Veterinary Microbiology and Immunobiology Commons^™

Limitations Of Invasive Snake Control Tools In The Context Of A New Invasion On An Island With Abundant Prey, Shane R. Siers, Melia G. Nafus, Jereid E. Calaor, Rachel M. Volsteadt, Matthew S. Grassi, Megan Volsteadt, Aaron F. Collins, Patrick D. Barnhart, Logan T. Huse, Amy A. Yackel Adams, Diane L. Vice

United States Department of Agriculture Wildlife Services: Staff Publications

In October 2020, a new population of invasive brown treesnakes (Boiga irregularis) was discovered on the 33-ha Cocos Island, 2.5 km off the south coast of Guam, United States. Cocos Island is a unique conservation resource, providing refuge for many lizards and birds, including endangered species, which were extirpated from mainland Guam by invasive predators including brown treesnakes. We sought to evaluate the usefulness of toxic baiting with acetaminophen-treated carrion baits and cage trapping, common tools for the control of brown treesnakes on mainland Guam, as potential eradication tools on Cocos Island. We evaluated multiple bait types and …

Site-Specific Space Use And Resource Selection By Black Vultures (Coragyps Atratus) In The Southeastern Usa, Betsy Evans, John S. Humphrey, Eric A. Tillman, Michael L. Avery, Bryan M. Kluever

United States Department of Agriculture Wildlife Services: Staff Publications

North American populations of Black Vultures Coragyps atratus have increased and expanded their distribution in the southern and eastern USA. In conjunction with these patterns has been a rise in human–vulture conflicts. To improve our understanding of space use patterns and better inform management, we evaluated the movements of Black Vultures (n = 23) in the southeastern USA using a long-term GPS tracking database. Our specific objectives were to: (1) quantify home-range sizes in relation to season and geographical study location and (2) examine within-home-range resource selection to identify landscape and anthropogenic factors influencing roost and diurnal space use. …

Antipredator Blood-Squirting Defense In Horned Lizards (Phrynosoma): Chemical Isolation Of Plasma Component(S), Pogonomyrmex Ant Dietary Origin, And Evolution, Wade C. Sherbrooke, Bruce A. Kimball

United States Department of Agriculture Wildlife Services: Staff Publications

North American horned lizards of the genus Phrynosoma are largely myrmecophagous and squirt systemic blood from circumocular sinuses during encounters with certain mammalian predators. The predators react with distinct revulsion. Using bioassay-guided fractionation of blood plasma, we endeavored to identify the source and characteristics of the active chemical compound(s) responsible for this negative oral response. Our results of coyote bioassays and a series of novel mouse bioassay experiments were largely concordant. The active compound(s) was likely plasma-borne with a molecular weight (mw) of between 800 and 1,600. To identify the source of the active compound(s), we noted bioassay responses …

Downed Wood Removal Effects On Survival And Site Fidelity Of Woodrats In A California Oak Woodland, Timothy J. Smyser, Michael A. Hardy, Amy J. Davis, William L. Preston, William D. Tietje

United States Department of Agriculture Wildlife Services: Staff Publications

Owing to the increasing intensity and frequency of wildfires in the western United States, the removal of woody debris (downed dead wood and snags) from fire‐prone landscapes is being evaluated for wildfire mitigation. Consequently, the study of the ecological value of coarse woody debris to sustain dependent species has become of foremost importance. From 2004–2009, we used a before‐after control‐impact (BACI) study design to assess the effects of downed wood removal on a population of big‐eared woodrats (Neotoma macrotis) in an oak woodland (Quercus spp.) in coastal‐central California, USA. Using Pollock's robust design mark‐recapture analyses (with 12 …

High Thermal Quality Rookeries Facilitate High Thermoregulatory Accuracy In Pregnant Female Rattlesnakes, Haley A. Moniz, Jack Henry Buck, Hayley L. Crowell, Scott M. Goetz, Trevor D. Ruiz, Emily N. Taylor, Scott M. Bobacks

United States Department of Agriculture Wildlife Services: Staff Publications

Temperature is a primary factor influencing organismal development, and the fluctuating daily and seasonal thermal regimes of temperate climates may challenge the ability of viviparous reptiles to optimize body temperatures during gestation. Testing how viviparous reptiles navigate highly variable thermal conditions (e.g., relatively cold nights and/or highly fluctuating temperatures) is a powerful way to understand how they use microhabitats for thermoregulatory benefits. We assessed the thermal ecology of pregnant and non-pregnant female prairie rattlesnakes (Crotalus viridis) inhabiting a high-elevation, montane shrubland in northwest Colorado throughout their short summer active season, addressing the thermal consequences of microhabitat selection with …

