
implies, occur in the northwest along of the Canada-US border.
One report describes an American
the coastal strip from Washington to crow that dropped palm nuts
Alaska. They are most often seen for- Habitat (Washingtonia sp.) onto a residential
aging along beaches. Northwestern street, then waited for passing automo-
crows are smaller than American American crows do best in a mixture biles to crack them. Crows are keen
crows, but in Washington state these of open fields where food can be found and wary birds. Consider the number
two species may hybridize. Mexican and woodlots where there are trees for of crows that scavenge along high-
crows occur in south Texas (Browns- nesting and roosting. They commonly ways; how many have you seen hit by
ville area) primarily during fall and use woodlots, wooded areas along autos? Crows can mimic sounds made
winter and are fairly small for crows. streams and rivers, farmlands, by other birds and animals and have
Their voice is a low froglike “gurr” or orchards, parks, and suburban areas. been taught to mimic the human voice.
“croak” or, in some areas, a higher- Winter roosting concentrations of The myth that splitting the tongue
pitched “creow.” crows occur in areas that have favor- allows a crow to talk better, however,
Ravens are similar to crows in appear- able roost sites and abundant food. is not true and is needlessly cruel.
ance. Two species occur in the conti- Crows often post a sentinel while feed-
nental United States, the common or
Food Habits ing. Although studies indicate that the
northern raven (Corvus corax) and sentinel may be part of a family group,
Chihuahuan or white-necked raven unrelated crows and other birds in the
Crows are omnivorous, eating almost
(Corvus cryptoleucus). The common area likely benefit from the sentinel’s
anything, and they readily adapt food
raven is found from the foothills of the presence.
habits to changing seasons and avail-
Rockies westward, northward to
able food supply. They belong to a Crows begin nesting in early spring
Alaska and eastward across Canada
select group of birds that appear (February to May, with southern nests
and some northern U.S. states, and lo-
equally adept at live hunting, pirating, starting earlier than northern ones)
cally in the Appalachian mountains.
and scavenging. Studies show that and build a nest of twigs, sticks, and
Common ravens can be distinguished
crows consume over 600 different food coarse stems. Crow pairs appear to
from crows by their larger size, call,
items. remain together throughout the year,
wedge-shaped tail, and flight pattern
that commonly includes soaring or About one-third of the crow’s annual at least in nonmigratory populations,
gliding. In contrast, crows have a fre- diet consists of animal matter, includ- and pairs or pair bonds are likely

E-34
maintained even within large winter over large areas to feed during the was rural and relatively wary of
migratory flocks. The nest, which is day. Crows may commonly fly 6 to 12 people. Will crows that are hatched in
lined with shredded bark, feathers, miles (10 to 20 km) outward from a urban areas be habituated to people to
grass, cloth, and string, is usually built roost each day to feed. such an extent that they will be more
18 to 60 feet (5 to 18 m) above ground difficult than their rural counterparts
Recent radio-telemetry studies indicate
in oaks, pines, cottonwoods, or other to disperse from problem sites?
that roosting crows may have two dis-
trees. Where there are few trees, crows Understanding such factors may lead
tinct daily movement patterns. Some
may nest on the ground or on the to better options for managing crows
fly each day to a stable territory, called
crossbars of telephone poles. The aver- in ways compatible with the needs of
a diurnal activity center, which is
age clutch is 4 to 6 eggs that hatch in people.
maintained by four or five birds
about 18 days. Young fledge in about
throughout the winter and apparently
30 days. Usually there is 1 brood per
then used as a nesting site in spring. Damage and Damage
year, but in some southern areas there
Although these stable groups of crows Identification
may be 2 broods. Both sexes help build
may stop at superabundant food
the nest and feed the young, and occa- Complaints associated with crow
sources such as landfills, individuals
sionally offspring that are 1 or more damage to agriculture were more com-
within the groups typically fly differ-
years old (nest associates) help with mon in the 1940s than they are today.
ent routes and make different stops.
