Veterinary Preventive Medicine, Epidemiology, and Public Health Commons^™

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 …

Raccoons (Procyon Lotor) Show Higher Trypanosoma Cruzi Detection Rates Than Virginia Opossums (Didelphis Virginiana) In South Carolina, Usa, David A. Bernasconi, Madison L. Miller, Jacob E. Hill, Pooja Gupta, Richard Chipman, Amy Gilbert, Olin E. Rhodes Jr., Guha Dharmarajan

United States Department of Agriculture Wildlife Services: Staff Publications

Chagas disease, a significant public health concern in the Americas, is caused by a protozoan parasite, Trypanosoma cruzi. The life cycle of T. cruzi involves kissing bugs (Triatoma spp.) functioning as vectors and mammalian species serving as hosts. Raccoons (Procyon lotor) and opossums (Didelphis virginiana) have been identified as important reservoir species in the life cycle of T. cruzi, but prevalence in both species in the southeastern United States is currently understudied. We quantified T. cruzi prevalence in these two key reservoir species across our study area in South Carolina, USA, and …

Rabies Virus Serosurvey Of The Small Indian Mongoose (Urva Auropunctata) Across Multiple Habitats In Puerto Rico, 2014–21, Are R. Berentsen, Mel J. Rivera-Rodriguez, Fabiola B. Torres-Toledo, Amy J. Davis, Richard Chipman, Amy Gilbert

United States Department of Agriculture Wildlife Services: Staff Publications

The small Indian mongoose (Urva auropuncata) is a rabies reservoir in Puerto Rico and accounts for over 70% of reported animal rabies cases annually. The presence of rabies virus-neutralizing antibodies (RVNA) is often used as a tool to measure exposure to rabies virus in wildlife populations. We conducted a serosurvey of mongooses at 11 sites representing six habitat types across Puerto Rico. We collected a serum sample from 464 individual mongooses during 2014–2021. Overall, 80/464 (17.0%; 95% confidence interval, 14.1–20.9%; 55 male, 23 female, and two sexes not recorded) of individual mongooses sampled across all habitats were RVNA …

Predicting Dispersal And Conflict Risk For Wolf Recolonization In Colorado, Mark A. Ditmer, George Wittemyer, Katherine A. Zeller, Stewart W. Breck, Robert J. Fletcher Jr., Kevin R. Crooks

United States Department of Agriculture Wildlife Services: Staff Publications

1. The colonization of suitable yet unoccupied habitat due to natural dispersal or human introduction can benefit recovery of threatened species. Predicting habitat suitability and conflict potential of colonization areas can facilitate conservation planning.

2. Planning for reintroduction of gray wolves (Canis lupus) to the United States state of Colorado is underway. Assessing which occupancy sites minimize the likelihood of human-wolf conflict during dispersal events and seasonal movements is critical to the success of this initiative.

3. We used a spatial absorbing Markov chain (SAMC) framework, which extends random walk theory and probabilistically accounts for both movement behavior …

Straight From The Coyote’S Mouth: Genetic Identification Of Prey Through Oral Swabs Of Predators, Julie K. Young, Amanda M. Mast, James A. Walton, Torrey Rodgers, Antionette J. Piaggio, Daniel R. Taylor, Karen E. Mock

United States Department of Agriculture Wildlife Services: Staff Publications

Human-carnivore conflicts often involve the depredation of domestic livestock. These depredation events are rarely observed, yet mitigation typically involves identifying the species or individual involved for removal or relocation. We tested a molecular method to identify individuals involved in depredation events using mouth swabs to determine if prey DNA could be detected, and for how long. We fed mule deer Odocoileus hemionus meat to captive coyotes Canis latrans and swabbed their mouths at five predetermined intervals between 2–72 h after consumption of the deer meat. We assessed two different molecular forensic methods to analyze the saliva swabs: qPCR for species …

Development And Evaluation Of Prototype Toxicant-Delivery Bait Stations For The Control Of The Small Indian Mongoose, Carmen C. Antaky, Robert T. Sugihara, Israel L. Leinbach, Shane R. Siers, Emily W. Ruell, Steven C. Hess

