Life Sciences Commons^™

Immunocontraception In Eastern Gray Squirrels (Sciurus Carolinensis): Morphologic Changes In Reproductive Organs, Murali Pai, R. Bruner, Donald H. Schlafer, Greg K. Yarrow, C. A. Yoder, Lowell A. Miller

United States Department of Agriculture Wildlife Services: Staff Publications

Eastern gray squirrels (EGS) (Sciurus carolinensis) damage trees through bark stripping or gnawing due to territorial marking or agonistic gnawing behavior in concert with higher densities. This study was conducted to determine the effects of a contraceptive vaccine on EGS and its reproductive organ histology. Free ranging urban EGS were vaccinated with the immunocontraceptive GonaCon™. All EGS were ≥6 mo. of age as determined by a combination of pelage characteristics and body weights. The vaccine was administered by injection at a dosage rate of 0.4 ml containing 400 μg of GnRH-mollusk protein conjugate i.m. in the thigh to …

A Field Evaluation Of A Trap For Invasive American Bullfrogs, Nathan P. Snow, Gary W. Witmer

United States Department of Agriculture Wildlife Services: Staff Publications

Native to the eastern United States, American bullfrogs (Rana catesbeiana [Lithobates catesbeianus]) have been introduced in many countries throughout the world. There have been relatively few effective and efficient control methods developed to manage bullfrogs. Particularly in the Hawaiian Islands, Pacific coast of North America, and Japan, finding effective methods for controlling invasive bullfrogs is needed with special emphasis on low impacts for sensitive native species. We conducted a field study to examine the efficacy of a newly designed live trap for capturing invasive bullfrogs. We found that our trap was successful at capturing bullfrogs because we …

Evaluation Of Fences For Containing Feral Swine Under Simulated Depopulation Conditions, Michael J. Lavelle, Kurt C. Vercauteren, Hefley, Gregory E. Phillips, Scott Hygnstrom, David B. Long, Justin W. Fischer, Seth R. Swafford, Tyler A. Campbell

United States Department of Agriculture Wildlife Services: Staff Publications

Populations of feral swine (Sus scrofa) are estimated to include >2 million animals in the state of Texas, USA, alone. Feral swine damage to property, crops, and livestock exceeds $50 million annually. These figures do not include the increased risks and costs associated with the potential for feral swine to spread disease to domestic livestock. Thus, effective bio-security measures will be needed to quickly isolate affected feral swine populations during disease outbreaks. We evaluated enclosures built of 0.86-m-tall traditional hog panels for containing feral swine during 35 trials, each involving 6 recently caught animals exposed to increasing levels …

Excluding Nontarget Species From Brown Tree Snake, Boiga Irregularis (Reptilia: Colubridae), Bait Stations: Experimental Tests Of Station Design And Placement, Tom Mathies, Russell Scarpino, Brenna A. Levine, Craig S. Clark, Julie A. Savidge

United States Department of Agriculture Wildlife Services: Staff Publications

Bait stations with toxic baits are an emerging technology for eradication of the invasive brown tree snake (Boiga irregularis) on Guam, yet potential interferences by nontarget species are largely unknown. We tested the efficacies of three bait station designs together with three commonly used station support structures to exclude nonnative rats (roof rat, Rattus rattus; Norway rat, Rattus norvegicus; Polynesian rat, Rattus exulans) and native coconut crabs (Birgus latro). When directly presented, all species readily consumed the dead neonatal mouse baits (nontoxic) including those replicating decomposing baits in the field. When bait stations …

The Need To Quantify Ecosystem Services Provided By Birds, Daniel G. Wenny, Travis L. Devault, Matthew D. Johnson, Dave Kelly, Cagan H. Sekercioglu, Diana F. Tomback, Christopher J. Whelan

United States Department of Agriculture Wildlife Services: Staff Publications

What are the birds worth--what is their actual dollar value to human society? To most of us in the ornithological community, birds are invaluable. But in these times we need more specific rationales to convince policy makers and business leaders to include bird conservation in land-use and development decisions. Over the past two decades, awareness of our dependence on a variety of ecosystem services (natural ecological processes that benefit human society) and of their importance and prevalence has progressed toward the goal of making conservation a mainstream value. Building strategies for the protection of ecosystem services into conservation and land-use …

