Thomas W. Seamans 

Supervisory Wildlife Biologist

USDA-APHIS-Wildlife Services 

National Wildlife Research Center

Sandusky, Ohio

Allen Gosser 

State Director 

USDA-APHIS-Wildlife Services 

Rensselaer, New York 

Human-Wildlife Conflicts

Conflicts between humans and birds likely 

have existed since agricultural practices 

began. Paintings from ancient Greek, 

Egyptian, and Roman civilizations depict 

birds attacking crops. In Great Britain, 

recording of efforts at reducing bird 

damage began in the 1400s, with books 

on bird control written in the 1600s. Even 

so, the problem persists. Avian damage to 

crops remains an issue today, but we also 

are concerned with damage to homes, 

businesses, and aircraft, and the 

possibility of disease transmission from 

birds to humans or livestock.

Successful dispersal techniques should 

capitalize on bird sensory capabilities. If 

birds cannot perceive the dispersal 

technique, it will not be effective in 

dispersing birds. 

Birds rely primarily on their vision and 

hearing to find food, avoid predators, and 

locate mates. Bird vision is quite different 

from human vision; birds can see colors 

that humans cannot perceive (including 

the ultraviolet range), and and they detect 

and use polarized light. Bird response to 

scare devices (Figure 1) that rely on vision 

Wildlife Damage Management 

Technical Series

U.S. Department of Agriculture

Animal & Plant Health Inspection Service

Wildlife Services

August 2016 Bird Dispersal 

Techniques

Figure 1. Photo of a frightened wild turkey (Meleagris 

gallopavo). 

Quick Links

Human-Wildlife Conflicts 1

Habitat Modification 2

Frightening Techniques 4

Bird Management 

Examples

7

Conclusion 8

Glossary & Key Words 10

Resources 11 
may depend on the visibility of the object to the bird, as 

“visual noise” could be ignored. With regard to hearing, 

birds generally are capable of hearing frequencies between 

1,000 to 3,000 Hertz, which is narrower than normal 

human capabilities. Since this range does not include the 

ultrasonic range, ultrasonic devices will not scare birds. 

Birds also use tactile (touch) and olfactory (smell) senses, 

but to a lesser degree. Devices based on these senses are 

not generally used for dispersal.

Not only must birds be able to perceive a dispersal 

technique, they also must interpret the technique as a 

threat to their safety. A technique that worked initially may 

fail later as birds habituate to it and no longer perceive the 

technique as threatening. For some species, the 

introduction of limited lethal control reinforces non-lethal 

dispersal techniques, as the birds again perceive the nonlethal technique as potentially dangerous. For other 

species, changing techniques is necessary, because they 

may not react to the death of a flock member and 

therefore still not interpret the scare technique as a threat. 

In either case, changing techniques and using multiple 

techniques in an integrated manner are essential for 

deterring birds from sensitive areas. 

No single technique or tool will deter birds in every 

instance or situation; there is no silver bullet. Successful 

bird dispersal involves a combination of tools and timing of 

use, as well as the skill and persistence of biologists and 

wildlife control operators (WCOs). The following sections 

offer overviews of various techniques that have been used 

to mitigate bird problems in various situations, as well as 

examples that highlight successful bird dispersal 

programs.

All birds need some combination of food, water, cover, and 

space to survive. Modify one or more of these features, 

and birds will often move to an area that better suits their 

needs. Management of vegetation can affect food, cover, 

and in some cases, space. Before starting to manage 

vegetation, survey the location to identify the species 

present. You must be aware of the birds in the area 

because the height and density of vegetation may attract 

or deter birds, depending on the species. Tall and dense 

vegetation may interfere with the birds’ ability to capture 

prey. In addition, other species may avoid taller vegetation 

because it hinders their ability to detect approaching 

predators. For those species, tall vegetation may reduce 

some bird conflicts. 