nesting activities. The female incubates Although surveys indicate that overall
Other crows appear to be unattached
the eggs and is fed during incubation crow numbers have not changed
and without specific daily activity cen-
by the male and nest associates. The appreciably, the populations appear to
ters or stable groups. Although they
young leave the nest at about 5 weeks be more scattered during much of the
use the same roosts as the activity-cen-
of age and forage with their parents year. This change has resulted appar-
ter crows, these unattached birds, pos-
throughout the summer. Later in the ently from the crows’ response to
sibly migrants, are not faithful to any
year, the family may join other groups changing land-use patterns. Farming
specific location or territory and more
that in turn may join still larger has become more prevalent in some
regularly feed at sites such as landfills.
groups. The larger groups often areas, generally with larger fields.
migrate in late fall or winter. Ongoing changes in land-use patterns Woodland areas are generally smaller,
may result in associated impacts on and trees and other resources in urban
Few crows in the wild live more than 4
crow populations and behavior. His- sites provide crow habitat. Overall, the
to 6 years, but some have lived to 14
torically, crow populations have ben- amount and degree of damage is
years in the wild and over 20 years in
efited from agricultural development highly variable from place to place and
captivity. Recently, a bird bander
because of grains available as a food year to year. Several variables enter
reported a crow that had lived an
supply and because trees became into the complex picture of crow dam-
incredible 29 years in the wild. Adult
established in prairie areas where agri- age, including season, local weather,
crows have few predators, although
culture and settlement suppressed time of harvest, amount of crop pro-
larger hawks and owls and occasion-
natural fires. The combination of food duction, and availability and distribu-
ally canids take some. Brood losses
and tree availability favored crows, tion of wild mast, insects, and other
result from a variety of factors includ-
and in some areas with abundant food foods.
ing predation by raccoons (Procyon
and available roost sites, large winter
lotor), great-horned owls (Bubo Although crows cause a variety of
roosting concentrations became estab-
virginianus), and other predators; damage problems, many of these are
lished. As the current trend toward
starvation; and adverse weather. more commonly associated with other
sustainable agricultural systems con-
One important and spectacular aspect tinues, which may include a variety of animal species. Crows may damage
of crow behavior is their congregation crops and rotations with nongrain seedling corn plants by pulling the
into huge flocks in fall and winter. crops, food availability and associated sprouts and consuming the kernels.
Large flocks are the result of many patterns of crow roosts may change. Similar damage may also be caused by
small flocks gradually assembling as other birds (pheasants, starlings, black-
The growing number of crows that birds) and rodents (mice, ground
the season progresses, with the largest
nest and roost in urban areas also squirrels). Crows at times damage rip-
concentration occurring in late winter.
raises questions. Are urban habitats ening corn during the milk and dough
The Fort Cobb area in Oklahoma, a
now selected because of adaptive stages of development. Such damage,
communal roost site, holds several
changes in crow behavior, or are however, is more commonly caused
million crows each winter. In
changes in rural settings making urban by blackbirds; for further information,
Nebraska, Wisconsin, and possibly
sites comparably more suitable? One see Blackbirds. Crows consume pea-
other states, crows appear to be roost-
study described two neighboring but nuts when they are windrowed in
ing more commonly in towns near
distinct crow nesting populations — fields to dry, but other birds, especially
people, resulting in mixed opinions on
one that was urban and somewhat ha- grackles, cause the greatest portion of
how to deal with them. These flocks
bituated to people and another that this damage. Crows may also damage
roost together at night and disperse

E-35
 other crops, including ripening grain factors that increase the potential for Lines. Another excluding or repelling
sorghum, commercial sunflowers, crows to spread this devastating dis- technique used historically to protect
pecans, various fruits, and water- ease. Also, crow and other bird (black- fields from crows is stretching cord or
melons. In rare situations, crows may bird, starling) roosts that have been in fine wire at intervals across the field at
attack very young calves, pigs, goats, place for several years may harbor the heights about 6 to 8 feet (1.8 to 2.4 m)
and lambs, particularly during or fungus (Histoplasma capsulatum) that above the ground. Sometimes alumi-
shortly after birth. This problem, causes histoplasmosis, a disease that num or cloth strips or aluminum pie
