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Sustained Evaluation Of The Effectiveness Of Detector Dogs For Locating Brown Tree Snakes In Cargo Outbound From Guam, Richard M. Engeman, Daniel S. Vice, Darryl York, Kenneth S. Gruver

United States Department of Agriculture Wildlife Services: Staff Publications

The accidental introduction of the brown tree snake (Boiga irregularis) to Guam has resulted in the extirpation of most of the island's native terrestrial vertebrates, has created a health hazard to infants and children, and has resulted in economic losses. The high brown tree snake population densities on Guam, the species' adaptations for successful dispersal, and Guam's position as a focal point for commercial and military cargo shipments have created a high level of concern that brown tree snakes could spread from Guam to colonize other vulnerable locations. Cargo inspections using teams of handlers and their detector dogs …

Estimating Deer Damage Losses In Cabbage, Richard M. Engeman, Brian K. Maedke, Scott F. Beckerman

United States Department of Agriculture Wildlife Services: Staff Publications

A standardized procedure for estimating deer damage in cabbage is used to settle claims for compensation of losses in the state of Wisconsin. By completely enumerating all damaged heads of cabbage in a field. We validated the standard procedure for accuracy. The general paradigm used for assessing losses requires a subjective examination of the field to define strata with and without damage, obtaining representative samples of undamaged heads in each strata with 3 quadrants. then converting the difference in density of undamaged heads between strata into an estimate of damage for the entire field. Weighing a sample of undamaged heads …

Caffeine As A Repellent For Slugs And Snails, Robert G. Hollingsworth, John W. Armstrong, Earl Campbell

United States Department of Agriculture Wildlife Services: Staff Publications

Most commercial products for snail and slug control contain either metaldehyde or methiocarb as the active ingredient, the residues of which are not permitted in food crops in the United States. We have discovered that solutions of caffeine are effective in killing or repelling slugs and snails when applied to foliage or the growing medium of plants. Because caffeine is a natural product and is classified by the United States Food and Drug Administration as a GRAS (‘generally recognized as safe’) compound, it has potential as an environmentally acceptable alternative toxicant for the control of slugs and snails on food …

A Comparison Of Four Rodent Control Methods In Philippine Experimental Rice Fields, Md. Sayed Ahmed, Lynwood A. Fiedler

United States Department of Agriculture Wildlife Services: Staff Publications

Four rodent control techniques-sustained baiting (SB) with coumachlor. pulsed baiting (PB) with brodifacoum. a lethal electrified barrier (LEB), and a nonlethal electrified barrier (NLEB)-were evaluated on the experimental farm of the International Rice Research Institute (IRRI) in the Philippines. A fifth treatment (no experimental rodent control) was established for reference. Mean tiller damage and rodent activity, respectively. near harvest were 1.00%1 and 1.5% in the LEB plots, 1.6% and 18.0% in the SB plots, 2.1% and 16.0 % in the PB plots, and 4.1% and 32.5% in the NLEB plots. Highest mean tiller damage (9.3%) and rodent activity (56.0%) occurred …

Aerosolized Essential Oils And Individual Natural Product Compounds As Brown Treesnake Repellents , Larry Clark, John Shivik

United States Department of Agriculture Wildlife Services: Staff Publications

Chemical irritants useful as repellents for brown treesnakes (Boiga irregularis) were identified. Exposure to various compounds produced a range of intensities for locomotory behavior in snakes. Essential oils comprised of 10 g liter ^-1 solutions of cedarwood, cinnamon, sage, juniper berry, lavender and rosemary each were potent snake irritants. Brown treesnakes exposed to a 2-s burst of aerosol of these oils exhibited prolonged, violent undirected locomotory behavior. In contrast, exposure to a 10 g liter^-1 concentration of ginger oil aerosol caused snakes to locomote, but in a deliberate, directed manner. We also tested specific compounds, all derivative …