Some birds, however, prefer tall vegetation for nesting and 

feeding. For example, European starlings (Sturnus vulgaris) 

frequent areas with tall grass when in large flocks, but 

avoid these same areas when alone or in small flocks. On 

the other hand, brown-headed cowbirds (Molothrus ater) 

prefer short grass because, although there may be fewer 

insects available, the birds have easy access to them. 

Before modifying herbaceous vegetation, try to understand 

why a bird is using the area. For example, if birds are 

feeding on insects you may want to use an insecticide to 

remove the food source. If birds such as eastern 

meadowlarks (Sturnella magna) are nesting in taller 

vegetation, you could mow the vegetation to remove 

nesting habitat, but realize this may make the area 

attractive to those birds (e.g. American robin [Turdus 

migratorius]) that prefer feeding in shorter grass.

It also is possible to change the attraction of an area by 

working directly with the plants that attract offending birds. 

For example, not all herbaceous vegetation is equally 

desirable as a food source. Chemical makeup and mineral 

content of vegetation will influence the foraging on grasses 

by Canada geese (Branta canadensis). By planting turf 

grasses that are not desired by grazing birds (e.g., highendophyte fescue, centipedegrass, St. Augustine grass, 

and zoysiagrass), a landowner can make an area 

unattractive for birds which, in turn, can make birds easier 

to scare away using an audio or visual scare technique. 

Likewise, a landowner can plant trees or shrubs that do not 

provide food for birds. In cases where long established 

trees are the attraction, thin or prune the vegetation back 

by about a third to make the area less desirable. 

Page 2 WDM Technical Series—Bird Dispersal

Habitat Modification
Exclusion Techniques

Exclusion methods may be divided into two categories: 

area and ledge. The exclusion of birds from areas typically 

involves using nets or wires suspended to prevent bird access. The mesh size of the net depends on the species 

you are attempting to exclude. Netting with a 3⁄4-inch mesh 

will keep most pest birds from accessing protected areas. 

Failure to install nets properly, however, can increase surface areas for nesting or loafing. In addition, poorly installed nets can trap birds, leading to the death of birds 

and increased damage to the protected area while birds try 

to escape. When nets are hung over high value crops such 

as blueberries or grapes, the manner in which birds are 

attacking the crop (e.g., from the ground up or from the top 

down) will influence how the net should be deployed and 

the ultimate success or failure of the netting. 

Use overhead lines made of wire, nylon strings, or monofilament to prevent birds from using specific areas. The exact

reasons why lines work are unknown but the placement of 

lines in grid, parallel, or random patterns has worked to 

prevent bird access to food, loafing, or nesting areas. Spacing of the lines varies by the species that is to be excluded. 

In general, wider spacing of about 10 feet is effective for 

birds with wingspans of around 2 feet, whereas narrower 

spacing has worked for birds of smaller wingspan. Various 

species of gulls (Laridae), geese, sparrows (Passeridae), 

and swallows (Hirundinidae) have been excluded from 

feeding or loafing areas. However, some species, such as 

mallard ducks (Anas platyrhynchos), have not been deterred from using protected areas as they are willing to 

pass through even narrow overhead grids. 

Birds can be deterred from small water bodies such as 

retention ponds by covering the water surfaces with floating discs or balls. This technique will reduce evaporation, 

however, and may change water chemistry by preventing 

air from mixing with the water.

You can exclude birds from loafing or nesting on ledges in 

several ways using a variety of products (Figure 2). Metal 

flashing, wood, or stone placed on ledges at a 45° angle or 

more will exclude birds. Additionally, products are available 

that make a bird uncomfortable when it tries to use a ledge 

or some similar perching area by causing minimal amounts 

of pain. A variety of anti-perching spikes are available that 

work (in theory) either by preventing birds from perching on 

the spike with their feet or by pricking birds that attempt to 

land on them. 

Unfortunately, no single device will be effective against all 

species of birds. In general, larger birds require different 

devices than smaller birds due to the ability of different 

sized birds to fit within a series of spikes or grasp them in a 

manner that allows them to perch. Some larger hawks 

Page 3

Figure 2. Top to bottom. Daddy long legs, netting (different mesh 

sizes), bird coil, bird wire, and bird spikes. 

