Veterinary Infectious Diseases Commons^™

Assessment Of Habitat‐Specific Competition For Oral Rabies Vaccine Baits Between Raccoons And Opossums, James L. Helton, Jacob E. Hill, David A. Bernasconi, Wesley C. Dixon, Richard B. Chipman, Amy Gilbert, James C. Beasley, Guha Dharmarajan, Olin E. Rhodes Jr.

United States Department of Agriculture Wildlife Services: Staff Publications

Throughout the eastern United States, the National Rabies Management Program (NRMP) distributes oral rabies vaccine (ORV) baits to manage rabies virus circulation in raccoon (Procyon lotor) populations. The consumption of vaccine baits by non‐target species including Virginia opossums (Didelphis virginiana) may reduce the effectiveness of ORV programs, but competition for baits remains poorly quantified in many areas of the southeastern United States. We distributed placebo ORV baits injected with a biomarker across 4 land cover types (bottomland hardwood, upland pine, riparian, isolated wetland) on the Savannah River Site in South Carolina, USA, 2017–2019. We then trapped …

Fusion Of Visible And Thermal Images Improves Automated Detection And Classification Of Animals For Drone Surveys, B. Santhana Krishnan, Landon R. Jones, Jared A. Elmore, Sathishkumar Samiappan, Kristine O. Evans, Morgan Pfeiffer, Bradley Blackwell, Raymond Iglay

United States Department of Agriculture Wildlife Services: Staff Publications

Visible and thermal images acquired from drones (unoccupied aircraft systems) have substantially improved animal monitoring. Combining complementary information from both image types provides a powerful approach for automating detection and classification of multiple animal species to augment drone surveys. We compared eight image fusion methods using thermal and visible drone images combined with two supervised deep learning models, to evaluate the detection and classification of white-tailed deer (Odocoileus virginianus), domestic cow (Bos taurus), and domestic horse (Equus caballus). We classified visible and thermal images separately and compared them with the results of image fusion. …

Spatial Ecology Of Translocated Raccoons, Jacob E. Hill, James L. Helton, Richard B. Chipman, Amy Gilbert, James C. Beasley, Guha Dharmarajan, Olin E. Rhodes

United States Department of Agriculture Wildlife Services: Staff Publications

Raccoons (Procyon lotor) are routinely translocated both legally and illegally to mitigate conflicts with humans, which has contributed to the spread of rabies virus across eastern North America. The movement behavior of translocated raccoons has important ramifications for disease transmission yet remains understudied and poorly quantified. To examine the spatial ecology of raccoons following experimental translocation, we performed reciprocal 16 km-distance translocations of 30 raccoons between habitats of high and low raccoon density (bottomland hardwood and upland pine, respectively) across the Savannah River Site (SRS) in Aiken, South Carolina, USA (2018–2019). Translocation influenced patterns of raccoon space use, …

Demographic, Environmental And Physiological Predictors Of Gastrointestinal Parasites In Urban Raccoons, Liana F. Wait, Shylo R. Johnson, Kathleen M. Nelson, Richard B. Chipman, Frederick E. Pogmore, Andrew P. Dobson, Andrea L. Graham

United States Department of Agriculture Wildlife Services: Staff Publications

Raccoons are host to diverse gastrointestinal parasites, but little is known about the ecology of these parasites in terms of their interactions with each other during coinfections, their interactions with host physiology and environmental factors, and their impact on raccoon health and survival. As a first step, we investigated the patterns of parasite infection and their demographic distribution in an urban-suburban population of raccoons trapped in the summers and autumns of 2018 and 2019. We collected faecal samples, demographic data, morphometric measurements, and blood smears, and used GPS data to classify trapping location by land cover type. Faecal floats were …

Livestock Producers' Perceptions Of The American Black Vulture Conflict In The Midwestern United States, Marian L. Wahl, Brooke Mcwherter, Patrick A. Zollner, Zhao Ma, Grant C. Burcham, Lee A. Humberg, Brian M. Kluever

United States Department of Agriculture Wildlife Services: Staff Publications

Human‐wildlife interactions are present wherever both humans and wildlife are found. Interactions can be positive or negative for humans and can include impacts that range from damage to property, agriculture, health and human safety, to emotional effects. Livestock‐wildlife interactions form a major component of human‐wildlife conflicts with foci often centered on the implications of livestock predation by wildlife. While most vulture species are obligate scavengers, several species, including the American black vulture (Coragyps atratus), may attack weak or newborn livestock. Black vulture populations and distributions are expanding in the Midwestern U.S., and attacks create a novel problem for …