Characterizing Feral Swine Movement Across The Contiguous United States Using Neural Networks And Genetic Data, Rachael M. Giglio, Courtney F. Bowden, Ryan K. Brook, Antoinette J. Piaggio, Timothy J. Smyser

United States Department of Agriculture Wildlife Services: Staff Publications

Globalization has led to the frequent movement of species out of their native habitat. Some of these species become highly invasive and capable of profoundly altering invaded ecosystems. Feral swine (Sus scrofa × domesticus) are recognized as being among the most destructive invasive species, with populations established on all continents except Antarctica. Within the United States (US), feral swine are responsible for extensive crop damage, the destruction of native ecosystems, and the spread of disease. Purposeful human-mediated movement of feral swine has contributed to their rapid range expansion over the past 30 years. Patterns of deliberate introduction of …

Bayesian Integrated Species Distribution Models For Hierarchical Resource Selection By A Soaring Bird, Ryo Ogawa, Guiming Wang, L. Wes Burger, Bronson Strickland, J. Brian Davis, Fred L. Cunningham

United States Department of Agriculture Wildlife Services: Staff Publications

Migratory birds exhibit seasonal geographic range (hereafter, range) dynamics during the annual cycle. Few studies have examined how migratory birds select their habitats for range occupancy at the species level and space use at the individual level simultaneously. We hypothesized that environmental variables directly related to fitness components would affect the range occupancy probabilities of migrants, whereas environment variables related to movements and flights would affect the space use intensities of migrants. We built Bayesian integrated species distribution models (ISDMs) to evaluate the effects of climate conditions, wind conditions, and landcover compositions on the seasonal range dynamics of American white …

Raccoon Density Estimation From Camera Traps For Raccoon Rabies Management, Amy J. Davis, Wesley C. Dixon, Richard B. Chipman, Amy T. Gilbert, Jacob E. Hill, James C. Beasley, Olin E. Rhodes Jr., Guha Dharmarajan

United States Department of Agriculture Wildlife Services: Staff Publications

Density estimation for unmarked animals is particularly challenging, yet density estimates are often necessary for effective wildlife management. Raccoons (Procyon lotor) are the primary terrestrial wildlife reservoir for Lyssavirus rabies within the United States. The raccoon rabies variant (RRVV) is actively managed at landscape scales using oral rabies vaccination (ORV) within the eastern United States. To effectively manage RRVV, it is important to know the density of raccoons to appropriately scale the density of ORV baits distributed on the landscape. We compared methods to estimate raccoon densities from camera‐trap data versus more intensive capture‐mark‐recapture (CMR) estimates across 2 …

What Is Known, Unknown, And Needed To Be Known About Damage Caused By Wild Pigs, Kurt C. Vercauteren, Kim M. Pepin, Seth M. Cook, Sophie Mckee, Abigail Pagels, Keely J. Kohen, Ingrid A. Messner, Michael P. Glow, Nathan P. Snow

United States Department of Agriculture Wildlife Services: Staff Publications

Damage assessments provide evidence for initiating and evaluating management programs that protect natural resources and human livelihoods against invasive species. Wild pigs (Sus scrofa) cause extensive damage in their native and non-native ranges, but the extent of current damage and efficacy of management of the damage (i.e., population control of wild pigs, exclusion fencing, etc.) remains poorly described. We conducted a systematic review of physical damage caused by wild pigs to summarize what is known and identify knowledge gaps for damage assessment. Wild pig damage assessments have been overwhelmingly qualitative (84% of studies) and measured differently across studies, …

Tracking Sero-Molecular Trends Of Swine Brucellosis In Hawai'i And The Central Pacific, Thi Hai Au La, Ian A. Mcmillan, Prashant Dahal, Andrew H. Burger, Mahdi Belcaid, Darrin M. Phelps, Samuel M. Goldstein, Vienna R. Brown, Michael H. Norris

United States Department of Agriculture Wildlife Services: Staff Publications

Introduction

Brucellosis is a zoonotic disease of mammals caused by bacterial species of the Brucella genus. The reservoir for disease is typically mammals, with species of Brucella found infecting amphibians, bats, and marine mammals. Brucella spp. can pass directly to humans through contact with infected animals or their products. Brucella spp. can cause chronic debilitating infections in mammals, including humans, and is associated with spontaneous abortions in infected animals, causing reduced fecundity. In Hawai‘i, terrestrial species that could harbor Brucella spp. include swine, cattle, horses, and axis deer among others. The numerous feral swine in Hawai‘i are known to carry …

Genetic Tracking Of A Rabid Coyote (Canis Latrans) Detected Beyond A Rabies Enzootic Area In West Virginia, Usa, Matthew W. Hopken, Crystal Gigante, Amy T. Gilbert, Richard B. Chipman, Jordana D. Kirby, Rene Edgar Condori, Samuel Mills, Chelsea Hartley, John Forbes, Lisa Dettinger, Dongxiang Xia, Yu Li, Bridgett Vonholdt