U.S. Department of Agriculture
(Accipitridae) have learned to grab hold of the spikes and 

use them as a perch. 

As with any mechanical device, to be effective, spikes must 

be maintained and used against species for which they are 

intended. For example, when a series of ledges are 

involved, if spikes on lower ledges are covered with 

material dropping down from upper ledges, they will be 

ineffective. Some birds actually learn to drop nesting 

material onto the spikes so that the spikes help to form a 

base for the nest. Maintenance of the sites will prevent this 

from happening. 

Shock strips produce a slight electrical shock to birds that 

land on them. They should remain effective as long the 

strips have electrical power and the area is kept clean 

enough to prevent the strips from shorting out. 

A wide variety of acoustical and visual tools and methods 

are available or under development to frighten birds. Not 

all devices have been through scientific testing, so the 

consumer must determine whether product claims are 

logical and whether the product is likely to work under the 

conditions of the problem facing the consumer. 

Auditory Techniques

Birds are attuned to sounds in their environment, including 

bioacoustic sounds such as alarm or distress calls. Birds 

make alarm calls when they observe a predator that 

presents a threat. Birds make distress when they are 

injured or traumatized. Either call tends to be speciesspecific, although some birds in mixed flocks react to calls 

from other species within the flock. How a bird reacts to 

calls depends in part upon the time of year in relation to 

breeding, frequency of predation risk, distance to escape 

cover, approach of the predator, type of habitat, and 

behavior of flock members. When used at the correct time 

and place, both types of calls may cause birds to disperse, 

although many species are first attracted toward the call to 

learn what danger is present. High quality recordings of 

alarm and distress calls are available. Use them at a 

volume that birds are accustomed to hearing. It is not 

helpful to play calls louder than how the birds normally 

hear or perceive the call. 

Birds habituate to repeated alarm and distress calls in the 

absence of any threat. Calls are more effective in 

dispersing birds when used with other methods (e.g., 

pyrotechnics, limited lethal control) that present a clear 

threat. Activating acoustic devices only when birds are 

present may prolong their period of effectiveness. 

Generic sounds, whether recordings of actual events (e. g., 

gunshot, car horn) or synthetically made noises, may show 

immediate results, but birds tend to habituate quickly to 

them unless the sounds cause or are accompanied by pain 

or discomfort. As with bioacoustics, integrate other control 

activities that represent a threat into programs using 

sounds. Devices that produce ultrasonic sounds are not 

effective because birds do not hear within the ultrasonic 

range. 

Pyrotechnics are a commonly used and effective bird 

dispersal tool. Pyrotechnics are specially designed 

explosives that may be fired from shotguns or adapted 

firearms (e.g., starter pistols) that shoot only pyrotechnics. 

Common pyrotechnics include shell crackers, screamers, 

bird bangers, and bird bombs. Each of these produces a 

loud sound; some also produce a flash of light and puff of 

smoke as they are fired or explode. Screamers usually 

make a wavering noise, leave a trail of smoke, and fly 

erratically. Bird bangers create a blast that mimics the 

sound of a shotgun. The most effective type of pyrotechnic 

for any given situation depends upon the location where it 

is to be fired, the types of birds to be scared, and the range 

that is required to reach the birds. Although mixing 

different types of pyrotechnics can slow habituation, 

eventually most birds become habituated, especially if the 

site being defended is highly attractive to the birds and the 

same style of pyrotechnics is used repeatedly. In such 

situations, some species of birds may again react to 

pyrotechnics if limited lethal control via a shotgun or rifle is 

used against the flock. Research has shown limited lethal 

control works well against gulls, but not as well against 

crows (Corvidae) or blackbirds (Icteridae). Local and 

Page 4

Frightening Techniques

WDM Technical Series—Bird Dispersal
national restrictions on the purchase, storage, and 

transport of pyrotechnics may preclude use by some people. Local ordinances may also limit use of pyrotechnics. 

Care must be taken because pyrotechnics can cause fires 

and leave debris behind that can cause damage to equipment or aircraft.

