Veterinary Microbiology and Immunobiology Commons^™

Reemergence Of A Big Brown Bat Lyssavirus Rabies Variant In Striped Skunks In Flagstaff, Arizona, Usa, 2021–2023, Amy T. Gilbert, Lolita I. Van Pelt, Lias A. Hastings, Crystal M. Gigante, Lillian A. Orciari, Sabrina Kelley, Kathryn Fitzpatrick, René Edgar Condori, Yu Li, Scott Brunt, April Davis, Matthew W. Hopken, Clara C. P. Mankowski, Ryan M. Wallace, Charles E. Rupprecht, Richard B. Chipman, David L. Bergman

United States Department of Agriculture Wildlife Services: Staff Publications

Background

Throughout the Americas, Lyssavirus rabies (RV) perpetuates as multiple variants among bat and mesocarnivore species. Interspecific RV spillover occurs on occasion, but clusters and viral host shifts are rare. The spillover and host shift of a big brown bat (Eptesicus fuscus) RV variant Ef-W1 into mesocarnivores was reported previously on several occasions during 2001–2009 in Flagstaff, Arizona, USA, and controlled through rabies vaccination of target wildlife. During autumn 2021, a new cluster of Ef-W1 RV cases infecting striped skunks (Mephitis mephitis) was detected from United States Department of Agriculture enhanced rabies surveillance in Flagstaff. The …

Prevalence Of Avian Influenza Virus In Atypical Wild Birds Host Groups During An Outbreak Of Highly Pathogenic Strain Ea/Am H5n1, Jourdan M. Ringenberg, Kelsey Weir, Lee Humberg, Carl Voglewede, Mitch Oswald, J. Jeffrey Root, Krista Dilione, Even Casey, Michael Milleson, Timothy Linder, Juliann Lenoch

United States Department of Agriculture Wildlife Services: Staff Publications

The global outbreak of highly pathogenic avian influenza (HPAI) H5N1 Eurasian lineage goose/Guangdong clade 2.3.4.4b virus that was detected in North America in 2021 is the largest in history and has significantly impacted wild bird populations and domestic poultry across the continent. Synanthropic birds may play an important role in transmitting the virus laterally to other wild bird species and domestic poultry. Understanding the dynamics of HPAI in atypical, or nonreservoir, wild bird hosts may help inform management decisions and potential risk factors to both wild and domestic bird populations. Following the confirmation of infections of HPAI H5N1 in domestic …

Population Response Of Eastern Wild Turkey To Removal Of Wild Pigs, Matthew T. Mcdonough, Stephen J. Zenas, Robert A. Gitzen, Mark D. Smith, Kurt C. Vercauteren, Stephen S. Ditchkoff

United States Department of Agriculture Wildlife Services: Staff Publications

There is insufficient understanding of interspecific interactions with the eastern wild turkey (Meleagris gallopavo silvestris) and wild pigs (Sus scrofa). Wild pigs compete with wild turkeys and predate nests and adults; however, population‐level effects on wild turkeys are not clear. Using cameras, we assessed responses of wild turkey populations to wild pig removal in central Alabama, USA, from 2018–2021. We compared wild turkey relative abundance and occupancy on 3 large‐scale pigremoval treatment sites (3,407–5,531 ha) relative to a control site (2,510 ha) during 1 pre‐treatment year and 2 posttreatment years, with analyses including a covariate expressing the cumulative …

Evaluation Of Mitigation Translocation As A Management Tool To Reduce Conflicts Between Humans And American Kestrels, Brian E. Washburn

United States Department of Agriculture Wildlife Services: Staff Publications

Raptor‐aircraft collisions (bird strikes) pose a serious safety risk to civil aircraft. Even smaller raptors, such as American kestrels (Falco sparverius), can be problematic within airport environments. Given widespread declines in kestrel populations, public interest, logistical and financial constraints, and other factors, managing kestrels at airports presents some unique challenges. I conducted a study to determine which biological (e.g., age and sex of the bird) and logistical factors (e.g., month and translocation distance) might influence the return of American kestrels live‐captured and translocated from 42 civil airports and military airbases within the contiguous USA during 2016–2021. American kestrels …

Temporal And Spatial Influences On Fawn Summer Survival In Pronghorn Populations: Management Implications From Noninvasive Monitoring, Cole A. Bleke, Eric M. Gese, Juan J. Villalba, Shane B. Roberts, Susannah S. French