which is more often associated with can infect people who breathe in pans were tied to the wires. More
magpies or ravens, is most likely to spores when a roost is disturbed. recently, the concept of stretching
happen where livestock births occur in widely spaced lines or wires over or
unprotected open fields near large Legal Status around sites needing protection from
concentrations of crows. certain birds has received increased
Crows are protected by the Migratory attention. Crows were included in two
Another complaint about crows is that Bird Treaty Act, a federal act resulting studies at sanitary landfills, but results
they consume the eggs and sometimes from a formal treaty signed by the were somewhat conflicting. One report
the young of waterfowl, pheasants, United States, Canada, and Mexico. from South Carolina indicated that a
and other birds during the nesting sea- However, under this act, crows may 20 x 20-foot (6 x 6-m) wire grid
son. Overall, such crow depredation be controlled without a federal permit repelled crows, but another from New
probably has little effect on the num- when found “committing or about to York indicated that parallel wires
bers of these birds. However, it can be commit depredations upon ornamen- stretched 10 x 10 feet (3 x 3 m) apart
a problem of concern locally, particu- tal or shade trees, agricultural crops, and 80 x 80 feet (24 x 24 m) above the
larly where breeding waterfowl are livestock, or wildlife, or when concen- ground did not repel them.
concentrated and where there is too trated in such numbers and manner to
little habitat cover to conceal nests. For constitute a health hazard or other The reason this technique has worked
example, nests are more easily found nuisance.” for certain birds is not completely
by crows, as well as by other preda- clear, but the wires appear to represent
tors, when located in a narrow fence States may require permits to control an obstacle that is difficult for a flying
row or at the edge of a prairie pothole crows and may regulate the method of bird to see, especially when rapid
that has little surrounding cover. take. Federal guidelines permit states escape may be necessary. Various spe-
to establish hunting seasons for crows. cies respond differently to lines, and
Large fall and winter crow roosts During these seasons, crows may be generally adult birds are more repelled
cause serious problems in some areas, hunted according to the regulations by lines than juveniles. Other factors
particularly when located in towns or established in each state. Regulations such as season and/or biological activ-
other sites near people. Such roosts are or interpretation of depredation rules ity of the birds, type of lines or wires,
objectionable because of the odor of may vary among states, and state or spacing, and height need further
the bird droppings, health concerns, local laws may prohibit certain control research and development to better
noise, and damage to trees in the roost. techniques such as shooting or trap- understand the potential usefulness of
In addition, crows flying out from ping. Check with local wildlife officials lines in bird management.
roosts each day to feed may cause if there is any doubt regarding legality
agricultural or other damage prob- of control methods. Cultural Methods
lems. On the other hand, the diet of
crows may be beneficial to agriculture, Agricultural Crops. Some reports
Damage Prevention and indicate that providing an alternate or
depending on the time of year and sur-
rounding land use (see sections on Control Methods decoy food source will reduce crop
crow food habits and economics). damage caused by crows. An example
Exclusion would be scattering a grain such as
Finally, in some situations, large crow whole corn, preferably softened by
Exclusion generally is not practical for
flocks may become a factor in spread- water, through a field where crows are
most crow problems, but might be
ing disease. At times, they feed in and damaging newly planted corn seed-
useful in some situations. For example,
around farm buildings, where they lings. Although this technique has
nylon or plastic netting might be useful
have been implicated in the spread of been reported to be helpful in some
in excluding crows from high-value
transmissible gastroenteritis (TGE) situations, it has not been well tested.
crops or small areas. Protect ripening
among swine facilities. At other times,
corn in small gardens from crow or Tree Roosts. Thinning branches from
large crow flocks near wetland areas
other bird damage by placing a paper specific roost trees or thinning trees
may increase the potential for spread
cup or sack over each ear after the silk from dense groves reduces the avail-
of waterfowl diseases such as avian
has turned brown. The dried brown ability of perch sites and opens the
cholera. The scavenging habits of
silk indicates that the ear has been pol- trees to weather effects. Such vegeta-
crows and the apparent longer incuba-
linated by the corn tassels, a necessary tion management has effectively
tion time of the disease in crows are
step in corn grain development.

