1. Identification and Management of Wildlife Damage
Kurt C. VerCauteren, Richard A. Dolbeer, and Eric M. Gese

2. Wildlife Damage Management
Wildlife Damage in the US
Cost is ~ $22 billion annually
Control is important due to
Expanding human populations
Intensified land-use practices

3. Wildlife Damage Management Must Be . . .
Based on sound economic, ecological, and sociological principles
Carried out as positive, necessary components of wildlife management programs
Inset photo
Actions must be justified, environmentally safe, humane, and in the public interest

4. Four Principle Components
(1) Problem definition
Species causing problem
Number of animals
Amount of loss
Nature of conflict
(2) Ecology of the
problem species
(3) Management methods
application
Develop an appropriate management strategy using (1) and (2)
(4) Evaluation of
management effort
Assess the results relative to cost and impact on target and non-target populations

5. Legal Requirements for Management
It is important to understand the laws regarding target and non-target species
Capture, possession, or killing of most mammals, reptiles, and amphibians is regulated by state or provincial laws
Federal regulations require that
a depredation permit be obtained
before most migratory birds can
be captured, killed, possessed, or
transported to control
depredation
Insert photo of whooping crane

6. Examples of Damage by Birds
Species
Damage
Gulls
Aviation safety, Building damage, Nuisance
Blackbirds, Starlings
Aviation safety, Crops (corn, sunflower, rice), Nuisance
Pigeons, House Sparrows
Grain contamination, Building Damage
Crows, Ravens, Magpies
Predation (birds, livestock), Crops (corn, fruit), Nuisance
Herons, Egrets, Cormorants
Commercial and natural fisheries
Raptors
Aviation safety, Predation (poultry, livestock)
Woodpeckers
Damage to wooden structures, Nuisance
Ducks, Geese, Sandhill Cranes
Aviation safety, Crops, Nuisance

7. Examples of Control Techniques for Birds
Habitat Modification and Cultural Practices
Netting and Screening
Frightening Devices
Repellents
Toxicants and Capture Agents

8. Habitat Modification and Cultural Practices
Can be implemented to make roosting, loafing, or feeding sites less attractive
Lure crops may be used to control waterfowl or blackbirds.
Bird-resistant crops may also be used to limit losses

9. Proofing and Screening
Plastic netting to protect crops
Netting or wire screening may be used to exclude birds from building structures
Building ledges can be angled 45o to deter perching
Spikes and electric wires can be used to deter perching
Overhead
monofilament lines
can be used to
deter many bird
species

10. Frightening Devices No device is 100% effective
Birds quickly habituate
Propane cannons
Pyrotechnics
Recorded alarm / distress calls
Flags, kites, and helium balloons
Strobe lights
Ultrasonic devices

11. Repellents, Toxicants, and Capture Agents
Repellents based on smell and taste are generally ineffective
Condition-aversive repellents are more effective
Produce illness or adverse physiological responses upon ingestion
Toxicants and capture agents require knowledge of the habits and food preferences of the target species
DRC-1339: used to control starlings, gulls
Avitrol: frightening agent used to control pigeons, gulls, house sparrows, starlings, blackbirds
Alpha-chloralose: used to capture waterfowl and pigeons

12. Examples of Ungulate Damage
Species
Damage
Cervids (deer, elk)
Aviation and vehicle safety, crops (soybean, corn, alfalfa, stored ), trees, urban landscapes, and disease
Feral swine
Crops, pasture, yards, and native habitat

13. Examples of Control Techniques for Ungulates
Lethal control
Regulated hunting
Sharp shooting
Habitat and Food Modification
Fencing and Barriers
Frightening and Hazing
Dogs as Deterrents
Repellents
Fertility Control

14. Lethal Control
Regulated managed hunting is the most practical and effective method of management
Is the most ecologically, socially, and fiscally responsible method

15. Habitat and Food Modification
Select unpalatable/ resistant plants
Reduce permanent cover
Harvest crops as soon as ripe
Lure crops / Baiting
In some situations these may actually increase local damage

16. Exclusion: Fencing and Barriers
Fencing can be a long-term, nonlethal control method. Fencing provides protection by acting as a physical barrier and/or psychological barrier
Variables to consider: level of protection desired, seasonality of the resource being protected, physical ability of the target species, motivation to breach, behavioral characteristics, cost, longevity of materials, potential negative effects

17. Frightening and Hazing
Ungulates habituate quickly
Many marketed devices do not work
Devices that target multiple senses are the most efficacious
Persistent hazing can be effective
Dogs may be used as deterrents

18. Repellents Limited effectiveness
Odor repellents: designed to repel animals, and either mimic predator odors or are repugnant
Contact repellents are applied directly to the target resources and change the hedonic quality of the item, and/or cause illness (aversive conditioning)
Systemic repellents: are incorporated into plants naturally, by supplementation, or genetic manipulation