Active Use Of Coyotes (Canis Latrans) To Detect Bovine Tuberculosis In Northeastern Michigan, Usa, Are R. Berentsen, Michael R. Dunbar, Shylo R. Johnson, S. Robbe-Austerman, L. Martinez, R. L. Jones

United States Department of Agriculture Wildlife Services: Staff Publications

Bovine tuberculosis (bTB) is endemic in white-tailed deer (Odocoileus virginianus) in northeastern Michigan, USA, and research suggests transmission to cattle. Prevalence of the disease in deer is estimated at 1.8%, but as prevalence decreases the difficulty of detection increases. Research suggests coyotes (Canis latrans) have a higher prevalence of bTB in Michigan than deer and sampling coyotes may be a more efficient surveillance tool to detect presence or spread of the disease. Coyotes possess suitable ecological characteristics to serve as a sentinel species, assuming transmission between coyotes is not significant. The question of whether free-ranging coyotes shed Mycobacterium bovis, the …

The Carrot Or The Stick? Evaluation Of Education And Enforcement As Management Tools For Human-Wildlife Conflicts., Sharon Baruch-Mordo, Stewart W. Breck, Kenneth R. Wilson, John Broderick

United States Department of Agriculture Wildlife Services: Staff Publications

Evidence-based decision-making is critical for implementing conservation actions, especially for human-wildlife conflicts, which have been increasing worldwide. Conservation practitioners recognize that long-term solutions should include altering human behaviors, and public education and enforcement of wildlife-related laws are two management actions frequently implemented, but with little empirical evidence evaluating their success. We used a system where human-black bear conflicts were common, to experimentally test the efficacy of education and enforcement in altering human behavior to better secure attractants (garbage) from bears. We conducted 3 experiments in Aspen CO, USA to evaluate: 1) on-site education in communal dwellings and construction sites, 2) …

Vulture Flight Behavior And Implications For Aircraft Safety, Michael L. Avery, John S. Humphrey, Trey S. Daughtery, Justin W. Fischer, Michael P. Milleson, Eric A. Tillman, William E. Bruce, W. David Walter

United States Department of Agriculture Wildlife Services: Staff Publications

Growing vulture populations represent increasing hazards to civil and military aircraft. To assess vulture flight behavior and activity patterns at the Marine Corps Air Station in Beaufort, South Carolina, we equipped 11 black vultures (Coragyps atratus) and 11 turkey vultures (Cathartes aura) with solarpowered Global Positioning System (GPS) satellite transmitters during a 2-year study (1 Oct 2006–30 Sep 2008). Turkey vultures had larger seasonal home ranges than did black vultures, and 2 turkey vultures made round-trips to Florida. Black vultures consistently spent less time in flight (8.4%) than did turkey vultures (18.9%), and black vultures flew at higher altitudes than …

Efficacy Of European Starling Control To Reduce Salmonella Enterica Contamination In A Concentrated Animal Feeding Operation In The Texas Panhandle, James C. Carlson, Richard M. Engeman, Doreene R. Hyatt, Rickey L. Gilliland, Thomas J. Deliberto, Larry Clark, Michael J. Bodenchuck, George M. Linz

United States Department of Agriculture Wildlife Services: Staff Publications

Background: European starlings (Sturnus vulgaris) are an invasive bird species known to cause damage to plant and animal agriculture. New evidence suggests starlings may also contribute to the maintenance and spread of diseases within livestock facilities. Identifying and mitigating the risk pathways that contribute to disease in livestock is necessary to reduce production losses and contamination of human food products. To better understand the impact starlings have on disease transmission to cattle we assessed the efficacy of starling control as a tool to reduce Salmonella enterica within a concentrated animal feeding operation. We matched a large facility, slated for operational …

Nilgai Antelope In Northern Mexico As A Possible Carrier For Cattle Fever Ticks And Babesia Bovis And Babesia Bigemina., E M. Cardenas-Canales, J. Alfonso Ortega-Santos, Tyler A. Campbell, Zeferino Garcia-Vaquez, Antonio Cantu-Covarrubias, Julio V. Figueroa-Millian, Randy W. Deyoung, David G. Hewitt, Fred C. Bryant

United States Department of Agriculture Wildlife Services: Staff Publications

Of 20 blood samples from nilgais from Me´ xico, five were polymerase chain reaction-positive for Babesia bigemina and one for Babesia bovis. Positive samples had the expected 170 (B. bigemina) and 291 (B. bovis) base pairs and were identical to Gen-Bank B. bigemina accession S45366 and B. bovis M38218.