Propane cannons or gas exploders generate a blast that 

sounds like a shotgun from a stationary location. Cannons 

may be timed to go off at specific intervals, or be remotely 

fired by observers when birds are near the cannons. Although propane cannons are effective in some situations, 

habituation is common, especially with cannons timed to 

go off at specific intervals. The time to habituation may be 

extended by moving the cannons periodically, by firing cannons only when birds are present, and by integrating other 

scare tactics to supplement cannons.

Visual Techniques

Visual deterrents stimulate either an innate avoidance or a 

learned response that often is reinforced by another control technique. Bright lights such as spot lights, strobe 

lights, and flashing lights can be used to disperse birds for 

short periods of time. Products that use sunlight to create 

bright reflections also purportedly disperse birds. Although 

there have been reports of initial success in keeping birds 

away for a few days, numerous studies with a variety of 

species have failed to demonstrate success for humanmade lights or reflected sunlight (except for lasers, see 

below) in continually dispersing birds.

Red or green lasers have been effective at scaring some 

species of birds. Red lasers work best in the dark while 

green lasers work both in dark and low-light conditions. It is 

unclear whether birds that do not react fail to see the laser 

(birds perceive colors differently than humans) or they do 

not recognize it as a threat. The reaction of some species, 

such as Canada geese and American crows (Corvus 

brachyrhynchos), may be diminished under increased ambient lighting or where there are no alternative roost areas. 

Use lasers with caution due to their range and potential to 

affect human vision. Be careful to keep laser beams from 

striking the cockpit of an aircraft as they can cause flash 

blindness. This could result in hazardous situations for 

people on the aircraft and the ground and a visit from law 

enforcement officers.

People of many cultures have used scarecrows, dead birds, 

predator-like devices, and effigies of various other types 

over the centuries. Simulated predators, like plastic owls 

and hawks, often are used unsuccessfully to keep birds 

from roosting or nesting in specific areas. Two-dimensional 

cutouts of coyotes (Canis latrans) have shown some initial 

success but birds quickly habituate to them. Taxidermy 

mounts of coyotes, when routinely moved around airports 

that also employ other control methods, have been effective against Canada geese. Birds quickly learn that effigies 

left in the same location over a prolonged period do not 

represent a threat. The use of effigies has met with mixed 

success. Canada geese initially may react to plastic goose 

effigies but usually habituate within a short period. Effigies 

consisting of actual carcasses and artificial decoy-like vulture effigies hung by their feet in conspicuous locations 

where they move in the wind have been used to displace 

turkey (Cathartes aura) and black (Coragyps atratus) vultures from roosts for extended periods. Gull effigies have 

repelled gulls from loafing areas but have shown limited to 

no success when used in nesting colonies or at highly desired feeding sites. Human effigies (scarecrows) have been 

used for hundreds of years, but usually are of limited value 

in deterring birds unless they are enhanced by adding 

movement or integrating additional control measures, such 

as limited lethal control. 

Flagging and other materials that move in the wind have 

shown mixed effects as visual repellents. Mylar® ribbon or 

tape has effectively deterred some species of birds, including blackbirds, gulls, house sparrows (Passer domesticus), 

and Canada geese, from agricultural crops and loafing areas. However, other species, such as American robins, gray 

catbirds (Dumetella carolinensis), house finches 

(Carpodacus mexicanus), American gold finches (Carduelis 

tristis), and mourning doves (Zenaida macroura), have ignored this device. The reaction of gulls varies, as they 

avoid Mylar-style flagging when it is used in loafing areas 

but ignore it when it is used in established nesting colonies. In general, birds exhibit a neophobic response to 

flashing pie pans, aluminum foil, colored ribbon, plastic 

bags, and any other items suspended to blow in the 

U.S. Department of Agriculture Page 5
breeze. As with the other items mentioned above, unless 

birds recognize the object as a threat to their safety, they 

will ignore it or in some cases make use of a device. For 

example, gulls may incorporate Mylar flags within their 

nesting material.