Reproduction In Captive Wild-Caught Coyotes (Canis Latrans), Jeffrey S. Green, Frederick F. Knowlton, William C. Pitt

United States Department of Agriculture Wildlife Services: Staff Publications

We assessed reproductive patterns of coyotes (Canis latrans) from a 12-year data set involving 24 pairs of captive animals acquired from Latah County, Idaho. None of the females had placental scars (fetal implantation sites) at 1 year of age, but over 80% had placental scars by 2 years of age. The fraction with placental scars remained at 80–90% through age 9 years and then declined to ,40% by age 12 years. Similarly, mean number of placental scars per female rose rapidly through 2–3 years of age, remained stable until age 8 years, and then progressively declined to a …

Uncertainty Of Exploitation Estimates Made From Tag Returns, L.E. Miranda, R.E. Brock, Brian S. Dorr

United States Department of Agriculture Wildlife Services: Staff Publications

Over 6,000 crappies Pomoxis spp. were tagged in five water bodies to estimate exploitation rates by anglers. Exploitation rates were computed as the percentage of tags returned after adjustment for three sources of uncertainty: post-release mortality due to the tagging process, tag loss, and the reporting rate of tagged fish. Confidence intervals around exploitation rates were estimated by re-sampling from the probability distributions of tagging mortality, tag loss, and reporting rate. Estimates of exploitation rates ranged from 17% to 54% among the five study systems. Uncertainty around estimates of tagging mortality, tag loss, and reporting resulted in 90% confidence intervals …

Distribution, Abundance And Habitat Use Of American White Pelicans In The Delta Region Of Mississippi And Along The Western Gulf Of Mexico Coast, D. Tommy King, Thomas C. Michot

United States Department of Agriculture Wildlife Services: Staff Publications

Aerial surveys of American White Pelicans (Pelecanus erythrorhynchos) were conducted over coastal Louisiana and the delta region of Mississippi on 1-2 days during December, February, and April each year from 1997 to 1999. Additional surveys were conducted in coastal Texas and Mexico during January 1998 and 1999. The numbers, location, and habitat of all pelicans observed were recorded. The coastal zone of Louisiana consistently had higher numbers of pelicans (18,000 to 35,000 birds) than other areas surveyed (3,000 to 8,000 birds), indicating that Louisiana may be the most important wintering area for American White Pelicans east of the …

Effect Of Roost Harassment On Cormorant Movements And Roosting In The Delta Region Of Mississippi, Mark E. Tobin, D. Tommy King, Brian S. Dorr, Scott J. Werner, David S. Reinhold

United States Department of Agriculture Wildlife Services: Staff Publications

Double-crested Cormorant (Phalacrocorax auritus) predation on Channel Catfish (Ictalurus punctatus) at commercial farms has been estimated to cost the Mississippi aquaculture industry approximately $5 million annually to replace consumed fingerlings. In 1997, catfish producers assumed responsibility for the dispersal of cormorants in night roosts in the eastern (interior) delta region of Mississippi, where catfish farms are concentrated. We documented movements of 50 cormorants marked with radio transmitters in the delta region from January through March 1997. We obtained 161 post-capture day locations and 176 post-capture night roost locations. Cormorants that were harassed at their night roost …

Assessment Of Hazards To Non-Native Mongooses (Herpestes Auropunctatus) And Feral Cats (Felis Catus) From The Broadcast Application Of Rodenticide Bait In Native Hawaiian Forests, Peter A. Dunlevy, Earl W. Campbell Iii

United States Department of Agriculture Wildlife Services: Staff Publications

Primary non-target hazard assessment can be separated into two basic components: bait acceptance and toxicity. This bait acceptance study investigates the potential primary non-target hazard (direct consumption of bait pellets) that the broadcast application of rodenticide bait may pose to non-native feral cats and mongooses The study was conducted in 4 different forest habitats in Hawaii using 2 different commercial formulations of placebo bait pellets. We documented vertebrates that came to placebo bait pellets at bait monitoring stations to assess bait acceptance. Bait pellets were monitored at each site using 40 infrared (IR) monitors/data loggers and weatherproof automatic cameras. During …