Diseases And Parasites, Kurt C. Vercauteren, Tyler A. Campbell

United States Department of Agriculture Wildlife Services: Staff Publications

No abstract provided.

Efficacy Of The Boar-Operated-System To Deliver Baits To Feral Swine., Tyler A. Campbell, David B. Long, Giovanna Massei

United States Department of Agriculture Wildlife Services: Staff Publications

Feral swine (Sus scrofa) pose a significant disease threat to livestock and humans. Emerging technologies to reduce feral swine disease transmission risks include fertility control, vaccination, and toxicants. However, for these technologies to be appropriate for field application, a feral swine-specific oral delivery system is needed. We used two field trials to generate information related to appropriate field application of the Boar-Operated-System (BOSTM), an oral delivery system designed to provide bait access only to feral swine. Our objectives were to determine whether pre-baiting BOSTM units increased bait removal and to evaluate the proportion of feral swine and non-target animals that …

Interface Between Black-Footed Ferret Research And Operational Conservation., Dean E. Biggins, Travis M. Livieri, Stewart W. Breck

United States Department of Agriculture Wildlife Services: Staff Publications

Questions and problems that emerged during operational conservation of black-footed ferrets (Mustela nigripes)have been addressed by a wide variety of studies. Early results from such studies often were communicated orally during meetings of recovery groups and in written form using memoranda, unpublished reports, and theses. Typically, implementation of results preceded their publication in widely distributed journals. Many of these studies eventually were published in journals, and we briefly summarize the contents of 8 volumes and special features of journals that have been dedicated to the biology of ferrets and issues in ferret recovery. This year marks the 30th anniversary of …

White-Tailed Deer Incidents With U.S. Civil Aircraft, Kirsten M. Biondi, Jerrold L. Belant, James A. Martin, Travis L. Devault, Guiming Wang

United States Department of Agriculture Wildlife Services: Staff Publications

Aircraft incidents with ungulates cause substantial economic losses and pose risks to human safety. We analyzed 879 white-tailed deer (Odocoileus virginianus) incidents with United States civil aircraft from 1990 to 2009 reported in the Federal Aviation Administration National Wildlife Strike Database. During that time, deer incidents followed a quadratic response curve, peaking in 1994 and declining thereafter. There appeared to be some seasonal patterning in incident frequency, with deer incidents increasing overall from January to November, and peaking in October and November (30.7%). Most incidents (64.8%) occurred at night, but incident rates were greatest (P 0.001) at dusk. Landing-roll represented …

Acetaminophen And Zinc Phosphide For Lethal Management Of Invasive Lizards Ctenosaura Similis , Michael L. Avery, John D. Eisemann, Kandy L. Keacher, Peter J. Savarie

United States Department of Agriculture Wildlife Services: Staff Publications

Reducing populations of invasive lizards through trapping and shooting is feasible in many cases but effective integrated management relies on a variety of tools, including toxicants. In Florida, using wild-caught non-native black spiny-tailed iguanas Ctenosaura similis, we screened acetaminophen and zinc phosphide to determine their suitability for effective population management of this prolific invasive species. Of the animals that received acetaminophen, none died except at the highest test dose, 240 mg per lizard, which is not practical for field use. Zinc phosphide produced 100% mortality at dose levels as little as 25 mg per lizard, equivalent to about 0.5% in …

Hair Of The Dog: Obtaining Samples From Coyotes And Wolves Noninvasively, David E. Ausband, Julie K. Young, Barbara Fannin, Michael S. Mitchell, Jennifer L. Stenglen, Lizette P. Waits, John A. Shivik