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife translocation and cross-species transmission can impede control and elimination of emerging zoonotic diseases. Tracking the geographic origin of both host and virus (i.e., translocation versus local infection) may help determine the most effective response when high-risk cases of emerging pathogens are identified in wildlife. In May 2022, a coyote (Canis latrans) infected with the raccoon (Procyon lotor) rabies virus variant (RRV) was collected in Lewis County, West Virginia, USA, an area free from RRV. We applied host population genomics and RRV phylogenetic analyses to determine the most likely geographic origin of the rabid coyote. Coyote …

Treatment With The Immunocontraceptive Vaccine, Gonacon, Induces Temporary Fertility Control In Free-Ranging Prairie Dog Populations In Colorado, Usa, Aaron B. Shiels, Jackson Runte, Emily W. Ruell, Douglas C. Eckery, Gary W. Witmer, Daniel J. Salkeld

United States Department of Agriculture Wildlife Services: Staff Publications

Context

Prairie dogs (Cynomys spp.) are rodents enjoyed by some humans; yet, they cause crop and property damage, and carry zoonotic disease. Non-lethal control of prairie dogs is of interest in urban/suburban settings. The injectable immunocontraceptive vaccine GonaCon (active ingredient is gonadotropin-releasing hormone [GnRH]) has been shown to be effective at reducing fertility in equine and deer, and is a US EPA-registered vaccine for use in these ungulate species.

Aims

To conduct a replicated field study to test efficacy of GonaCon in black-tailed prairie dogs (C. ludovicianus), and if found to be efficacious, to help facilitate …

Comparison Of Ketamine-Xylazine, Butorphanol-Azaperone-Medetomidine, And Nalbuphine-Medetomidine-Azaperone For Raccoon (Procyon Lotor) Immobilization, Shylo R. Johnson, Christine K. Ellis, Chad Wickham, Molly R. Selleck, Amy T. Gilbert

United States Department of Agriculture Wildlife Services: Staff Publications

Raccoons (Procyon lotor) are frequently handled using chemical immobilization in North America for management and research. In a controlled environment, we compared three drug combinations: ketamine-xylazine (KX), butorphanol-azaperone-medetomidine (BAM), and nalbuphinemedetomidine- azaperone (NalMed-A) for raccoon immobilization. In crossover comparisons, raccoons received a mean of the following: 8.66 mg/kg ketamine and 1.74 mg/kg xylazine (0.104 mL/kg KX); 0.464 mg/kg butorphanol, 0.155 mg/kg azaperone, and 0.185 mg/kg medetomidine (0.017 mL/kg BAM); and 0.800 mg/kg nalbuphine, 0.200 mg/kg azaperone, and 0.200 mg/kg medetomidine (0.020 mL/kg NalMed-A). Induction time was shortest with KX (mean6SE, 10.060.7 min) and longest with NalMed-A (13.061.3 min). …

Using Prescribed Fire And Biosolids Applications As Grassland Management Tools: Do Wildlife Respond?, Brian E. Washburn, Michael J. Begier

United States Department of Agriculture Wildlife Services: Staff Publications

Prescribed burning is a management tool commonly used in forested ecosystems in the southeastern United States, but the influence of this method on grassland vegetation and wildlife in this geographic region is unknown. During 2009–2015, we conducted a study to determine if the application of prescribed burning and/or long-term biosolid applications alter plant communities and/or wildlife use of grassland areas at Marine Corps Air Station Cherry Point, Havelock, North Carolina. We monitored vegetation growth, measured plant community composition, and documented wildlife activity in four study plots for 3 years after the implementation of annual winter prescribed burns. Prescribed burning reduced …

Rapid Point-Of-Care Testing For Detection Of Antibodies To Toxoplasma Gondii In Black Vultures And Ring-Billed Gulls From Pennsylvania, Alexa Rosypal Von Dohlen, Sydney Randall, Jordyan Grays, Mark A. Dugo, Brian J. Hunt, Justin Brown, Kyle Van Why, Sawsan Ammar, Richard Gerhold

United States Department of Agriculture Wildlife Services: Staff Publications

Toxoplasma gondii is a zoonotic protozoan parasite that infects most warm-blooded animals, including birds. Scavenging birds are epidemiologically important hosts because they can serve as indicators of environmental T. gondii levels. A rapid point-of-care (POC) test that detects antibodies to T. gondii in humans is commercially available. In this research, we assessed the ability of the human POC test to detect anti–T. gondii antibodies in 106 black vultures (Coragyps atratus) and 23 ring-billed gulls (Larus delawarensis) from Pennsylvania, USA. Serum samples were tested with the POC test and compared to the modified …