United States Department of Agriculture Wildlife Services: Staff Publications

Monitoring vital rates allowsmanagers to estimate trends in growth rates of ungulate populations. However, connecting the influence of nutrition on ungulate demography is challenging. Noninvasive sampling offers a low-cost, low-effort alternative for measuring nutritional indices, allowing for an increased understanding of the mechanistic relationships between environmental factors, nutrition, and specific population vital rates. We examined the temporal influence of intrinsic and extrinsic factors on pronghorn (Antilocapra americana) fawn recruitment. We collected fresh fecal samples from adult female pronghorn in five subpopulations spanning three sampling periods associated with critical maternal life-history stages (late gestation, early lactation, breeding season) for …

Discovery Of A Novel Invasive Rodent Species On Wake Atoll With A Desert Southwest Usa Origin, Antoinette J. Piaggio, Eric Lanners, Daniel R. Taylor, Aaron B. Shiels, Marjorie Matocq, John Eisemann

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive species, particularly omnivorous rodents, have damaged island ecosystems around the world. The unique flora and fauna of island systems have typically not evolved with omnivorous rodents and are heavily impacted by their introduction. Wake Atoll of the southern Pacific Ocean is a 707-hectare coral island complex of three islands managed by the United States Department of Defense (DoD). DoD restricts civilian access to the atoll but aircraft and seacraft regularly visit the island to transport military equipment and to sustain the year-round military and contractor personnel stationed on the atoll. Wake Atoll had been invaded by Rattus rattus complex …

Trichinella Murrelli Identified In Red Foxes (Vulpes Vulpes) In Pennsylvania, Usa, Jitender Dubey, Peter C. Thompson, Larissa S. De Araujo, Aditya Gupta, Sasha Kay, Oliver C. H. Kwok, Jaquin Battle, Kyle R. Van Why, Justin D. Brown, Benjamin Rosenthal

United States Department of Agriculture Wildlife Services: Staff Publications

Trichinella infections have been eliminated from pork where pigs are raised in biosecure facilities, but wildlife infections persist. Trichinella murrelli is the primary zoonotic species in wild carnivores in the United States, having been identified in several species of omnivores and carnivores. Here, we document its occurrence in seven of 21 (33.3%) red foxes (Vulpes vulpes) from six counties in Pennsylvania. Encysted Trichinella juveniles were detected in muscle squashes (< 5 g samples) of all seven foxes, and in histological sections of the tongue and limb muscle of three. Juveniles from muscle squashes were pooled and tested in a multiplex PCR capable of differentiating all Trichinella species native to the USA; all samples contained only T. murrelli. This is the first identification of T. murrelli in red foxes from Pennsylvania, …

Heating Decoys To Mimic Thermal Signatures Of Live Animals For Drones, Landon R. Jones, Cerise Mensah, Jared S. Elmore, Kristine O. Evans, Morgan B. Pfeiffer, Brad F. Blackwell, Raymond B. Iglay

United States Department of Agriculture Wildlife Services: Staff Publications

Method name

Heating animal decoys to mimic thermal signatures for drones

Abstract

Thermal sensors mounted on drones (unoccupied aircraft systems) are popular and effective tools for monitoring cryptic animal species, although few studies have quantified sampling error of ani- mal counts from thermal images. Using decoys is one effective strategy to quantify bias and count accuracy; however, plastic decoys do not mimic thermal signatures of representative species. Our objective was to produce heat signatures in animal decoys to realistically match thermal images of live animals obtained from a drone-based sensor. We tested commercially available methods to heat plastic decoys of …

Competitive Behaviors Between Black Vultures (Coragyps Atratus) And Turkey Vultures (Cathartes Aura) During Scavenging / Comportamientos Competitivos Entre Coragyps Atratus Y Cathartes Aura Durante El Carroñeo, Amanda M. Herbert, Patrick A. Zollner, Landon R. Jones, Marian L. Wahl, Grant N. Burcham, Bryan M. Kluever, Lee A. Humberg, Brandon M. Quinby

United States Department of Agriculture Wildlife Services: Staff Publications

Abstract

Interference competition occurs when an individual prohibits another’s access to a resource through antagonistic interactions. Despite considerable research on scavenger interactions at carrion, the limited evidence for competitive interactions between black vultures (Coragyps atratus) and turkey vultures (Cathartes aura) relies upon the frequency of antagonistic interactions without considering other forms of competition. Using remote cameras, we recorded the duration of aggression, scavenging, and vigilance behaviors exhibited by individual black vultures and turkey vultures scavenging stillborn domestic cattle carcasses within flocks composed of one or both vulture species. We tested for differences of durations of each …

Efficacy Of Gonacon Fertility Control Against Prairie Dogs And Potential For Uses On Other Rodent Species, Aaron B. Shiels, Emily W. Ruell, Jason E. Bruemmer