Oral Rabies Vaccination: A National Perspective On Program Development And Implementation, Dennis Slate, Richard B. Chipman, Charles E. Rupprecht, Thomas J. Deliberto

United States Department of Agriculture Wildlife Services: Staff Publications

Persistence of unique rabies virus variants in a diverse array of terrestrial carnivores and insectivorous bats makes rabies control in the US. a complex task The public health system in the U.S. is effective in keeping human deaths near zero each year in the face of enzootic wildlife rabies, but the annual cost of coexistence with the disease is high, exceeding $300 million. In addition, each year tens of thousands of people are impacted by anxiety, fear, and trauma associated with potential or actual rabies exposure to themselves and their domestic animals. Exclusion, proper storage and disposal of garbage, and …

Have Population Increases Of Large Birds Outpaced Airworthiness Standards For Civil Aircraft?, Richard A. Dolbeer, Paul Eschenfelder

United States Department of Agriculture Wildlife Services: Staff Publications

Bird-aircraft collisions (bird strikes) are an increasing safety and economic concern to the USA civil aviation industry, costing over $400 million each year. One approach to reducing risks associated with strikes is to require commercial aircraft components to meet certain standards of safe performance in the event of a bird strike. The Federal Aviation Administration has developed airworthiness standards for airframes, windshields and engines using a single 4-lb (1.82-kg) bird mass as the maximum that must be tested (with the exception of a single 8-lb bird for the empennage, 6-lb bird for certain mid-sized engines that may be developed in …

An Extraordinary Raccoon, Procyon Lotor; Density At An Urban Park, Henry T. Smith, Richard M. Engeman

United States Department of Agriculture Wildlife Services: Staff Publications

We report on a high density Raccoon (Procyon lotor) population at a 70.9 ha urban park in Fort Lauderdale, Florida, where in a five-day period 160 raccoons/km², and is one of the densest Raccoon populations reported. We discuss the ramifications of high density urban Raccoon populations relative to wildlife disease contagions and endangered species protection.

Avian Repellents, Michael L. Avery

United States Department of Agriculture Wildlife Services: Staff Publications

The use of repellents to protect crops from birds has a long history. Early European settlers in eastern North America observed that native Americans used an extract of Veratrum spp. to protect corn seeds from avian depredators: ‘‘Then when the starlings, crows, or other birds, pick up or pluck out the grains of corn, their heads grow delirious, and they fall, which so frightens the rest that they never venture on the field again. When those which have tasted the grains recover, they leave the field, and are no more tempted to visit it again’’ (1).

Repellents move birds from …

Vegetation Management Approaches For Reducing Wildlife-Aircraft Collisions, Scott C. Barras, Thomas W. Seamans

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife-aircraft collisions (wildlife strikes) pose safety risks to aircraft and cost civil aviation over $390 million annually in the USA. We reviewed the results of prior studies to summarize the vegetation management techniques that have proven effective for wildlife strike reduction or have shown potential for achieving the same goal. Habitat components that may affect wildlife use of airports include food, cover, water, and loafing areas. Improperly managed natural and ornamental vegetation on airports can be important attractants for wildlife that pose strike hazards. However, effective vegetation management can reduce these hazards. Maintaining tall herbaceous vegetation may reduce the availability …

Behavioral And Ecological Considerations For Managing Bird Damage To Cultivated Fruit, Michael L. Avery

United States Department of Agriculture Wildlife Services: Staff Publications

Many bird species eat fruits and, likewise, many plant species are dependent on birds for the dispersal of seeds. Through cultivation and selective breeding, attributes of wild fruit have been changed to make fruit more palatable to humans. For example, cultivated species bear fruits that are often thinner-skinned. are more succulent, have fewer seeds and are easier to pick than non-cultivated species. These same changes, however, have also increased the attractiveness of fruit to avian consumers. Ecological relationships that have developed across evolutionary time between wild plants and frugivores become emphasized by the introduction of cultivated fruits that have been …