Low Secondary Risks For Turkey Vultures From A Sodium Nitrite Toxic Bait For Wild Pigs, Justin A. Foster, John C. Kinsey, Michael J. Lavelle, Kurt C. Vercauteren, Nathan P. Snow

United States Department of Agriculture Wildlife Services: Staff Publications

An acute and orally‐delivered toxic bait for wild pigs (Sus scrofa) containing sodium nitrite (SN) is being developed and tested for potential registration in the U.S. We evaluated oral toxicity of SN and risk of secondary consumption in a common avian scavenger, the turkey vulture (Carthartes aura), by 1) conducting an acute oral toxicity test (LD₅₀) for turkey vultures by oral gavage, and 2) allowing turkey vultures to feed on whole carcasses and digestive tracts of wild pigs that died from consuming SN‐laden bait. Captive tests were conducted during fall 2016 and spring 2017 in the …

A Method For Characterizing Disease Emergence Curves From Paired Pathogen Detection And Serology Data, Joshua Hewitt, Grete Wilson-Henjum, Derek T. Collins, Jourdan M. Ringenberg, Christopher A. Quintanal, Robert Pleszewski, Jeffrey C. Chandler, Thomas J. Deliberto, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

1. Wildlife disease surveillance programs and research studies track infection and identify risk factors for wild populations, humans and agriculture. Often, several types of samples are collected from individuals to provide more complete information about an animal's infection history. Methods that jointly analyse multiple data streams to study disease emergence and drivers of infection via epidemiological process models remain underdeveloped. Joint-analysis methods can more thoroughly analyse all available data, more precisely quantifying epidemic processes, outbreak status, and risks.

2. We contribute a paired data modelling approach that analyses multiple samples from individuals. We use ‘characterization maps’ to link paired data …

Torque Teno Sus Virus 1: A Potential Surrogate Pathogen To Study Pig-Transmitted Transboundary Animal Diseases, Xiaolong Li, Brandon M. Parker, Raoul K. Boughton, James C. Beasley, Timothy J. Smyser, James D. Austin, Kim M. Pepin, Ryan S. Miller, Kurt C. Vercauteren, Samantha M. Wisely

United States Department of Agriculture Wildlife Services: Staff Publications

Understanding the epidemiology and transmission dynamics of transboundary animal diseases (TADs) among wild pigs (Sus scrofa) will aid in preventing the introduction or containment of TADs among wild populations. Given the challenges associated with studying TADs in free-ranging populations, a surrogate pathogen system may predict how pathogens may circulate and be maintained within wild free-ranging swine populations, how they may spill over into domestic populations, and how management actions may impact transmission. We assessed the suitability of Torque teno sus virus 1 (TTSuV1) to serve as a surrogate pathogen for molecular epidemiological studies in wild pigs by investigating …

Common Grackle (Quiscalus Quiscula) Predation Of A Great Lakes Piping Plover (Charadrius Melodus) Nest And Its Conservation Implications, Jade R. Arneson, Dennis A. Peloquin, Thomas G. Prestby, Sarah P. Saunders

United States Department of Agriculture Wildlife Services: Staff Publications

Common grackle (Quiscalus quiscula) was observed consuming eggs from an exclosed (protected) Great Lakes piping plover (Charadrius melodus) nest in the lower bay of Green Bay, Lake Michigan in Wisconsin, USA during June 2023. The observation, captured by a trail camera, is the first photographic documentation of grackle predation in any of the three piping plover breeding populations. This behavior adds common grackle to the suite of egg predators and has critical implications for this shorebird species, particularly in the Great Lakes region where piping plover is listed as federally endangered and common grackles are relatively …

Natural Selection On Feralization Genes Contributed To The Invasive Spread Of Wild Pigs Throughout The United States, Niek W. G. Barmentlo, Patrick G. Meirmans, William H. Stiver, Joseph G. Yarkovich, Blake E. Mccann, Antoinette J. Piaggio, Dominic Wright, Timothy J. Smyser, Mirte Bosse

United States Department of Agriculture Wildlife Services: Staff Publications

Despite a long presence in the contiguous United States (US), the distribution of invasive wild pigs (Sus scrofa × domesticus) has expanded rapidly since the 1980s, suggesting a more recent evolutionary shift towards greater invasiveness. Contemporary populations of wild pigs represent exoferal hybrid descendants of domestic pigs and European wild boar, with such hybridization expected to enrich genetic diversity and increase the adaptive potential of populations. Our objective was to characterize how genetic enrichment through hybridization increases the invasiveness of populations by identifying signals of selection and the ancestral origins of selected loci. Our study focused on invasive …