United States Department of Agriculture Wildlife Services: Staff Publications

Use of a contraceptive (i.e., fertility control) is attractive for rodent management where lethal control is unwanted. Although population reduction is generally unachievable with small-scale, short-term contraceptive use, reduced juvenile recruitment is achievable. The injectable immunocontraceptive vaccine GonaCon (active ingredient: gonadotropin releasing hormone [GnRH]) was registered in 2022 by the United States Environmental Protection Agency (EPA) for controlling fertility of female prairie dogs (Cynomys, a type of ground squirrel) in urban/suburban settings. Here we: 1) describe past research, including a replicated field study in Colorado (GonaCon treatment vs. control sites) testing efficacy of GonaCon in prairie dogs, which …

Agricultural And Ecological Resources Safeguarded By The Prevention Of Wild Pig Population Expansion, Colin Jareb, Kim M. Pepin, Ryan S. Miller, Stephanie A. Shwiff, Sophie C. Mckee

United States Department of Agriculture Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) are one of the most destructive invasive species in the United States, known for causing extensive damage to agricultural commodities, natural resources, and property, and for transmitting diseases to livestock. Following the establishment of the National Feral Swine Damage Management Program (NFSDMP) in 2014, the expansion of wild pig populations has been successfully slowed. This paper combines two modeling approaches across eight separate models to characterize the expansion of wild pig populations in the absence of intervention by the NFSDMP and forecasts the value of a subset of resources safeguarded from the threat of …

Surveillance Of Highly Pathogenic Avian Influenza Virus In Wild Canids From Pennsylvania, Usa, Kevin D. Niedringhaus, Taylor C. Chan, Ashley Mcdowell, Lauren Mxwell, Madison Stevens, Lane Potts, Erica Miller, Eman Anis, Kyle Van Why, Thomas Keller, David Stallknecht, Rebecca L. Poulson, Kaitlyn Bahrs, Justin D. Brown

United States Department of Agriculture Wildlife Services: Staff Publications

The avian influenza virus is a global pathogen with significant health and economic implications. While primarily a pathogen of wild and domestic birds, recent outbreaks of the H5N1 highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.4b have caused mortality in a wide variety of mammals, including members of the Canidae family, on multiple continents. Despite sporadic mortality events globally, the epidemiology and pathobiology of H5N1 HPAIV in wild canids remains poorly defined. During 2022–2024, 41 wild canid carcasses (diagnostic cases), including 23 red foxes and 18 gray foxes, were tested for the influenza A virus (IAV) via PCR, with five …

Rabies, Amy T. Gilbert, Christine Ellis

United States Department of Agriculture Wildlife Services: Staff Publications

Illustrated fact sheet on rabies.

Oral Rabies Vaccination Of Raccoons (Procyon Lotor) Across A Development Intensity Gradient In Burlington, Vermont, Usa, 2015–2017, Emily M. Beasley, Kathleen M. Nelson, Dennis Slate, Amy T. Gilbert, Frederick E. Pogmore, Richard B. Chipman, Amy J. Davis

United States Department of Agriculture Wildlife Services: Staff Publications

Management of the raccoon rabies virus variant in North America is conducted primarily using oral rabies vaccination (ORV). When a sufficient proportion of the population is vaccinated (60%), rabies transmission can be eliminated. To date, ORV programs have successfully controlled and eliminated raccoon rabies in rural areas, but there has been less success in urban areas. We studied the proportions of rabies virus neutralizing antibodies (RVNA) in a raccoon (Procyon lotor) population during a 3-year ORV trial in developed areas of Burlington, Vermont, United States. We used a modified N-mixture model to estimate raccoon abundance, RVNA seroprevalence, and …

Assessing The Efficiency Of Local Rabies Vaccination Strategies For Raccoons (Procyon Lotor) In An Urban Setting, Guillaume Bastille-Rousseau, Nicole T. Gorman, Katherine M. Mcclure, Larissa Nituch, Tore Buchanan, Richard B. Chipman, Amy T. Gilbert, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Raccoon rabies virus (RRV) has been managed using multiple vaccination strategies, including oral rabies vaccination and trap-vaccinate-release (TVR). Identifying a rabies vaccination strategy for an area is a nontrivial task. Vaccination strategies differ in the amount of effort and monetary costs required to achieve a particular level of vaccine seroprevalence (efficiency). Simulating host movement relative to different vaccination strategies in silico can provide a useful tool for exploring the efficiency of different vaccination strategies. We refined a previously developed individual-based model of raccoon movement to evaluate vaccination strategies for urban Hamilton, Ontario, Canada. We combined different oral rabies vaccination baiting …

Ethyl-Iophenoxic Acid As A Serum Marker For Oral Baiting Of Tasmanian Devils, Ruth Pye, David Nichols, Sally A. Nofs, Amy T. Gilbert, Andrew S. Flies