The Influence Of Income And Loss On Hunters' Attitudes Towards Wild Pigs And Their Management, Samantha Leivers, Keith M. Carlisle, Rachel L. Connally, Maureen G. Frank, John M. Tomeček

United States Department of Agriculture Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) are one of the most pervasive invasive species in North America. Wild pigs pose a threat to crops, livestock, and the environment, but also provide recreational hunting opportunities. There are avenues for some stakeholder groups to generate income from wild pigs, however, stakeholders vary in attitudes towards wild pigs and their management. We investigated whether financial loss and income resulting from wild pigs influenced hunter stakeholder attitudes towards their management in Texas. We examined how land use influenced hunting landowner attitudes towards wild pigs. We analyzed 22,176 responses (8,707 landowners, 13,469 nonlandowners) fromTexas hunters …

Alternatives To Corn For Baiting Wild Pigs, Justin A. Foster, Lee H. Williamson, John C. Kinsey, Ryan L. Reitz, Kurt C. Vercauteren, Nathan P. Snow

United States Department of Agriculture Wildlife Services: Staff Publications

We examined dietary preferences of wild pigs to discern possible bait alternatives to corn. Captive trials were conducted during spring and fall 2021 in the Wild Pig Research Facility at Kerr Wildlife Management Area, Hunt, Texas, USA. We conducted 2‐choice tests by allowing wild pigs to feed ad libitum on soybeans, split peas, mealworms, and peanuts (spring 2021), and oats, acorns, earthworms, and peanuts (fall 2021), always with corn available as a second choice for reference. In each trial, we used proportion of test bait eaten versus total bait eaten, and relative access to both food sources as indices of …

Dispersal Of Blackbird Flocks From Sunflower Fields: Efficacy Influenced By Flock And Field Size But Not Drone Platform, Conor C. Egan, Bradley Blackwell, Esteban Fernández‐Juricic, Page Klug

United States Department of Agriculture Wildlife Services: Staff Publications

Crop depredation by blackbirds (Icteridae) results in substantial economic losses to the United States sunflower industry, and a solution to effectively reduce damage remains elusive. We evaluated the utility of uncrewed aircraft systems (UAS), or drones, as hazing tools to deter foraging blackbirds from commercial sunflower (Helianthus annuus) fields in North Dakota, USA, between September and October 2017. We compared the efficacy of 3 drones: a fixed‐wing predator model mimicking the form of an aerial raptor, a fixed‐wing airplane of similar size, and a multirotor drone. Multirotor drones are relatively easy to fly and are a multifunctional tool for agricultural …

A Novel Parakeet‐Selective Feeder For Control Of Invasive Psittacines, C. Jane Anderson, Eric A. Tillman, William P. Bukoski, Steven C. Hess, Leonard A. Brennan, Page E. Klug

United States Department of Agriculture Wildlife Services: Staff Publications

Over 40 species of parrots, members of order Psittaciformes, have established nonnative populations globally. Monk parakeets (Myiopsitta monachus) are among the most invasive bird species worldwide. In their introduced range, populations of monk parakeets have caused negative impacts on native species, habitats, economies, and human safety. Lethal population management has been complicated by the intelligence of monk parakeets, as they quickly alter behavior to avoid risks. Further, lethal control programs have been halted due to public controversy, as parakeets are highly charismatic. The contraceptive DiazaCon has been demonstrated to effectively reduce fertility in monk parakeets and other psittacines. In field …

Biodiversity Indices And Random Forests Reveal The Potential For Striped Skunk (Mephitis Mephitis) Fecal Microbial Communities To Function As A Biomarker For Oral Rabies Vaccination, Matthew W. Hopken, Darby Gilfillan, Amy Gilbert, Antoinette J. Piaggio, Mikaela Samsel Hilton, James Pierce, Bruce Kimball, Zaid Abdo

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife disease surveillance and monitoring poses unique challenges when assessing rates of population vaccination, immunity, or infection prevalence. Non-invasively detected biomarkers can help reduce risk to both animal and field personnel during wildlife disease management activities. In this study, we investigated the utility of fecal microbiome data collected from captive striped skunks (Mephitis mephitis) in predicting rabies virus vaccination and infection status. We sequenced the hypervariable region 4 (V4) of the bacterial 16S gene and estimated alpha and beta diversity across timepoints in three groups of skunks: vaccination then rabies virus infection, sham vaccination then rabies virus infection, and rabies …

Determination Of Residue Levels Of Rodenticide In Rodent Livers Offered Novel Diphacinone Baits By Liquid Chromatography-Tandem Mass Spectrometry, David A. Goldade, Shane Siers, Steven C. Hess, Robert T. Sugihara, Craig A. Riekena