Habitat Management Approaches For Reducing Wildlife Use Of Airfields, Scott C. Barras, Thomas W. Seamans

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife-aircraft collisions (wildlife strikes) pose safety risks to aircraft and cost civil aviation over $390 million annually in the USA We reviewed published studies to summarize findings on habitat management techniques that have shown potential for wildlife strike reduction. Habitat components that may attract wildlife to airports include food, cover, water, and loafing areas. Although maintaining tall herbaceous vegetation on airfields may reduce the attractiveness of loafing and feeding sites for some species of birds such as gulls, this strategy may also increase cover and food resources for other hazardous species. Thus, optimum vegetation height management strategies require further research …

Understanding Avian Vision: The Key To Using Light In Bird Management, Bradley F. Blackwell

United States Department of Agriculture Wildlife Services: Staff Publications

Vision is a primary and highly developed sensory pathway in buds. Light, both diffuse and wavelength-specific (e.g., as produced by lasers) has recently been demonstrated as a potential means of effecting changes in timing and consistency of flock response to an approaching vehicle (simulating an aircraft) and as an avian dispersal method. However, in experiments to date, the effectiveness of light in eliciting an avoidance or dispersal response in birds has varied by species and context. To effectively use light in managing avian conflicts with humans, a better understanding of the complexities of avian retinal physiology relative to phototaxic responses …

Non-Lethal Radio Activated Guard For Deterring Wolf Depredation In Idaho: Summary And Call For Research, Stewart W. Breck, Rick Williamson, Carter Niemeyer, John A. Shivik

United States Department of Agriculture Wildlife Services: Staff Publications

With the reestablishment of wolves in the western United States, managing adverse interactions between wolves and livestock is re-emerging as an issue for resource managers. Lethal control of wolves is often difficult to implement due to the constraints of the Endangered Species Act, predator population goals, and public disfavor for lethal control. In response to the need to manage wolf predation in a non-lethal manner, we developed and tested a behavior contingent system for disrupting predation events. The Avian Systems Model 9000 Frightening System, also called a Radio Activated Guard (RAG), is activated by signals from nearby wolf radio collars. …

Population Increases Of Large Bird Species In Relation To Impact Standards For Aircraft Engines And Airframes, Richard A. Dolbeer

United States Department of Agriculture Wildlife Services: Staff Publications

Bird-aircraft collisions (bird strikes) are an increasing safety and economic concern to the USA civil aviation industry, costing over $400 million each year. One approach to reducing risks associated with strikes is to require commercial aircraft components to meet certain standards of safe performance in the event of a bird strike. The Federal Aviation Administration has developed airworthiness standards for airframes, windshields and engines using a single 4-lb (1.82-kg) bird mass as the maximum that must be tested (with the exception of a single 8-lb bird for the empennage, 6-lb bird for certain mid-sized engines that may be developed in …

Lasers As Non-Lethal Avian Repellents: Potential Applications In The Airport Environment, Bradley F. Blackwell, Glen E. Bernhardt, Jonathon D. Cepek, Richard A. Dolbeer

United States Department of Agriculture Wildlife Services: Staff Publications

Research conducted by the U.S. Department of Agriculture’s (USDA) National Wildlife Research Center (NWRC) indicates that low- to moderate-power, long-wavelength lasers (630- 650 nm) provide an effective means of dispersing some “problem” bird species under low-light conditions, while presenting no threat to the animal or the environment. The NWRC researchers tested the hypothesis that birds would avoid the beam or beam spot produced by a laser in low ambient light. In the format of controlled, replicated, 2-choice experiments with captive birds, Canada geese (Branta canadensis; 6 groups; 4 birds/group) exhibited extreme avoidance of laser beams over 80-minute periods, …