United States Department of Agriculture Wildlife Services: Staff Publications

Oral baits containing vaccines, medicants or toxicants have been delivered to a broad range of wildlife species to protect against or treat disease, or suppress populations. Ethyl-Iophenoxic acid (Et-IPA) is used as a biomarker to determine oral bait consumption by wildlife species to assess and refine baiting strategies. Et-IPA is a persistent biomarker in many eutherian mammal species but not in the two marsupial species, swamp wallaby (Wallabia bicolor) and brushtail possum (Trichosurus vulpecula), tested to date. Et-IPA has not previously been evaluated in carnivorous marsupials. The Tasmanian devil (Sarcophilus harrisii), the largest extant …

Estimating Landscape Spread Of A Low-Prevalence Disease Using Multiple Surveillance Methods, Abigail Feuka, Aakash Pandey, Melinda Cosgrove, Megan Moriarty, Anthony Duffiney, Henry Campa Iii, Kurt C. Vercuteren, Kimberly M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

1. Diseases occurring at low prevalence in free-ranging wildlife can be difficult to study and predict at a landscape scale. This problem is compounded by imperfect pathogen detection.

2. We used data from multiple surveillance methods to determine factors influencing spread of a low-prevalence disease, bovine tuberculosis (bTB), among white-tailed deer (Odocoileus virginianus) in a bTB endemic area over a 10-year period. We fit dynamic occupancy models to predict spatial spread of bTB through a county in Michigan, USA, within the bTB endemic area, while accounting for imperfect detection and a suite of ecological processes potentially driving bTB …

Probabilistic Genetic Identification Of Wild Boar Hybridization To Support Control Of Invasive Wild Pigs (Sus Scrofa), Timothy J. Smyser, Peter Pfaffelhuber, Rachael M. Giglio, Matthew G. Desaix, Amy J. Davis, Courtney F. Bowden, Michael A. Tabak, Arianna Manunza, Valentin Adrian Bâlteanu, Marcel Amills, Laura Iacolina, Pamela Walker, Carl Lessard, Antoinette J. Piaggio

United States Department of Agriculture Wildlife Services: Staff Publications

The rapid expansion of wild pigs (Sus scrofa) throughout the United States has been fueled by unlawful introductions, with invasive populations causing extensive crop losses, damaging native ecosystems, and serving as a reservoir for disease. Multiple states have passed laws prohibiting the possession or transport of wild pigs. However, genetic and phenotypic similarities between domestic pigs and invasive wild pigs—which overwhelmingly represent domestic pig and wild boar hybrids—pose a challenge for the enforcement of such regulations. We sought to exploit wild boar ancestry as a common attribute among the vast majority of invasive wild pigs as a means …

Effects Of Pregnancy Prevention On Brucella Abortus Shedding In American Bison (Bison Bison), Pauline Nol, Rebecca Frey, Morgan Wehtje, Jack C. Rhyan, Patrick Ryan Clarke, Matthew Mccollum, Christine Quance, Douglas C. Eckery, Suelee Robbe-Austerman

United States Department of Agriculture Wildlife Services: Staff Publications

Products of parturition are the predominant source of Brucella abortus for transmission in bison (Bison bison). Our objective was to assess whether preventing pregnancy in Brucella-seropositive bison reduced B. abortus shedding. Brucella-seropositive and -seronegative bison from Yellowstone National Park, Wyoming, USA were used in a replicated experiment. Each of two replicates (rep1, rep2) included a group of seropositive females treated with a single dose of gonadotropin-releasing hormone-based immunocontraceptive (Treatment rep1, n = 15; Treatment rep2, n = 20) and an untreated group (Control rep1, n = 14; Control rep2, …

Effects Of The Immunocontraceptive Gonacon On Pregnancy In Brucella-Seropositive American Bison (Bison Bison), Rebecca K. Frey, Morgan E. Wehtje, Pauline Nol, Patrick R. Clarke, Jack C. Rhyan, Matthew P. Mccollum, Lowell A. Miller, Douglas C. Eckery

United States Department of Agriculture Wildlife Services: Staff Publications

The purpose of this study was to determine if the number of pregnancies in naturally infected Brucella abortus-positive bison (Bison bison) cows would be reduced over a period of 5 yr after one treatment with 3000 mg gonadotropin-releasing hormone immunocontraceptive (GonaCon) compared to a similar group of naturally infected B. abortus-positive bison cows not treated with GonaCon. In each of the 5 yr, GonaCon-treated cows produced fewer offspring in relation to number of cows than the nontreated cows. Fisher’s Exact test comparing offspring produced during the first reproductive season showed a significant difference between the …