E-36
dispersed starling/blackbird roosts, situations. Hanging mylar tape in roost Pesticide and chemical frightening
and the same biological concepts indi- trees may be helpful in urban areas. A agent, available in a whole-corn bait
cate probable effectiveness in dispers- combination of several scare tech- formulation (Double Strength Whole
ing crow roosts. When roosts occur in niques used together works better than Corn) for use in dispersing crows. It is
a small number of landscape trees near a single technique used alone. Vary the only for sale to certified applicators or
homes or along streets, they usually location, intensity, and types of scare persons under their direct supervision
are in fairly dense trees where thinning devices to improve their effectiveness. and only for those uses covered by the
the branches will reduce the trees’ at- Supplement frightening techniques applicator’s certification.
tractiveness as roosts. Roosts in tree with shotguns, where permitted, to
Avitrol® baits contain a small number
groves or woodlots usually occur in improve their effectiveness in dispers-
of treated grains mixed with many
dense stands of young trees. Thinning ing crows. Ultrasonic (high frequency,
others that are untreated. Birds that eat
about one-third of the trees improves above 20 kHz) sounds are not effective
the treated portion of the bait behave
the tree stand, especially if marked by in frightening crows and most other
erratically and/or give warning cries
a professional forester. Such thinning birds because, like humans, they do
that frighten other birds from the area.
successfully dispersed blackbird/star- not hear these sounds. For a more
Generally, birds that eat the treated
ling roosts from research woodlots in detailed discussion of frightening tech-
particles die. Overall, because of the
Ohio and Kentucky, and from at least niques, see Bird Dispersal Tech-
type of damage problems associated
two problem roost sites in Nebraska. niques.
with crows, Avitrol® is unlikely to be
In dense cedar thickets, bulldozing
Animated “crow-killing” owl models used often. This product is included
strips through the roost site to remove
can frighten crows from gardens and here, however, because situations may
one-third of the habitat has also been
small fields. These are made from a arise in which its use would be helpful.
successful in dispersing birds, but soil
plastic owl model with a crow model Before using this product for crow
disturbance with this method may be
attached in such a way that the crow control, it is best to contact a qualified
hazardous if soils harbor fungal spores
appears to be in the owl’s talons. person trained in bird control work
of the human respiratory disease
Movement is supplied by mounting (someone from the Cooperative Exten-
histoplasmosis. For further informa-
the model on a weather vane and by sion or USDA-APHIS-Animal Damage
tion on roost dispersal, see Bird Dis-
adding wind- or battery-powered Control, for example) for technical
persal Techniques.
wings to the crow. assistance. For additional information
Frightening
on Avitrol®, see Blackbirds and Euro-
Clapper devices (Tomko Timer-
pean Starlings.
Frightening is effective in dispersing Clapper) have been reported by the
crows from roosts, some crops, and Nebraska Game and Parks Commis- Repellents
other troublesome sites. In a recent sion as successful in dispersing crows
from waterfowl concentration areas No repellents are registered for crow
study in California, crows were suc-
where crow roosting was destroying a control. Recent studies show that con-
cessfully dispersed from urban crow
multiple-row shelterbelt and where ditioned aversion learning, a form of
roosts using tape-recorded “squalling”
there was concern that crows were repellency, can reduce egg and possi-
calls (given by a crow struggling to es-
aggravating the spread of avian chol- bly fruit and grain crop depredation
cape from a predator) and a portable
era. A clapper device intermittently by crows. Further work and registra-
tape player commonly used by hunters
“claps,” producing a sound much like tion of an appropriate agent for pro-
to attract animals. Such dispersal
a twig snapping or like two boards ducing a conditioned aversion
allows crows to be moved from prob-
clapping together. The device can be response are needed.