United States Department of Agriculture Wildlife Services: Staff Publications

A specific and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of the anticoagulant rodenticide diphacinone (DPN) in mouse and rat liver. Tissue samples were extracted with a mixture of water and acetonitrile containing ammonium hydroxide. The extracted sample was cleaned up with a combination of liquid-liquid partitioning and dispersive solid phase extraction. Chromatographic separation was achieved using a Waters X-Bridge BEH C-18 LC column (50 mm, 2.1 mm ID, 2.5 μm particle size) with detection on a triple quadrupole mass spectrometer in multiple reaction monitoring (MRM) mode. The monitored transition for DPN was m/z …

Controllable Factors Affecting Accuracy And Precision Of Human Identification Of Animals From Drone Imagery, Landon R. Jones, Jared A. Elmore, B. Santhana Krishnan, Sathishkumar Samiappan, Kristine O. Evans, Morgan B. Pfeiffer, Brad Blackwell, Raymond Iglay

United States Department of Agriculture Wildlife Services: Staff Publications

Surveying animal populations using drones (unoccupied aircraft systems [UAS]) provides numerous advantages; however, few best practices exist to survey animal communities with drones. Among myriad factors that can affect human identification and counts of animals from drone images, we focused on three factors typically controlled in the study design or by the drone pilot: flight altitude, camera angle, and time of day. Identifying interactions and patterns among these three variables represents an important first step to determining best survey practices. We used a drone to survey known numbers of eight animal decoy species, representing a range of body sizes and …

Factors Affecting The Recovery Of Mexican Wolves In The Southwest United States, Stewart W. Breck, Amy J. Davis, John Oakleaf, David L. Bergman, Jim Devos, J. Paul Greer, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

1. Recovering and maintaining large carnivore populations is a global conservation challenge that requires better knowledge of the factors affecting their populations, particularly in shared landscapes (i.e. non-protected areas where people occupy and or utilize the land).
2. The Mexican wolf (Canis lupus baileyi) is an endangered wolf subspecies being recovered on shared landscapes in the Southwest United States and Mexico. We used data from the U.S. program to model population growth, evaluate the impact of management removal and illegal killing relative to other demographic factors, and test hypotheses about factors influencing rates of management removal and illegal killing.
3. From …

African Swine Fever, Vienna R. Brown, Julianna B. Lenoch, Courtney F. Bowden

United States Department of Agriculture Wildlife Services: Staff Publications

At the time of writing this chapter, a global pandemic of African swine fever (ASF) is ongoing with the virus having moved from Eastern Europe, Asia, and into the Caribbean—leaving swine production in devastation along the way. Due to the global spread of African swine fever virus (ASFV), the persistence of the virus, and the increasing number of endemic countries, this disease poses an imminent threat of introduction into North America and other countries that are currently ASF free. Throughout the chapter, we reference Eurasian wild boar (Sus scrofa) which are charismatic megafauna that are native to Europe and Asia. …

Spatially Structured Brown-Headed Cowbird Control Measures And Their Effects On Kirtland’S Warbler Long-Term Population Sustainability, Eric A. Margenau, Nathan W. Cooper, Donald J. Brown, Deahn M. Donner, Peter P. Marra, Pat Ryan

United States Department of Agriculture Wildlife Services: Staff Publications

Context: Brown-headed cowbirds (Molothrus ater), through brood parasitism, can exert extrinsic population growth pressures on North American songbirds. Cowbird removal programs may reduce parasitism rates on host species but can be expensive and difficult to implement throughout a host species’ breeding range.

Aim: We estimated cowbird abundance and nest parasitism rates within Kirtland’s warbler (Setophaga kirtlandii) primary breeding range in Michigan, USA, and determined the maximum sustainable parasitism rate for Kirtland’s warblers under several spatially structured cowbird removal designs.