United States Department of Agriculture Wildlife Services: Staff Publications

We conducted research to develop a safe and effective toxic bait to control the small Indian mongoose (Urva auropunctata), an invasive vertebrate predator impacting the survival of native species in Hawai‘i (United States) and in other parts of the world. A preserved fish-based bait product was found to be highly palatable to mongooses in cage trials and subsequent formulations with diphacinone (0.005%) showed promise as an efficacious toxic bait for mongooses. This product is intended for future use to control mongooses in conservation and urban areas, and as a biosecurity tool at ports of entry to address accidental …

Environmental Transmission Of Influenza A Virus In Mallards, Kim M. Pepin, Clinton B. Leach, Nicole L. Barrett, Jeremy W. Ellis, Kaci K. Vandalen, Colleen T. Webb, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

Abstract

Influenza A viruses present a major challenge for animal and human health. They circulate widely in wild waterfowl and frequently spillover into poultry, emphasizing the need for risk-based surveillance in wild birds and an understanding of the relative importance of different transmission mechanisms. We addressed this objective with a replicated (N = 6) experimental infection study in which we serially exposed eight cohorts of four naïve contact mallards to an experimentally infected mallard and a shared water pool. Viral concentration in the water was a better predictor of transmission than several direct measures of viral shedding in the …

Genomic Regions Associated With Pseudorabies Virus Infection Status In Naturally Infected Feral Swine (Sus Scrofa), Courtney F. Bowden, Jennifer N. Kiser, Ryan S. Miller, Alexandra C. Buckley, Paola M. Boggiatto, Rachael M. Giglio, Vienna R. Brown, Dorian Garrick, Holly L. Neibergs, Antoinette J. Piaggio, Scott E. Speidel, Timothy J. Smyser

United States Department of Agriculture Wildlife Services: Staff Publications

Pseudorabies virus (PRV)—the causative agent of Aujeszky’s disease—was eliminated from commercial pig production herds in the United States (US) in 2004; however, PRV remains endemic among invasive feral swine (Sus scrofa). The circulation of PRV among abundant, widespread feral swine populations poses a sustained risk for disease spillover to production herds. Risk–based surveillance has been successfully implemented for PRV in feral swine populations in the US. However, understanding the role of host genetics in infection status may offer new insights into the epidemiology and disease dynamics of PRV that can be applied to management strategies. Genetic mechanisms underlying …

Estimating Northern Spotted Owl (Strix Occidentalis Caurina) Pair Detection Probabilities Based On Call-Back Surveys Associated With Long-Term Mark-Recapture Studies, 1993–2018, Katie M. Dugger, Alan B. Franklin, Damon B. Lesmeister, Raymond J. Davis, J. David Wiens, Gary C. White, James D. Nichols, James E. Hines, Charles B. Yackulic, Carl J. Schwarz, Steven A. Ackers, L. Steven Andrews, Larissa L. Bailey, Robin Bown, Jesse Burgher, Kenneth P. Burnham, Peter C. Carlson, Tara Chestnut, Mary M. Conner, Krista E. Dilione, Eric D. Forsman, Scott A. Gremel, Keith A. Hamm, Dale R. Herter, J. Mark Higley, Rob B. Horn, Julianna M. Jenkins, William L. Kendall, David W. Lapmphear, Christopher Mccafferty, Trent L. Mcdonald, Janice A. Reid, Jeremy T. Rockweit, David C. Simon, Stan G. Sovern, James K. Swingle, Heather Wise

United States Department of Agriculture Wildlife Services: Staff Publications

The northern spotted owl (Strix occidentalis caurina; hereinafter NSO) was listed as “threatened” under the Endangered Species Act in 1990 and population declines have continued since that listing. Given the species’ protected status, any proposed activities on Federal lands that might impact NSO require consultation with U.S. Fish and Wildlife Service and part of that consultation often includes surveys to determine presence and occupancy status of the species in the proposed activity area. The objective of this report is to present study-area specific estimates of the probability of detection for NSO pairs from twelve 2-week seasonal survey periods …