Kites or balloon/kite combinations that take the form of 

simulated predators (Figure 3) have been reported to deter 

birds successfully from some areas, and they provide an 

option in areas that regulate noise levels from acoustic 

bird deterrents. However, kites and balloon/kite 

combinations are labor intensive to use, may be limited by 

weather conditions, and have a shrinking sphere of 

influence as birds habituate to them unless other 

techniques also are used. 

Auditory-Visual Techniques

Remote controlled vehicles, including boats and aircraft, 

have successfully scared birds because they can be 

deployed in a threatening manner. Using these requires a 

level of skill (especially for aircraft), time and money to 

develop. Weather conditions may limit their use. 

Dogs have been used successfully to disperse birds, 

especially waterfowl in urban and suburban areas (Figure 

4). Properly trained dogs provide motivated harassment 

that birds recognize as threats. Dogs can be trained to 

remain within a given area and in some cases may be 

housed there to provide constant control. Dog handlers are 

required when dogs are taken to various sites where they 

chase away targeted birds. Birds often return after the 

dogs leave the site. Even where dogs remain, they may 

lose interest in chasing the birds; this allows birds to return 

to the site. As with any bird dispersal technique, dogs are 

most effective when used with other control activities.

Falconry, the use of live raptors under the control of a 

handler, has been used in a variety of places to scare birds 

away. Many raptors present an innate threat to birds, 

which either hide or disperse when a raptor is visible and 

hunting. Falconry is expensive and requires extensive 

training, permits are required, multiple raptors are needed 

to cover large areas, weather conditions can restrict when 

raptors can fly, and dedicated personnel are necessary to 

make a system work. Due to some of the limitations 

inherent with a falconry program, other techniques to 

frighten birds should be integrated into any falconry 

program.

Compressed air may be used directly or indirectly to 

displace birds from roosting, loafing, or feeding areas. Air 

blown directly onto birds through a tube or hose may 

initially force them to move. Compressed air may be used 

indirectly by causing hoses to move erratically within sight 

of the birds. Air forced through lightweight hoses causes 

them to move unpredictably, making birds avoid the area. 

Some birds, however, quickly learn to vacate the protected 

area temporarily when they hear the noise of the air 

compressor or air coming out of the tube, only to return 

when the air is turned off. As with other devices, birds may 

learn to avoid only the points where the air or hoses are 

applied, therefore air or hoses should be used as part of an 

integrated system.

High-pressure water sprayers have been used effectively to 

disperse roosts. Some birds learn to associate the sound 

of the sprayer pump with being sprayed and will leave the 

roost before being sprayed. If the sprayer cannot reach 

portions of the roost due to dense vegetation and other 

obstructions, use other scare devices as well. 

Figure 3. Balloons that have features similar to predators may frighten birds.

Page 6 WDM Technical Series—Bird Dispersal
Repellents

Most chemical bird repellents are irritants. Avitrol® (4-

aminopyridine) is listed by the U.S. Environmental Protection Agency as a chemical frightening agent, although the 

chemical is lethal to any birds that ingest it. Before dying, 

affected birds make distress calls, engage in irregular 

flight, and/or show other signs of distress that frighten the 

rest of the flock away from the area. 

Polybutene-based products are marketed as tactile repellents. When in contact with the feet of birds, these products make them uncomfortable. Gels, tars, or similar material should be used with caution because some break down 

in high heat and stain or run. They are less effective when 

dirt or other material coat the surface of the products.

Application of repellents to grass can help disperse birds 

from areas where they are a problem. A variety of products 

are available on the market, but only two active ingredients, methyl anthranilate (MA) or anthraquinone (AQ), are 

registered for use on turf. Products that have MA elicit an 

immediate response, as MA is a chemical irritant that produces pain when it contacts the eyes, nostrils, or mouths 

of birds. Products containing AQ are secondary repellents 

because birds experience intestinal discomfort after eating 

treated food and then associate the food with the discomfort, leading to avoidance of the food. In controlled studies, 

both MA and AQ have shown promise as bird repellents, 

although results have been mixed since repellency is impacted by a variety of factors such as availability of alternative food, distance to escape cover, or weather. Additionally, because changes in formulation and application techniques may affect efficacy of repellents, applicators should 

check current literature to determine if their intended application is likely to succeed.