Methods: We conducted point counts to estimate cowbird abundance and monitored nests to quantify nest parasitism rates …

Willingness To Pay For Reintroducing Wolves In A Divided Voting Base, Dana Lk Hoag, Jesse Burkhardt, Benjamin Ghasemi, Stewart W. Breck, Rebecca Niemiec, Kevin Crooks

United States Department of Agriculture Wildlife Services: Staff Publications

Wolves will soon be reintroduced in Colorado based on a statewide ballot initiative that narrowly passed in November 2020. Using an economic choice experiment, we estimate the benefits that wolf introduction might bring to Colorado. We calculated willingness to pay (WTP) for a sustainable wolf population by considering six program attributes: 1) state wolf population, 2) compensation for livestock-related losses, 3) cost-sharing for conflict reduction, 4) number of livestock killed statewide, 5) lethal government control of wolves, and 6) wolf hunting. Respondents who reported they voted yes on the ballot initiative had a positive WTP for a population of 200 …

Can Demographic Histories Explain Long-Term Isolation And Recent Pulses Of Asymmetric Gene Flow Between Highly Divergent Grey Fox Lineages?, Sophie Preckler-Quisquater, Elizabeth M. Kierepka, Dawn M. Reding, Antoinette J. Piaggio, Benjamin N. Sacks

United States Department of Agriculture Wildlife Services: Staff Publications

Secondary contact zones between deeply divergent, yet interfertile, lineages provide windows into the speciation process. North American grey foxes (Urocyon cinereoargenteus) are divided into western and eastern lineages that diverged approximately 1 million years ago. These ancient lineages currently hybridize in a relatively narrow zone of contact in the southern Great Plains, a pattern more commonly observed in smaller-bodied taxa, which suggests relatively recent contact after a long period of allopatry. Based on local ancestry inference with whole-genome sequencing (n = 43), we identified two distinct Holocene pulses of admixture. The older pulse (500–3500 YBP) reflected unidirectional …

Investigation Of Risk Factors For Introduction Of Highly Pathogenic Avian Influenza H5n1 Infection Among Commercial Turkey Operations In The United States, 2022: A Case-Control Study, Kelly A. Patyk, Victoria L. Fields, Andrea L. Beam, Matthew A. Branan, Rachel E. Mcguigan, Alice Green, Mia K. Torchetti, Kristina Lantz, Alexis Freifeld, Katherine Marshall, Amy H. Delgado

United States Department of Agriculture Wildlife Services: Staff Publications

Introduction: The 2022–2023 highly pathogenic avian influenza (HPAI) H5N1 outbreak in the United States (U.S.) is the largest and most costly animal health event in U.S. history. Approximately 70% of commercial farms affected during this outbreak have been turkey farms. Methods: We conducted a case-control study to identify potential risk factors for introduction of HPAI virus onto commercial meat turkey operations. Data were collected from 66 case farms and 59 control farms in 12 states. Univariate and multivariable analyses were conducted to compare management and biosecurity factors on case and control farms. Results: Factors associated with increased risk of infection …

Outbreak Of Epizootic Hemorrhagic Disease In Captive Reindeer (Rangifer Tarandus), Emma H. Torii, Arno Wünschmann, Mia Kim Torchetti, Leo Koster, Albert Van Geelen, Randy Atchison, Anne Rivas

United States Department of Agriculture Wildlife Services: Staff Publications

In September 2020, an outbreak of epizootic hemorrhagic disease occurred in captive reindeer (Rangifer tarandus) and was associated with neurological signs and mortality. Four reindeer died or were euthanized after acute illness over a 12-day period. Affected reindeer displayed abnormal behavior, neurologic signs, lethargy, and/or lameness. The most consistent gross finding was dark red streaks throughout the adrenal gland cortices (4/4). One animal had acute hemorrhage involving the subcutis and skeletal muscles over the ventrolateral body wall and back, and abomasal serosa. Histologically, the most common lesions were adrenal gland cortical hemorrhage (4/4) with necrosis (3/4) and lymphoplasmacytic meningoencephalitis with …

Investigation Of Risk Factors For Introduction Of Highly Pathogenic Avian Influenza H5n1 Virus Onto Table Egg Farms In The United States, 2022: A Case–Control Study, Alice L. Green, Matthew Branan, Victoria L. Fields, Kelly Patyk, Stephanie K. Kolar, Andrea Beam, Katherine Marshall, Rachel Mcguigan, Matthew Vuolo, Alexis Freifeld, Mia Kim Torchetti, Kristina Lantz, Amy H. Delgado

United States Department of Agriculture Wildlife Services: Staff Publications

Introduction: The 2022–2023 highly pathogenic avian influenza (HPAI) H5N1 outbreak in the United States (U.S.) is the most geographically extensive and costly animal health event in U.S. history. In 2022 alone, over 57 million commercial and backyard poultry in 47 U.S. states were affected. Over 75% of affected poultry were part of the commercial table egg production sector. Methods: We conducted a case–control study to identify potential risk factors for introduction of HPAI virus onto commercial table egg operations. Univariate and multivariable analyses were conducted to compare farm characteristics, management, and biosecurity factors on case and control farms. Results: Factors …