lem sites to sites where they are less
likely to interfere with people. placed up in trees or at other sites close
to crow perches, making it perhaps Toxicants
In addition to recorded distress or more significant to crows as a frighten- No toxicants are registered for crow
alarm calls, frightening devices include ing device. Clappers have also been control. Special Local Needs 24(c)
gas-operated exploders, battery- used to frighten and disperse other registrations have been sought for
operated alarms, pyrotechnics, (shell- birds (starlings, grackles, swallows) DRC-1339 (3-chloro p-toluidine hydro-
crackers, bird bombs), chemical and to repel deer at night. Like many chloride) by USDA-APHIS-ADC for
frightening agents (see Avitrol® other frightening techniques, clappers limited, small-scale use.
below), lights (for roosting sites at appear to be most effective with wary
night), bright objects, clapper devices, populations. Populations that have Trapping
and various other noisemakers. Beat- habituated to people or disturbance to
ing on tin sheets or barrels with clubs such an extent that they have lost their Trapping is often less attractive than
can help in scaring birds. Spraying wariness, may not respond. other techniques because of the wide-
birds as they land, with water from a ranging movements of crows, the time
Avitrol®. Avitrol® (active ingredient: necessary to maintain and manage
hose or from sprinklers mounted in
the roost trees, has helped in some 4-aminopyridine) is a Restricted Use traps, and the number of crows that

E-37
 can be captured compared to the total
number in the area. Trapping and
removing crows, however, can be a
successful method of control at loca-
tions where a small resident popula-
tion is causing damage or where other
techniques cannot be used. Examples
include trapping damage-causing
crows near a high-value crop or in an
area where nesting waterfowl are
highly concentrated.
Two types of traps can be used to
successfully capture crows. First,
individual crows may be captured
uninjured with No. 0 or No. 1 steel
traps that have the jaws wrapped with
cloth or rubber. These sets are most
successful if placed at vantage points
in areas habitually used by crows or if
baited with a dummy nest containing a
few eggs. Check such traps at least a
twice daily. Crows captured in this
way might be used, if necessary, as ini-
tial decoys in the Australian crow trap 16"
described below, but the small number
of captures is otherwise unlikely to
affect a damage situation.
A second and more commonly used
trap for crows is the Australian Crow 2'
Trap (Fig. 2), a type of decoy trap.
These traps are most successful if used
during the winter when food is scarce.
Australian crow traps should be at b
least 8 to 10 feet (2.4 to 3 m) square
and 5 to 6 feet (1.5 to 1.8 m) high. If 10'
desired, construct the sides and top in
panels to facilitate transportation and
storage. Place the trap where crows
are likely to congregate. The most
attractive bait is meat (such as slaugh- c 6"
terhouse offal, small animal carcasses)
or eggs. Whole kernel corn, milo
10'
heads, watermelon, and poultry feed
may also work and may be preferred
where carnivores such as feral dogs
might be attracted to the trap. Place Fig. 2. Australian crow trap: (a) completed trap, (b) end view, and (c) plan of “ladder” opening.
the bait under the ladder portion of the
trap. Also provide water. After the
first baiting, the trap should not be vis-
ited for 24 hours. Once the birds begin
to enter the trap, it should be cared for
daily. Replace the bait as soon as it
loses its fresh appearance. Remove all
crows captured except for about five
to be left in the trap as decoys. Remove
captured crows after sunset when they
are calm (to facilitate handling).