19. Fertility Control
Wildlife contraceptives have the potential to be complimentary management tools, however; it is unlikely that fertility control will become a stand-alone management strategy
Methods include chemosterilants, intrauterine devices, immunocontraceptives, and surgery
Recent developments include single-shot fertility control methods, orally delivered contraceptives, viral- or bacterial-vectored delivery methods

20. Examples of Damage by Rodents and Small Mammals
Species
Damage
Beaver, Muskrat, Nutria
Waterways, Wetlands, Trees, Crops (rice, sugarcane)
Deer & White-footed mice
Seed predation, Crops, Home invasion
Ground Squirrel
Pasture, Rangeland, Gardens, Crops (forage, grain, fruit, nut)
Marmots
Burrowing, Gardens, Crops (alfalfa, soybean, vegetables, fruit)
Voles
Trees, Shrubs, Crops (field & garden)
Moles
Burrowing (turf, pasture, crop fields)
Pocket gopher
Burrowing, Crops (field, root), Trees, Pasture
Prairie Dog
Burrowing, Crops, Grasslands, Crops
Rabbits & Hares
Landscape plantings, Gardens, Crops, Rangeland, Trees, Shrubs
Tree Squirrels
Trees, Shrubs, Plantings, Nuisance, Power lines
Woodrats
Fruit, Seed Crops, Herbaceous & Woody Plants, Nuisance
Commensal rodents
Grain Crops, Birds, Livestock, Property damage, Burrowing

21. Rodents and Other Small Mammals
Damage is frequently difficult to measure; most species are nocturnal and not easily observed. Characteristics of damage may provide clues. Quantification of damage is often made by comparing the damaged site with an undamaged area, then converting the losses to dollars.
Damage to plants may be generally grouped as:
Root damage
Trunk debarking
Stem & branch cutting
Needle clipping
Debudding

22. Examples of Control Techniques
Habitat Modification
Cultural Practices
Exclusion
Frightening Devices
Removal
Biological Management
Fertility Control
Repellents
Fumigants
Toxicants

23. Habitat Modification and Cultural Practices
Elimination of food and shelter
Remove brush, debris, woodpiles, garbage, refuse, tall vegetation
Mechanical devices
Provision of alternative foods
Remove insect and invertebrate food supplies

24. Exclusion
Installation of barriers that prevent access to structures or areas, or eliminate contact with specific objects
“Rodent proofing”

25. Biological Management and Fertility Control
Introduction of agents of disease and predatory species. Be careful, historically has led to dire unintended consequences (e.g., mongoose).
Fertility Control:
In time may be an effective supplemental tool. Oral and immunological agents are being developed as are viral-vectored immunocontraceptives.

26. Repellents Repellents are most effective when applied to foods
Several compounds are registered for use, however; efficacy data is often lacking
Chemical repellents include:
Sensory repellents
Semiochemical odors
Taste avoidance behavior compounds

27. Fumigants and Toxicants
Fumigants are used for lethal control of burrowing mammals. Examples include smoke-producing gas cartridges, aluminum phosphide, choloropicrin, and methyl bromide
Toxicants are labor and cost efficient, and are the most commonly used method of control. Potential hazards to non-target wildlife must be considered prior to use. Two types of toxicants are commonly used
Anit-coagulants
Non-anti-coagulants

28. Removal
Foothold traps are commonly used to trap beaver, muskrat, and nutria; smaller sizes are used to capture small mammals. Body gripping traps are used for beaver, muskrat, nutria, moles and pocket gophers. Snap traps are typically used to control rats and mice. Snares may be used to capture or kill beaver, rabbits, and other animals.
Shooting may be used to
selectively eliminate some pest mammals
Live traps are often used to capture mammals of all sizes

29. Examples of Damage by Carnivores and Other Mammalian Predators
Species
Damage
Badger
Small Mammals, Birds, Lambs, Poultry, Burrowing
Black & Grizzly Bear
Livestock, Field crops, Beehives, Nuisance, Trees
Coyote, Wolves, Dogs
Predation (livestock, big game, poultry), Fruit crops
Mountain Lion, Bobcat, Lynx
Predation (livestock, horses, big game, poultry, pets)
Foxes
Predation (small mammals, livestock, poultry), Fruit crops
Opossums
Predation (poultry), Nuisance
Raccoons
Predation (poultry, livestock, small vertebrates, birds), Crops (corn), Nuisance
Skunks
Predation (waterfowl, poultry), Nuisance
Weasels & Mink
Predation (poultry, small vertebrates, birds, fish)
Feral Cats
Predation (songbirds, small vertebrates)

30. Carnivores and Other Mammalian Predators
Livestock depredation has been a concern to livestock producers for centuries. Accurate assessment of a predation event requires careful observation. Signs of predation and the possible predator involved should be searched for on the prey item and around the kill site. Scavenging should not be confused with predation.

