Presentation on theme: "Identification and Management of Wildlife Damage"— Presentation transcript:
1Identification and Management of Wildlife Damage Kurt C. VerCauteren, Richard A. Dolbeer, and Eric M. Gese
2Wildlife Damage Management Wildlife Damage in the USCost is ~ $22 billion annuallyControl is important due toExpanding human populationsIntensified land-use practices
3Wildlife Damage Management Must Be . . . Based on sound economic, ecological, and sociological principlesCarried out as positive, necessary components of wildlife management programsInset photoActions must be justified, environmentally safe, humane, and in the public interest
4Four Principle Components (1) Problem definitionSpecies causing problemNumber of animalsAmount of lossNature of conflict(2) Ecology of theproblem species(3) Management methodsapplicationDevelop an appropriate management strategy using (1) and (2)(4) Evaluation ofmanagement effortAssess the results relative to cost and impact on target and non-target populations
5Legal Requirements for Management It is important to understand the laws regarding target and non-target speciesCapture, possession, or killing of most mammals, reptiles, and amphibians is regulated by state or provincial lawsFederal regulations require thata depredation permit be obtainedbefore most migratory birds canbe captured, killed, possessed, ortransported to controldepredationInsert photo of whooping crane
6Examples of Damage by Birds SpeciesDamageGullsAviation safety, Building damage, NuisanceBlackbirds, StarlingsAviation safety, Crops (corn, sunflower, rice), NuisancePigeons, House SparrowsGrain contamination, Building DamageCrows, Ravens, MagpiesPredation (birds, livestock), Crops (corn, fruit), NuisanceHerons, Egrets, CormorantsCommercial and natural fisheriesRaptorsAviation safety, Predation (poultry, livestock)WoodpeckersDamage to wooden structures, NuisanceDucks, Geese, Sandhill CranesAviation safety, Crops, Nuisance
7Examples of Control Techniques for Birds Habitat Modification and Cultural PracticesNetting and ScreeningFrightening DevicesRepellentsToxicants and Capture Agents
8Habitat Modification and Cultural Practices Can be implemented to make roosting, loafing, or feeding sites less attractiveLure crops may be used to control waterfowl or blackbirds.Bird-resistant crops may also be used to limit losses
9Proofing and Screening Plastic netting to protect cropsNetting or wire screening may be used to exclude birds from building structuresBuilding ledges can be angled 45o to deter perchingSpikes and electric wires can be used to deter perchingOverheadmonofilament linescan be used todeter many birdspecies
10Frightening Devices No device is 100% effective Birds quickly habituatePropane cannonsPyrotechnicsRecorded alarm / distress callsFlags, kites, and helium balloonsStrobe lightsUltrasonic devices
11Repellents, Toxicants, and Capture Agents Repellents based on smell and taste are generally ineffectiveCondition-aversive repellents are more effectiveProduce illness or adverse physiological responses upon ingestionToxicants and capture agents require knowledge of the habits and food preferences of the target speciesDRC-1339: used to control starlings, gullsAvitrol: frightening agent used to control pigeons, gulls, house sparrows, starlings, blackbirdsAlpha-chloralose: used to capture waterfowl and pigeons
12Examples of Ungulate Damage SpeciesDamageCervids (deer, elk)Aviation and vehicle safety, crops (soybean, corn, alfalfa, stored ), trees, urban landscapes, and diseaseFeral swineCrops, pasture, yards, and native habitat
13Examples of Control Techniques for Ungulates Lethal controlRegulated huntingSharp shootingHabitat and Food ModificationFencing and BarriersFrightening and HazingDogs as DeterrentsRepellentsFertility Control
14Lethal ControlRegulated managed hunting is the most practical and effective method of managementIs the most ecologically, socially, and fiscally responsible method
15Habitat and Food Modification Select unpalatable/ resistant plantsReduce permanent coverHarvest crops as soon as ripeLure crops / BaitingIn some situations these may actually increase local damage
16Exclusion: Fencing and Barriers Fencing can be a long-term, nonlethal control method. Fencing provides protection by acting as a physical barrier and/or psychological barrierVariables 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
17Frightening and Hazing Ungulates habituate quicklyMany marketed devices do not workDevices that target multiple senses are the most efficaciousPersistent hazing can be effectiveDogs may be used as deterrents
18Repellents Limited effectiveness Odor repellents: designed to repel animals, and either mimic predator odors or are repugnantContact 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
19Fertility ControlWildlife contraceptives have the potential to be complimentary management tools, however; it is unlikely that fertility control will become a stand-alone management strategyMethods include chemosterilants, intrauterine devices, immunocontraceptives, and surgeryRecent developments include single-shot fertility control methods, orally delivered contraceptives, viral- or bacterial-vectored delivery methods
21Rodents 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 damageTrunk debarkingStem & branch cuttingNeedle clippingDebudding
22Examples of Control Techniques Habitat ModificationCultural PracticesExclusionFrightening DevicesRemovalBiological ManagementFertility ControlRepellentsFumigantsToxicants
23Habitat Modification and Cultural Practices Elimination of food and shelterRemove brush, debris, woodpiles, garbage, refuse, tall vegetationMechanical devicesProvision of alternative foodsRemove insect and invertebrate food supplies
24ExclusionInstallation of barriers that prevent access to structures or areas, or eliminate contact with specific objects“Rodent proofing”
25Biological 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.