A Comparison Of Potential Labor-Saving Sampling Methods For Assessing Large Mammal Damage In Corn, Richard . M. Engeman, Ray T. Sterner

United States Department of Agriculture Wildlife Services: Staff Publications

Accurate estimation of crop damage by wildlife often requires labor-intensive sampling procedures. Variable area transect (VAT) sampling has been identified as a potential labor-saving alternative to quadrat sampling. We fully enumerated all damaged corn plants in a field to assess accuracy of sampling by small quadrats 5m long by one or two row-widths, and by VAT sampling with searches from random starting points to the 3rd, 4th, 5th, and 6th damaged plant. Two widths for strip transects also were considered for VAT sampling: one and two crop rows. Two analytical formulae were considered for the VAT data. Thus, 18 estimates …

An Economic Analysis Of Predator Removal Approaches For Protecting Marine Turtle Nests At Hobe Sound National Wildlife Refuge, Richard M. Engeman, Stephanie A. Shwiff, Bernice Constantin, Margo Stahl, Henry T. Smith

United States Department of Agriculture Wildlife Services: Staff Publications

Hobe Sound National Wildlife Refuge (HSNWR) on Florida’s east coast provides undisturbed nesting habitat for three species of threatened or endangered marine turtles. Predation by raccoons and armadillos poses the greatest risk to turtle nests, and predator control has been identified as the most important management tool for enhancing nesting productivity. Recently, estimates of the number of nests that would have been lost in the 2000 nesting and incubation season were made using the results from four control approaches. These approaches were, in order of descending complexity: (1) refuge control enhanced by a one person-month contract with federal control specialists, …

Monetary Valuation Methods For Economic Analysis Of The Benefit-Costs Of Protecting Rare Wildlife Species From Predators, Richard M. Engeman, Stephanie A. Shwiff, Henry T. Smith, Bernice Constantin

United States Department of Agriculture Wildlife Services: Staff Publications

Many threatened and endangered species are negatively impacted by predation. Management of the predators that are geographically and temporally in position to threaten species of concern can greatly aid in their conservation. However, decisions on management strategies are based within economic constraints, while the success of management actions is measured by wildlife resource improvement. Here, we review methods for applying monetary valuations for threatened and endangered species so that economic analyses of management actions can be used to help guide and evaluate management decisions. A variety of applied examples are provided to demonstrate the principles.

A New Flavor-Coated Sachet Bait For Delivering Oral Rabies Vaccine To Raccoons And Coyotes, Samuel B. Linhart, John C. Wlodkowski, Darrell M. Kavanaugh, Laurie Motes-Kreimeyer, Andrew J. Montoney, Richard B. Chipman, Dennis Slate, Laura L. Bigler, Malcomb G. Fearneyhough

United States Department of Agriculture Wildlife Services: Staff Publications

Research was conducted during 1996–2000 to develop baits for delivering an oral rabies vaccine to raccoons (Procyon lotor) and coyotes (Canis latrans). A bait was sought that: (1) was attractive to the target species, (2) could be distributed by aircraft, (3) was as effective (or more so) than the currently used fish meal polymer bait, and (4) could be produced in large numbers by automated procedures and could be purchased by user groups at substantially lower cost.

