Human-Wildlife Conflict with an Emphasis on Coyote Depredation Roger A. Baldwin UCCE Wildlife Specialist Department of Wildlife, Fish, & Conservation Biology University of California, Davis
Benefits of Wildlife Physical utility Monetary Recreational Scientific Ecological Existence Adapted from Conover 2002
What Are Vertebrate Pests? Nonhuman species of vertebrate animals that are currently troublesome locally, or over a wide area, to one or more persons, either by being a health hazard, a general nuisance, or by destroying food, fiber, or natural resources.
What is Human-Wildlife Conflict? The negative interaction of humans and other vertebrate animals. Such situations could result in: - health hazards
What is Human-Wildlife Conflict? The negative interaction of humans and other vertebrate animals. Such situations could result in: - health hazards - destruction of food, fiber, or natural resources.
What is Human-Wildlife Conflict? The negative interaction of humans and other vertebrate animals. Such situations could result in: - health hazards - destruction of food, fiber, or natural resources. - general nuisance incidents
History Human-wildlife conflict has always been present. Really came to the forefront in western U.S. with an increase in livestock production and agriculture.
Livestock Issues Pioneers concerned about losses of livestock to predators. Much effort was taken to reduce or eliminate predator populations.
Livestock Damage Estimates In 2010, predators resulted in loss of 220,000 head of livestock. This totaled $98.5 million in losses to ranchers. Does not account for indirect losses (e.g., weaning weights of calves 2-10% lower in presence of wolves). $188.5 million was expended for non-lethal control of predators.
Current Control Strategies Currently, we focus on an integrated approach that utilizes a number of strategies and tools to control vertebrate pests.
Current Control Strategies Currently, we focus on an integrated approach that utilizes a number of strategies and tools to control vertebrate pests.
Management Options Two-tiered system: Nonlethal options Lethal options
Management Options Two-tiered system: Nonlethal options Lethal options Nonlethal control is principle focus
Management Options Two-tiered system: Nonlethal options Lethal options Nonlethal control is principle focus Lethal options used when needed
Management Options—Nonlethal Habitat modification Certain habitats are more conducive to depredation events. Pasturing, lambing, & calving habitat Pasture in areas with less history of depredation. Shortening birthing period can overwhelm predators. Particularly avoid these areas at sensitive times. Could graze cattle in heavy coyote depredation areas.
Management Options—Nonlethal Sanitation Removing carcasses may lessen depredation pressure. Less feasible over large areas.
Management Options—Nonlethal 1. Woven wire fence
Management Options—Nonlethal 1. Woven wire fence 2. Electric fence
Management Options—Nonlethal 1. Woven wire fence 2. Electric fence 3. Combination fence
Management Options—Nonlethal 1. Woven wire fence 2. Electric fence 4. Portable electric fence 3. Combination fence
Management Options—Nonlethal Night/seasonal enclosure Predation greatest at night. Bring livestock into enclosures at night can reduce threat. Calving and lambing in such areas also reduces threat. Not as plausible over large areas.
Management Options—Nonlethal Herding Constant human presence is effective. Allows behavioral observation. Expensive. Limited qualified labor force. Disruptive harassment Running off or shooting with rubber slugs or paint balls
Management Options—Nonlethal Guard dogs Can effectively reduce livestock losses from coyotes. Require extensive training. Can be expensive. May directly predate on livestock.
Management Options—Nonlethal Guard dogs Can effectively reduce livestock losses from coyotes. Require extensive training. Can be expensive. May directly predate on livestock. Donkeys/llamas Can also reduce livestock losses. Less training/greater longevity. Less specialized care. Less concern with other coyote management options.
Management Options—Nonlethal Visual frightening approaches Lights around pens and corrals somewhat effective. Vehicles left in area somewhat effective, especially if moved. Coyotes will habituate quickly.
Management Options—Nonlethal Visual frightening approaches Lights around pens and corrals somewhat effective. Vehicles left in area somewhat effective, especially if moved. Coyotes will habituate quickly. Auditory frightening devices Radios in animal holding areas. Propane cannons and sirens. Combinations can be most effective (e.g., Electronic Guards). More effective when triggered. Can be irritant to neighbors and efficacy is not long term.
Management Options—Nonlethal Fladry Strands of flags strung just above ground. Can keep canids out for a couple of months. Turbo fladry is often more effective. Best if used as one part of management program.
Management Options—Lethal Broad-scale population reduction Goal is to minimize population density over a broad area. Can reduce depredation events if intensive enough. Must be repeated over time to keep populations from rebounding. Is expensive. Can alter population demographics. May impact nontarget species.
Management Options—Lethal Broad-scale population reduction Historical options included: bounties trapping (including leg-hold traps) shooting (including aerial gunning)
Management Options—Lethal Broad-scale population reduction Historical options included: bounties trapping (including leg-hold traps) shooting (including aerial gunning) Current options include: snaring shooting (lead bullet ban may limit) Not widely used in CA today.
Management Options—Lethal Targeted removal Goal is to remove offending individuals. alpha pairs often responsible coyotes with pups increase problems Is less expensive. Should have little impact on nontarget species. More common approach used today.
Management Options—Lethal Targeted removal Snares
Management Options—Lethal Targeted removal Snares Calling and shooting
Management Options—Lethal Targeted removal Snares Calling and shooting Livestock protection collars no longer used in CA
Management Options—Lethal Targeted removal Den site (Wildlife Services only) pup removal reduces depredations gas cartridges
Management Options—Lethal Targeted removal Den site (Wildlife Services only) pup removal reduces depredations gas cartridges Removal over sensitive area targeted for short period/small area can be preventative or reactive
Management Options—Impacts Fencing Can alter wildlife movement. Can cause range degradation. Guard dogs Can harass wildlife. Snares If used incorrectly, could result in nontarget take.
Management Options—Example Integrated approach Fladry to deter. Scary!
Management Options—Example Integrated approach Fladry to deter. Guard animals to reinforce deterrent. Maybe not…
Management Options—Example Integrated approach Fladry to deter. Guard animals to reinforce deterrent. Lethal removal when other options fail.
Summary Coyotes and other predators are a valuable part of the environment and often cause little damage. When damage occurs, nonlethal approaches are preferred. Lethal control will be needed in some situations. The integration of a variety of control methods will provide the best results and have the least impact on the natural ecosystem.
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