Presentation on theme: "Identification and Management of Wildlife Damage Kurt C. VerCauteren, Richard A. Dolbeer, and Eric M. Gese."— Presentation transcript:
Identification and Management of Wildlife Damage Kurt C. VerCauteren, Richard A. Dolbeer, and Eric M. Gese
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
Wildlife Damage Management Must Be... ► Based on sound economic, ecological, and sociological principles ► Carried out as positive, necessary components of wildlife management programs Actions must be justified, environmentally safe, humane, and in the public interest
Four Principle Components (1) Problem definition Species causing problem Number of animals Amount of loss Nature of conflict (2) Ecology of the problem species 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
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 a depredation permit be obtained before most migratory birds can before most migratory birds can be captured, killed, possessed, or be captured, killed, possessed, or transported to control transported to control depredation depredation
Examples of Damage by Birds SpeciesDamage GullsAviation safety, Building damage, Nuisance Blackbirds, StarlingsAviation safety, Crops (corn, sunflower, rice), Nuisance Pigeons, House SparrowsGrain contamination, Building Damage Crows, Ravens, MagpiesPredation (birds, livestock), Crops (corn, fruit), Nuisance Herons, Egrets, CormorantsCommercial and natural fisheries RaptorsAviation safety, Predation (poultry, livestock) WoodpeckersDamage to wooden structures, Nuisance Ducks, Geese, Sandhill Cranes Aviation safety, Crops, Nuisance
Examples of Control Techniques for Birds ► Habitat Modification and Cultural Practices ► Netting and Screening ► Frightening Devices ► Repellents ► Toxicants and Capture Agents
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
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 45 o to deter perching ► Spikes and electric wires can be used to deter perching ► Overhead monofilament lines monofilament lines can be used to can be used to deter many bird deter many bird species species
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
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
Examples of Ungulate Damage SpeciesDamage Cervids (deer, elk)Aviation and vehicle safety, crops (soybean, corn, alfalfa, stored ), trees, urban landscapes, and disease Feral swineCrops, pasture, yards, and native habitat
Examples of Control Techniques for Ungulates ► Habitat and Food Modification ► Fencing and Barriers ► Frightening and Hazing ► Dogs as Deterrents ► Repellents ► Fertility Control ► Lethal control Regulated hunting Sharp shooting
Lethal Control ► Regulated managed hunting is the most practical and effective method of management ► Is the most ecologically, socially, and fiscally responsible method
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
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
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
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
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
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
Examples of Control Techniques ► Habitat Modification ► Cultural Practices ► Exclusion ► Frightening Devices ► Removal ► Biological Management ► Fertility Control ► Repellents ► Fumigants ► Toxicants
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
Exclusion ► Installation of barriers that prevent access to structures or areas, or eliminate contact with specific objects ► “Rodent proofing”
Biological Management and Fertility Control ► Biological Management: 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.
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
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
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 Shooting may be used to selectively eliminate some pest mammals selectively eliminate some pest mammals Live traps are often used to capture mammals of all sizes
Examples of Damage by Carnivores and Other Mammalian Predators SpeciesDamage BadgerSmall Mammals, Birds, Lambs, Poultry, Burrowing Black & Grizzly BearLivestock, Field crops, Beehives, Nuisance, Trees Coyote, Wolves, DogsPredation (livestock, big game, poultry), Fruit crops Mountain Lion, Bobcat, LynxPredation (livestock, horses, big game, poultry, pets) FoxesPredation (small mammals, livestock, poultry), Fruit crops OpossumsPredation (poultry), Nuisance RaccoonsPredation (poultry, livestock, small vertebrates, birds), Crops (corn), Nuisance SkunksPredation (waterfowl, poultry), Nuisance Weasels & MinkPredation (poultry, small vertebrates, birds, fish) Feral CatsPredation (songbirds, small vertebrates)
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.
Examples of Control Techniques for Carnivores ► Livestock Husbandry Practices ► Guard Dogs ► Guard Llamas ► Guard Donkeys ► Fencing and Barriers ► Frightening Devices ► Repellents and Aversive Conditioning Conditioning ► Reproductive Interference ► Relocation ► Financial Incentives ► Livestock Protection Collars ► M-44s ► Aerial Hunting ► Trapping ► Calling and Shooting ► Hunting with hounds ► Snares
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
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
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
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 the electric fence on the species being protected species being protected must be considered. must be considered. Burying wire mesh Burying wire mesh helps prevent predators helps prevent predators from digging into an area. from digging into an area.
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.
Repellents and Aversive Conditioning ► Repellents 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
Reproductive Interference and Relocation of Problem Animals Reproductive Interference ► 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 spec ies
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
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
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
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.
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
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.
Hunting 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 ► Trail hounds Redbone, Walker, Bluetick, Black & Tan Hunt by scent in packs ► Sight hounds Greyhound Most effective in open terrain
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
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.