United States Department of Agriculture Wildlife Services: Staff Publications

Canids can be difficult to detect and their populations difficult to monitor. We tested whether hair samples could be collected from coyotes (Canis latrans) in Texas, USA and gray wolves (C. lupus) in Montana, USA using lure to elicit rubbing behavior at both man-made and natural collection devices. We usedmitochondrial and nuclearDNA to determine whether collected hair samples were from coyote, wolf, or nontarget species. Both coyotes and wolves rubbed on man-made barbed surfaces but coyotes in Texas seldom rubbed on hanging barbed surfaces. Wolves in Montana showed a tendency to rub at stations where natural material collection devices (sticks …

Modeling Connectivity Of Black Bears In A Desert Sky Island Archipelago, Todd C. Atwood, Julie K. Young, Jon P. Beckmann, Stewart W. Breck, Jennifer A. Fike, Olin E. Rhodes Jr., Kirby D. Bristow

United States Department of Agriculture Wildlife Services: Staff Publications

Landscape features such as rivers, mountains, desert basins, roads, and impermeable man-made structures may influence dispersal and gene flow among populations, thereby creating spatial structure across the landscape. In the US–Mexico borderland, urbanization and construction of the border fence have the potential to increase genetic subdivision and vulnerability to isolation in large mammal populations by bisecting movement corridors that have enabled dispersal between adjacent Sky Island mountain ranges. We examined genetic variation in black bears (Ursus americanus) from three regions in central and southern Arizona, US, to assess genetic and landscape connectivity in the US–Mexico border Sky Islands. We found …

Partitioning Of Anthropogenic Watering Sites By Desert Carnivores., Todd C. Atwood, Tricia L. Fry, Bruce Leland

United States Department of Agriculture Wildlife Services: Staff Publications

We investigated the role of water features as focal attractors for gray foxes (Urocyon cinereoargenteus), coyotes (Canis latrans), and bobcats (Felis rufus) in west Texas to determine if they were foci for interspecific interaction. Mixed effects models indicated that species partitioned use of water features spatially and temporally. Linear models indicated factors influencing relative activity at water features varied by species. For coyotes and bobcats, the water availability model, containing days since last rainfall and nearest-neighbor distance to water was best supported by the data, with relative activity increasing with time between rainfall and distance between waters. For gray foxes, …

Wild Dogma Ii: The Role And Implications Of Wild Dogma For Wild Dog Management In Australia., Benjamin L. Allen, Richard M. Engeman, Lee R. Allen

United States Department of Agriculture Wildlife Services: Staff Publications

The studies of Allen (2011) and Allen et al. (2011) recently examined the methodology underpinning claims that dingoes provide net benefits to biodiversity by suppressing foxes and cats. They found most studies to have design flaws and/or observational methods that preclude valid interpretations from the data, describing most of the current literature as ‘wild dogma’. In this short supplement, we briefly highlight the roles and implications of wild dogma for wild dog management in Australia. We discuss nomenclature, and the influence that unreliable science can have on policy and practice changes related to apex predator management

Wild Dogma: An Examination Of Recent "Evidence" For Dingo Regulation Of Invasive Mesopredator Release In Australia., Benjamin L. Allen, Richard M. Engeman, Lee R. Allen

United States Department of Agriculture Wildlife Services: Staff Publications

There is growing interest in the role that apex predators play in shaping terrestrial ecosystems and maintaining trophic cascades. In line with the mesopredator release hypothesis, Australian dingoes (Canis lupus dingo and hybrids) are assumed by many to regulate the abundance of invasive mesopredators, such as red foxes Vulpes vulpes and feral cats Felis catus, thereby providing indirect benefits to various threatened vertebrates. Several recent papers have claimed to provide evidence for the biodiversity benefits of dingoes in this way. Nevertheless, in this paper we highlight several critical weaknesses in the methodological approaches used in many of these reports, including …

Rock Pigeon Use Of Livestock Facilities In Northern Colorado: Implications For Improving Farm Bio-Security., James C. Carlson, Larry Clark, Michael F. Antolin, M. D. Salman