Ten field trials were conducted to document raccoons’ bait flavor preferences, evaluate a new vaccine sachet bait coated with …

A Baiting System For Delivery Of An Oral Plague Vaccine To Black-Tailed Prairie Dogs, Terry E. Creekmore, Tonie E. Rocke, Jerry Hurley

United States Department of Agriculture Wildlife Services: Staff Publications

Laboratory and field studies were conducted between July and October 1999 to identify bait preference, biomarker efficacy, and bait acceptance rates for delivering an oral plague vaccine to black-tailed prairie dogs (Cynomys ludovicianus). Twenty juvenile captive prairie dogs were offered alfalfa baits containing either alfalfa, alfalfa and 5% molasses, or alfalfa, 5% molasses and 4% salt. Based on the results of these trials we selected a bait containing alfalfa, 7% molasses, and 1% salt for field trials to determine bait acceptance rates by free-ranging animals. The biomarkers DuPont Blue dye, iophenoxic acid, and tetracycline hydrochloride were orally administered …

Safety Of Brucella Abortus Strain Rb51 Vaccine In Non-Target Ungulates And Coyotes, Terry J. Kreeger, Thomas J. Deliberto, Steven C. Olsen, William H. Edwards, Walter E. Cook

United States Department of Agriculture Wildlife Services: Staff Publications

Brucellosis is endemic in free-ranging elk (Cervus elaphus) and bison (Bison bison) in the Greater Yellowstone Area (GYA; USA). It is possible that an oral brucellosis vaccine could be developed and disseminated in the GYA to reduce disease transmission. Should this occur, non-target species other than elk and bison may come in contact with the vaccine resulting in morbidity or mortality. To assess biosafety, bighorn sheep (Ovis canadensis; n=10), pronghorn (Antilocapra americana; n=9), mule deer (Odocoileus hemionus; n=11), moose (Alces alces shirasi; n=10), and …

Quantification Of Plasma And Egg 4,4′ Dinitrocarbanilide (Dnc) Residues For The Efficient Development Of A Nicarbazin-Based Contraceptive For Pest Waterfowl, John J. Johnston, Walter M. Britton, Alexander Macdonald, Thomas M. Primus, Margaret J. Goodall, Christi A. Yoder, Lowell A. Miller, Kathleen A. Fagerstone

United States Department of Agriculture Wildlife Services: Staff Publications

Urbanization and associated landscaping has increased the abundance of year-round habitat for waterfowl, resulting in vegetation damage, loss of recreational activities, air transportation mishaps and health hazards. As part of a research program to develop socially acceptable techniques for management of pest bird populations, we are evaluating nicarbazin as a contraceptive in pest and surrogate avian species. As reproductive studies with Canada Geese (Branta canadensis) are tedious due to the difficulty of conducting controlled field studies and/or breeding geese in captivity, we evaluated the effects of oral nicarbazin administration on the production and hatchability of chicken studies are …

Non-Target Impacts Of Strychnine Baiting To Reduce Pocket Gopher Populations On Forest Lands In The United States, Dale L. Nolte, Kimberly Wagner

United States Department of Agriculture Wildlife Services: Staff Publications

Reforestation efforts are often severely hindered on sites that contain high populations of pocket gophers (Thmmysspp). Strychnine baiting is a technique used to suppress pocket gopher populations until seedlings are established. Strychnine bait is applied below ground in pocket gopher burrows, however, primary and secondary hazards remain a concern. A study to assess primary hazards indicated that some individual rodents died post strychnine baiting but there was not a long-term negative impact on non-target rodent populations. Possible secondary hazards reflect the potential for predators OT scavengers to encounter poisoned pocket gophers. Concerns that pocket gophers may surface before …

Differential Responses Of Coyotes To Novel Stimuli In Familiar And Unfamiliar Settings, Charles E. Harris, Frederick F. Knowlton

United States Department of Agriculture Wildlife Services: Staff Publications

We studied behavioral responses of captive and wild coyotes (Canis latrans) toward novel objects and artificial scent stations to determine how they might respond to novel stimuli used in coyote management and research. When captive coyotes encountered novel stimuli in unfamiliar surroundings they showed little avoidance, while the same stimuli caused avoidance and neophobic reactions among coyotes when encountered in familiar surroundings. In the field phase of the study, radio-collared coyotes in southern Texas were intensively monitored in order to relate space-use patterns to the locations where these coyotes were exposed to artificial scent stations. Coyotes were more …