E-38
Should any nontarget birds be cap- Crow hunting during open season can near people appear to be increasing.
tured, release them unharmed imme- be encouraged in areas where crows Individuals experiencing damage
diately. Euthanize captured crows cause problems. The helpfulness of problems should weigh the costs of
humanely by carbon dioxide exposure hunting as a control technique varies control against the amount of damage,
or cervical dislocation. A well-main- depending on crow movements, the then work with the proper authorities
tained decoy trap can capture a num- season in which the damage occurs, to develop a control program.
ber of crows each day, depending on and other factors. Another consider-
On the beneficial side, the crow diet in-
its size and location, the time of year, ation is that crows tend to be more
cludes large numbers of insects consid-
and how well the trap is maintained. wary of people when they are hunted
ered harmful to agriculture, as well as
and thus more easily dispersed from
A recent study in Israel of hooded mice and carrion. In addition, their
roosting or other areas where their
crows (Corvus corone), which are about consumption of waste grain left in
presence is a problem. Further study is
the same size as American crows, indi- fields may help prevent undesirable
needed to better understand the rela-
cated that decoy crows were more volunteer corn in the following year’s
tionships between hunting and
important than bait to trap success. crop. The fact that crows also eat
wariness, and whether a pattern exists
Using one hooded crow decoy bird, snakes may be considered a benefit by
that might be used to improve crow
however, appeared to be as effective as some people.
management programs.
using three to four, and fleshy baits
Overall, crow and other bird problems
did increase success in some cases. To
prevent hooded crow escape, the lad- Economics of Damage can be difficult or frustrating to resolve
satisfactorily with the methods and
der gap width of the American model and Control
understanding currently available.
was reduced from 18 to 12 inches (45
The economics of crow damage often Persistence and use of a variety of
to 30 cm), and 1.5 x 0.8-inch (4 x 2-cm)
center around a widespread contro- techniques may be necessary to help
square rungs were used instead of
versy over whether crow feeding prevent damage. In addition, further
3-inch (8-cm) diameter metal rods. The
habits are harmful or beneficial. Some research is needed to develop damage
potential response of American crows
say that crows earn their keep by tak- control methods based on an under-
to such trap modifications is unknown
ing harmful insects and cleaning up standing of bird problems in relation
but merits study.
carrion. Others say the damage done to agricultural and urban landscapes
Shooting and Hunting far outweighs any beneficial aspects. and other natural resource systems
Despite some studies of the crow diet, where damage occurs.
Shooting is more effective as a disper-
little quantitative information is avail-
sal technique than as a way to reduce
able on the overall economic impacts Acknowledgments
crow numbers. Crows are wary and
of crows. In addition, it appears likely
thus difficult to shoot during daylight
that the economics of crows in relation The references listed under “For Additional
hours. They may be attracted to a con-
to agriculture or people have changed Information” and many others were used in
cealed shooter, however, by using preparing this chapter. Gratitude is extended to
from what they were 30 or more years
crow decoys or calls, or by placing an the authors and the many researchers and
ago when many crow studies were observers who contributed to this body of
owl effigy in a conspicuous location.
done. knowledge. I extend special appreciation to R.
Generally, the number of crows killed
W. Altman, retired Oklahoma State University
by shooting is very small in relation to At one time several state legislatures extension wildlife specialist, for his contribu-
the numbers involved in pest situa- appropriated funds for bounties on tions as co-author of the first edition of this
tions. However, shooting can be a crows and for bombing crow roosts, chapter. I also thank M. M. Beck, R. M. Case, R.
and suggested all-out efforts to eradi- Kelly, and R. Ross for comments and helpful
helpful technique to supplement and
advice on the first edition; J. Andelt provided
reinforce other dispersal techniques cate the crow. Now, most state wildlife typing and technical assistance. I gratefully
when the goal is to frighten and dis- and agriculture departments report acknowledge M. M. Beck, C. S. Brown, R. M.
perse crows rather than specifically to only a few scattered complaints of Case, and R. L. Knight for valuable reviews of
crow damage each year. At times, this second edition.
reduce numbers. For more details on
dispersal, see Bird Dispersal however, individual farms or crops do Figure 1 by Emily Oseas Routman, University of
Techniques. suffer severe damage, and concerns Nebraska-Lincoln.
about large crow roosts in urban areas Figure 2 from E. R. Kalmbach (1939).

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