United States Department of Agriculture Wildlife Services: Staff Publications

Rock pigeons (Columba livia) have been implicated in the spread of pathogens within commercial livestock facilities. Currently, there is no data characterizing pigeon habitat use and movement patterns within and among commercial livestock facilities. To better understand the capacity for pigeons to spread pathogens, we used radio-telemetry techniques to estimate the home-range, travel distance, activity, and habitat use of pigeons roosting on and off dairies and feedlots in western Weld County, Colorado. Our observations suggest that pigeons roosting on (resident) and off (nonresident) livestock facilities use habitat differently. Nonresident pigeons used larger home-range areas than did resident pigeons. Nonresident pigeons …

Absence Of Mycobacterium Bovis In Feral Swine (Sus Scrofa) From The Southern Texas Border Region., Tyler A. Campbell, David B. Long, Luiz R. Bazan, Bruce V. Thomsen, Suelee Robbe-Austerman, Ronald B. Davey, Liza A. Soliz, Seth Swafford, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Free-ranging wildlife, such as feral swine (Sus scrofa), harbor a variety of diseases that are transmissible to livestock and could negatively impact agricultural production. Information is needed regarding the exposure and infection rates of Mycobacterium bovis and many other diseases and parasites in feral swine occurring in the Texas border region. Our main objective was to determine exposure rates and possible infection rates of M. bovis in feral swine by opportunistically sampling animals from the Texas border region. From June to September 2010, we obtained samples from 396 feral swine and tested 98 samples for M. bovis by histopathology and …

Natal Colony Site Fidelity Of Herring Gulls At Sandusky Bay, Ohio., Bruce N. Buckingham, Benjamin Bacak

United States Department of Agriculture Wildlife Services: Staff Publications

We studied three Herring Gull (Larus argentatus) colonies in the Sandusky Bay area, Sandusky, OH, between 1981 and 2006. During this period, we banded 24,000 nestlings and received reports of 347 recovered bands. Forty-nine of these band recoveries were as adults recovered during the nesting season as far as 890 km from their natal colony. Gulls were also captured at five other colonies located in the Great Lakes. Gulls recovered outside the original 10-min block of banding accounted for 47 percent of the returns. We hypothesize that half of the recoveries of adult Herring Gulls during the nesting season occurred …

Domestic Calf Mortality And Producer Detection Rates In The Mexican Wolf Recovery Area: Implications For Livestock Management And Carnivore Compensation Schemes., Stewart W. Breck, Bryan M. Kluever, Michael Panasci, John Oakleaf, Terry Johnson, Warren B. Ballard, Larry Howery, David L. Bergman

United States Department of Agriculture Wildlife Services: Staff Publications

Conserving large carnivores throughout the world will often require that they share the landscape with livestock. Minimizing depredations and increasing tolerance by livestock producers will be critical for conservation efforts. To investigate factors influencing calf mortality and producer detection rates (i.e., number of livestock killed by predators, found by producers, and correctly classified as to cause of death), we monitored radio-tagged domestic calves at two sites in the Mexican wolf recovery area (East Eagle [EE] and Adobe Ranch [AR]). Study areas differed in grazing practices, density of predators (mountain lions, black bears, coyotes, and Mexican wolves), and amount of effort …

Testing The Terrain Hypothesis: Canada Geese See Their World Laterally And Obliquely, Esteban Fernández-Juricic, Bret A. Moore, Megan Doppler, Joseph Freeman, Bradley F. Blackwelll, Steven L. Lima, Travis L. Devault

United States Department of Agriculture Wildlife Services: Staff Publications

The distribution of ganglion cells in the retina determines the specific regions of the visual field with high visual acuity, and thus reflects the perception of a species’ visual environment. The terrain hypothesis proposes that animals living in open areas should have a horizontal visual streak across the retina with high ganglion cell density to increase visual acuity along the horizon. We tested this hypothesis in Canada geese (Branta canadensis) by assessing retinal topography, visual field configuration, and scanning behavior. We found that geese have an oblique rather than a horizontal visual streak across the retina: from a …