MA also may be used as an irritant when it is used as the 

active ingredient in foggers. A bird that contacts MA 

through its nose, eyes, or mouth experiences distress and 

often leaves the area to avoid the chemical. Napthalene 

(moth balls or moth flakes) has been suggested as a 

means to keep birds from enclosed areas, but when tested, birds (especially starlings) were not discouraged from 

using treated sites. 

Sulfur-based products repel mammals, but their effectiveness as bird repellents is unclear. Snow geese (Chen caerulescens) appear to avoid fields treated with high concentrations of the sulfur-based Deer Away® Big Game Repellent, but starlings were not deterred from nest boxes treated with the same product.

Urban Crow Roost Management

Thousands of American crows may congregate in urban 

winter roosts that create large amounts of fecal contamination of walkways, cars, and other property, as well as nightlong cacophony. In some instances, as many as 70,000 

crows have been recorded in a single winter roost. Before 

efforts at reducing the impact of the crows begins, it is critical to set an objective that all parties within the affected 

area agree with. In the case of crow roosts, the objective 

may be to splinter the flock into small groups, or to move 

the crows to alternate areas largely uninhabited by people. 

It also is necessary to be sure that the birds are not moved 

to an area in which they could become a significant threat 

to human health and safety (e.g., moving birds into areas 

with increased risk of striking aircraft or vehicles).

Page 7

Figure 4. Border collie herding Canada geese (Branta canadensis).

U.S. Department of Agriculture

Bird Management Examples
Dispersing urban crow roosts requires coordination from 

multiple entities, including city management, law 

enforcement, public relations, and the agency conducting 

the work. The media are likely to be interested, and it is 

wise to provide a media spokesperson on the first night of 

harassment. 

A combination of tools such as recorded crow distress calls 

played through loud speakers, pyrotechnics, red-beam 

lasers designed for bird harassment, and spotlights can be 

used to break up roosts. During the first few days of the 

roost dispersal program, biologists and technicians should 

set up any specialized equipment at the principal crow 

roost before the crows begin to arrive at dusk. As the flock 

begins to trickle in, use a battery of tools to harass (scare 

away) the crows. Visit the principle roost each night until 

the birds abandon the site or splinter into smaller roosts 

(usually after 5 to 10 nights). During the first winter or two 

of roost dispersal at the main sites, it may be necessary to 

conduct routine hazing every night for several weeks. Once 

the crows abandon the original roosting site, hazing may 

be reduced to several nights every 2 to 3 weeks. 

Beginning with the first night of hazing, it is important that 

mobile teams drive through nearby neighborhoods to 

search for the formation of new roosting locations. When 

pursued and harassed, crows tend to seek the cover of 

coniferous trees. Because they can hide more easily in 

pines, listening for crows can be as effective as visual 

searches. Once a roosting location is found, you can use 

the same tools to harass the crows until they disperse. 

Encourage residents to report the locations of crow roosts 

directly to the agency conducting the work. Persistence is 

fundamental to a successful management of urban crow 

roosts. 

Urban Canada Goose Management

Canada geese, when congregating in large numbers within 

public areas or on lawns, can create problems due to their 

droppings and, in some cases, their aggressive behavior 

towards people. All concerned parties should agree on the 

goal(s) of any management program before it is initiated. In 

the case of a non-lethal control program, the goal simply 

may be to reduce but not eliminate all geese within the 

area. Studies have shown that when local geese are 

harassed, they often travel less than 2 kilometers (11⁄4 

miles) from the site and regularly return within hours of 

harassment. 