26Repellents Repellents are most effective when applied to foods Several compounds are registered for use, however; efficacy data is often lackingChemical repellents include:Sensory repellentsSemiochemical odorsTaste avoidance behavior compounds
27Fumigants and Toxicants Fumigants are used for lethal control of burrowing mammals. Examples include smoke-producing gas cartridges, aluminum phosphide, choloropicrin, and methyl bromideToxicants 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 usedAnit-coagulantsNon-anti-coagulants
28RemovalFoothold 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 toselectively eliminate some pest mammalsLive traps are often used to capture mammals of all sizes
29Examples of Damage by Carnivores and Other Mammalian Predators SpeciesDamageBadgerSmall Mammals, Birds, Lambs, Poultry, BurrowingBlack & Grizzly BearLivestock, Field crops, Beehives, Nuisance, TreesCoyote, Wolves, DogsPredation (livestock, big game, poultry), Fruit cropsMountain Lion, Bobcat, LynxPredation (livestock, horses, big game, poultry, pets)FoxesPredation (small mammals, livestock, poultry), Fruit cropsOpossumsPredation (poultry), NuisanceRaccoonsPredation (poultry, livestock, small vertebrates, birds), Crops (corn), NuisanceSkunksPredation (waterfowl, poultry), NuisanceWeasels & MinkPredation (poultry, small vertebrates, birds, fish)Feral CatsPredation (songbirds, small vertebrates)
30Carnivores 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.
31Examples of Control Techniques for Carnivores Livestock Husbandry PracticesGuard DogsGuard LlamasGuard DonkeysFencing and BarriersFrightening DevicesRepellents and AversiveConditioningReproductive InterferenceRelocationFinancial IncentivesLivestock Protection CollarsM-44sAerial HuntingTrappingCalling and ShootingHunting with houndsSnares
32Livestock Husbandry Practices Confine or concentrate herdsUse of herdersShed lambing/ calvingRemove dead livestockSynchronized birthingHouse young livestock in areas with little cover, and in proximity to humans
33Guard DogsStudies 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 terrainUse of guard dogs precludes the use of other control devices such as traps, snares, or toxicants
34Guard 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
35Fencing and BarriersBarriers 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 ofthe electric fence on thespecies being protectedmust be considered.Burying wire meshhelps prevent predatorsfrom digging into an area.
36Frightening Devices Lights Distress calls Loud noises Scarecrows Plastic streamersPropane cannonsRadio Activated Guard (RAG) deviceMotion Activated Guard (MAG) deviceAll 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.
37Repellents and Aversive Conditioning There are no commercially available repellents that effectively deter predationAversive conditioningUse of lithium chloride may reduce consumption of prey, but does not deter predation in coyotesMay be effective in “teaching” black bears to fear and avoid humans
38Reproductive 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.RelocationRelocation programs have had limited success with bears and wolvesRelocation efforts are expensive, but are considered worthwhile and necessary in the management of endangered species
39Financial IncentivesAssessment 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 predatorsProblems with compensation programs:Producers feel they don’t receive fair market valueCompensation is not paid for “missing” animalsCompensation doesn’t encourage correction of poor management practices
40Livestock 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 animalsDisadvantage:Cost & laborAccidental puncture of the bladders
41M-44A mechanical device that injects sodium cyanide into the mouth of an animal when it bites/pulls on the deviceM-44 is registered and authorized by different agencies depending on the country of use for coyotes, foxes, and feral dogsDisadvantages:Not species specificDoes not always remove the problem animalNumerous use restrictions
42Aerial HuntingFixed- and rotary-wing aircraft are commonly used in control programs for wolves, coyotes, bobcats, and foxes. Hunting is most effective with snow coverFederal law requires each state where aerial hunting is allowed to issue aerial hunting permits. Some states also require low-level flying waivers.
43Traps Cage traps can be used to capture predators of all sizes Foothold traps are more effective and available in various sizesMost 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
44Calling and ShootingCan 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.
45Hunting 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 usedSight houndsGreyhoundMost effective in open terrainTrail houndsRedbone, Walker, Bluetick, Black & TanHunt by scent in packs
46SnaresConstructed of wire or cable looped through a locking device that allows the snare to tightenTwo 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 passagewaySpring activated foot snares are used to capture large predators
47SUMMARYWildlife 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.