31. Examples of Control Techniques for Carnivores
Livestock Husbandry Practices
Guard Dogs
Guard Llamas
Guard Donkeys
Fencing and Barriers
Frightening Devices
Repellents and Aversive
Conditioning
Reproductive Interference
Relocation
Financial Incentives
Livestock Protection Collars
M-44s
Aerial Hunting
Trapping
Calling and Shooting
Hunting with hounds
Snares

32. Livestock Husbandry Practices
Confine or concentrate herds
Use of herders
Shed lambing/ calving
Remove dead livestock
Synchronized birthing
House young livestock in areas with little cover, and in proximity to humans

33. Guard Dogs
Studies investigating the efficacy of guard dogs have shown the dogs to be effective in some situations. Efficacy decreases in areas of thick cover, or when large flocks are dispersed over rough terrain
Use of guard dogs precludes the use of other control devices such as traps, snares, or toxicants

34. Guard Llamas and Guard Donkeys
Llamas can be a practical and effective technique to deter predators (especially coyotes and dogs)
Donkeys may also be used as livestock guardians against coyotes and dogs. They are most effective in small, fenced pastures

35. Fencing and Barriers
Barriers include flagging, exclosures, electric fence, nest screen, moats.
Fencing is best suited for protecting small areas. Standard fencing will not always deter predators. Adding electric fence along, or above the fence improves efficacy, however; the effect of
the electric fence on the
species being protected
must be considered.
Burying wire mesh
helps prevent predators
from digging into an area.

36. Frightening Devices Lights Distress calls Loud noises Scarecrows
Plastic streamers
Propane cannons
Radio Activated Guard (RAG) device
Motion Activated Guard (MAG) device
All of these devices provide temporary relief only. Changing the location, pattern of disruption, or combining techniques may prolong the success.
Light may be the most important component of the frightening device.

37. Repellents and Aversive Conditioning
There are no commercially available repellents that effectively deter predation
Aversive conditioning
Use of lithium chloride may reduce consumption of prey, but does not deter predation in coyotes
May be effective in “teaching” black bears to fear and avoid humans

38. Reproductive Interference and Relocation of Problem Animals
Presently there are no species-specific reproductive control measures, although use of immunocontraceptive agents has been investigated.
Vasectomization of coyotes and wolves has been investigated as well.
Relocation
Relocation programs have had limited success with bears and wolves
Relocation efforts are expensive, but are considered worthwhile and necessary in the management of endangered species

39. Financial Incentives
Assessment of local economic and ecologic conditions should be performed before implementing a compensation program. Incentives may be best realized if tied to conservation outcomes
“Predator Friendly Products” which come from ranches that do not kill predators
Problems with compensation programs:
Producers feel they don’t receive fair market value
Compensation is not paid for “missing” animals
Compensation doesn’t encourage correction of poor management practices

40. Livestock Protection Collar
The collar fits around the neck of lambs and kid goats, and contains bladders filled with 1080 (an acute toxicant). It is is designed to kill coyotes when they puncture a bladder during a predatory attack.
Advantage:
Selective removal of problem animals
Disadvantage:
Cost & labor
Accidental puncture of the bladders

41. M-44
A mechanical device that injects sodium cyanide into the mouth of an animal when it bites/pulls on the device
M-44 is registered and authorized by different agencies depending on the country of use for coyotes, foxes, and feral dogs
Disadvantages:
Not species specific
Does not always remove the problem animal
Numerous use restrictions

42. Aerial Hunting
Fixed- and rotary-wing aircraft are commonly used in control programs for wolves, coyotes, bobcats, and foxes. Hunting is most effective with snow cover
Federal law requires each state where aerial hunting is allowed to issue aerial hunting permits. Some states also require low-level flying waivers.

43. Traps Cage traps can be used to capture predators of all sizes
Foothold traps are more effective and available in various sizes
Most states have regulations on types of traps, baits, sets, and trap visitation schedules. Some states no longer allow foothold traps. Consult state and local regulations prior to conducting any trapping activity

44. Calling and Shooting
Can be a selective means to control coyotes, bobcats, and foxes. Commercial and recorded calls mimic the sound of a rabbit in distress or a pup in distress. Morning and late afternoon are the most effective times to employ calling, although calling at night and using a spotlight (where legal) may be effective as well.

45. Hunting Hounds Sight hounds Trail hounds
Hunting dogs are used for lethal control. State and local laws should be consulted prior to pursuing carnivors with dogs. Two types of dogs are commonly used
Sight hounds
Greyhound
Most effective in open terrain
Trail hounds
Redbone, Walker, Bluetick, Black & Tan
Hunt by scent in packs

46. Snares
Constructed of wire or cable looped through a locking device that allows the snare to tighten
Two types:
Body snares are used primarily on coyotes and foxes, in areas where the predator crawls under a fence, at a den entrance, or in a narrow passageway
Spring activated foot snares are used to capture large predators

47. SUMMARY
Wildlife Damage Management is an increasingly important part of the wildlife profession because of expanding human populations, intensified land-use practices, increasing prominence of wildlife vectoring disease, and other reasons.
Many species at one time or another require management actions to reduce conflicts with people, livestock, or other wildlife species.
There are few “silver bullet” easy remedies.
Integrated Wildlife Damage Management Strategies, using a variety of techniques to dynamically target problem individuals or species are usually preferred and most effective for long-term management.