Once objectives have been determined, a goose 

harassment program should use a number of methods, 

such as chases by border collies, remote control boats, 

kayak chases, and pyrotechnics. Goose behavior, and the 

effectiveness of any control program, is dependent on 

breeding condition, migration, and molt. A pair of geese is 

much more difficult to scare away once an active nest is 

established. Trained personnel must visit each site of 

concern multiple times each week from May through 

October to prevent habitual use by geese. Initially, multiple 

visits each day are necessary to ensure that geese do not 

return. When conducting the hazing program, make sure 

that all geese have left the area and do not merely circle 

back to the site. If the person hazing leaves too quickly, the 

geese will return within minutes. Geese always should be 

hazed away from busy roadways or airports. 

Curious bystanders often inquire about the hazing. When 

using a dog, it is helpful to fit the dog with a flotation vest 

with a logo or other marking that will let people know that 

the dog and hazer are authorized and will prevent the dog 

from tiring as quickly when swimming. 

Repeat non-lethal goose management as often as 

necessary from year to year to make the site as 

inhospitable as possible to the geese. No-feeding 

ordinance, low fencing or wires around ponds, and 

vegetation or rip rap at the water’s edge can enhance the 

effectiveness of goose harassment efforts. 

Bird dispersal techniques are a vital part of safely and 

efficiently reducing bird conflicts with humans. The bird 

must perceive a technique as a threat if it is to be 

effective. No single technique can solve all bird conflicts, 

but an integrated use of multiple techniques, each 

enhancing the other, generally provides relief. When 

Page 8 WDM Technical Series—Bird Dispersal

Conclusion
possible, decreasing the attractiveness of the site by removal of food, water, or shelter helps to reduce conflicts as 

well as enhance the effectiveness of dispersal tools. Engaging municipal leaders and public agencies facilitates 

obtaining permissions, special authorities, and budgetary 

decisions from communities and organizations. Municipal 

leaders also can aid in establishing no-feed ordinances 

and positive public relations. Ultimately, the skill, 

knowledge, and persistence of those charged with reducing the conflict, and patience of the public will play a key 

role in successfully dispersing birds.

U.S. Department of Agriculture Page 9
Page 10

Acknowledgements

Figure 1. Photo by T.W. Seamans, USDA-APHIS-WS and Reconyx

Figure 2. Photo by Stephen M. Vantassel

Figure 3. Photo by John Humphrey, USDA-APHIS-WS

Figure 4. Photo by Stephen M. Vantassel

We thank Thurman Booth for establishing the basis for this manuscript and J. Cepek, T. DeVault, and B. 

Washburn for their reviews.

Glossary

Bioacoustics: The study of biological sounds that combines 

the fields of biology and acoustics. 

Effigies: A three-dimensional figure or dummy of a person 

or animal

Habituate: A degradation in response to repeated stimulation such that the animal no longer reacts to the deployment of a scare tactic.

Innate: Existing in, belonging to, or determined by factors 

present in an individual from birth. 

Neophobic: The tendency of an animal to avoid or retreat 

from an unfamiliar object or situation. 

Ultrasonic: Of or relating to acoustic frequencies above the 

range audible to the human ear (above approximately 

20,000 hertz).

Key Words

Auditory techniques, Chemical techniques, Frightening 

techniques, Habitat modification, Scare tactics, Visual 

techniques

Disclaimer

Wildlife can threaten the health and safety of you and others in the area. Use of damage prevention and control 

methods also may pose risks to humans, pets, livestock, 

other non-target animals, and the environment. Be aware 

of the risks and take steps to reduce or eliminate those 

risks. 

Some methods mentioned in this document may not be 

legal, permitted, or appropriate in your area. Read and follow all pesticide label recommendations and local requirements. Check with personnel from your state wildlife agency and local officials to determine if methods are acceptable and allowed. 

Mention of any products, trademarks, or brand names 

does not constitute endorsement, nor does omission constitute criticism. 

WDM Technical Series—Bird Dispersal

Citation

Seamans, T.W. and A. Gosser. 2016. Bird dispersal 

techniques. Wildlife Damage Management Technical 

Series. USDA, APHIS, WS National Wildlife Research 

Center. Ft. Collins, Colorado. 12p. 
Page 11

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