Characteristics Of Road-Kill Locations Of San Clemente Island Foxes, Nathan P. Snow, William F. Andelt, Nicholas P. Gould

United States Department of Agriculture Wildlife Services: Staff Publications

Mortalities from collisions with vehicles have created concern for the welfare of the San Clemente Island fox (Urocyon littoralis clementae); 1 of only 6 genetically distinct subspecies of island fox. To find possible solutions for minimizing these mortalities, we compared 9 characteristics of roads and roadsides at kill-sites and control-sites to ascertain whether certain features were associated with risk of collisions. We found that kill-sites were positively associated with the volume of traffic, and negatively associated with the distance of motorists’ visibility, which had not been previously identified for island foxes. Additionally, visual obstructions along roadsides (i.e., steep …

Increased Abundance And First Breeding Record Of The Neotropic Cormorant (Phalacrocorax Brasilianus) On The Alluvial Plain Of Mississippi, Katie C. Hanson, Travis L. Devault, Stephen J. Dinsmore

United States Department of Agriculture Wildlife Services: Staff Publications

Phalacrocorax brasilianus (Neotropic Cormorant) has been observed with increasing frequency in the alluvial plain (Delta region) of Mississippi. In the past 6 years, 22 individuals have been observed in 20 separate sightings during spring and summer. These sightings have occurred at breeding colonies of other colonial waterbirds and commercial aquaculture facilities of Ictalurus punctatus (Channel Catfish). Two sexually mature Neotropic Cormorants have been collected at a colonial waterbird breeding colony near the Mississippi River in the western Delta region among flocks of Phalacrocorax auritus (Double-crested Cormorants). Twice during the summer of 2008, confirmed nesting of Neotropic Cormorants were documented in …

Promiscuous Mating In Feral Pigs (Sus Scrofa) From Texas, Usa, Johanna Delgado-Acevedo, Angeline Zamorano, Randy W. Deyoung, Tyler A. Campbell, David G. Hewitt, David B. Long

United States Department of Agriculture Wildlife Services: Staff Publications

Context. Feral pigs represent a significant threat to agriculture and ecosystems and are disease reservoirs for pathogens affecting humans, livestock and other wildlife. Information on the behavioural ecology of feral pigs might increase the efficiency and effectiveness of management strategies.

Aims. We assessed the frequency of promiscuous mating in relation to oestrous synchrony in feral pigs from southern Texas, USA, an agroecosystem with a widespread and well established population of feral pigs. An association between multiple paternity of single litters and synchrony of oestrous may indicate alternative mating strategies, such as mateguarding.

Methods. We collected gravid sows at …

Assessment Of Abilities Of White-Tailed Deer To Jump Fences, Kurt C. Vercauteren, Timothy R. Vandeelen, Michael J. Lavelle, Wayne Hall

United States Department of Agriculture Wildlife Services: Staff Publications

There is a need for insight into fence heights required for impeding white-tailed deer (Odocoileus virginianus). We evaluated the ability of wild-caught deer to jump progressively taller fences and documented deterrence rates of 0% for fences ≤1.5 m followed by increasing deterrence rates of 14% at 1.8 m, 85% at 2.1 m, and 100% at 2.4 m. We documented 100% deterrence rates during 5 additional experiments with different deer and the test fence at 2.4 m, a common height of fences at captive deer facilities. Our results will be valuable to those managing spread of wildlife diseases, deer–vehicle …

Management Of Damage By Elk (Cervus Elaphus) In North America: A Review, W. David Walter, Michael J. Lavelle, Justin W. Fischer, Therese L. Johnson, Scott E. Hygnstrom, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Abundant populations of elk (Cervus elaphus) are cherished game in many regions of the world and also cause considerable human–wildlife conflicts through depredation on agriculture and specialty crops, lack of regeneration to native ecosystems, collisions with vehicles and transmission of disease between free-ranging and farmed hoofstock. Management of elk varies, depending on current and historical agency objectives, configuration of the landscapes elk occupy, public perception, population density and behaviour of elk. Selection of the method to manage elk often requires knowledge of timing of impacts, duration relief from elk damage is desired, cost-effectiveness of management activities, tolerance of …