Light Wavelength And Pulsing Frequency Affect Avoidance Responses Of Canada Geese, Ryan B. Lunn, Patrice E. Baumhardt, Bradley F. Blackwell, Jean Paul Freyssinier, Esteban Fernández-Juricic

United States Department of Agriculture Wildlife Services: Staff Publications

Collisions between birds and aircraft cause bird mortality, economic damage, and aviation safety hazards. One proposed solution to increasing the distance at which birds detect and move away from an approaching aircraft, ultimately mitigating the probability of collision, is through onboard lighting systems. Lights in vehicles have been shown to lead to earlier reactions in some bird species but they could also generate attraction, potentially increasing the probability of collision. Using information on the visual system of the Canada goose (Branta canadensis), we developed light stimuli of high chromatic contrast to their eyes. We then conducted a controlled …

Assessment Of Spilled Toxic Bait By Wild Pigs And Potential Risk To Non-Target Species, John C. Kinsey, Justin A. Foster, Nathan P. Snow, Jason D. Wishart, Linton D. Staples, Janis K. Bush, Kurt V. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Background

In 2018, a sodium nitrite (SN)-based toxic bait for invasive wild pigs (hereafter wild pigs; Sus scrofa), was evaluated to determine its effectiveness in reducing local wild pig populations in Texas. Localized population reductions of > 70% were achieved, but spillage of bait outside wild pig-specific feeders (bait stations) caused by feeding wild pigs resulted in the deaths of non-target animals. To evaluate risks to non-target animals, we tested whether bait presentation influenced the total amount of bait spilled by wild pigs and estimated the associated risk to non-target species.

Results

We found that bait spilled outside bait stations …

Population Density Of The Small Indian Mongoose (Urva Auropunctata) Across Multiple Habitat Types And Seasons In Puerto Rico, Are R. Berentsen, Caroline C. Sauvé, Mel J. Rivera-Rodriguez, Fabiola B. Torres-Toledo, Richard B. Chipman, Amy T. Gilbert

United States Department of Agriculture Wildlife Services: Staff Publications

The small Indian mongoose (Urva auropunctata) is a rabies reservoir on several Caribbean Islands including Puerto Rico. In the continental United States, oral rabies vaccination (ORV) has been used to control and locally eliminate rabies viruses targeting meso-carnivores including raccoons (Procyon lotor), grey foxes (Urocyon cinereoargenteus), and coyotes (Canis latrans), and has more recently been proposed to mitigate and control mongoose rabies in Puerto Rico. A fundamental understanding of the population density of the target species is an important factor in planning bait application rates prior to ORV operations. In Puerto Rico, …

Changes In Wild Pig (Sus Scrofa) Relative Abundance, Crop Damage, And Environmental Impacts In Response To Control Efforts, Joseph W. Treichler, Kurt C. Vercauteren, Charles R. Taylor, James C. Beasley

United States Department of Agriculture Wildlife Services: Staff Publications

Background

As the population and range of wild pigs (Sus scrofa) continue to grow across North America, there has been an increase in environmental and economic damages caused by this invasive species, and control efforts to reduce damages have increased concomitantly. Despite the expanding impacts and costs associated with population control of wild pigs, the extent to which wild pig control reduces populations and diminishes environmental and agricultural damages are rarely quantified.The goal of this study is to quantify changes in wild pig relative abundance and subsequent changes in damages caused by invasive wild pigs in response to …

Risk Of African Swine Fever Virus Transmission Among Wild Boar And Domestic Pigs In Poland, Kim M. Pepin, Tomasz Borowik, Maciej Frant, Kamila Plis, Tomasz Podgórski

United States Department of Agriculture Wildlife Services: Staff Publications

Introduction

African swine fever (ASF) is a notifiable disease of swine that impacts global pork trade and food security. In several countries across the globe, the disease persists in wild boar (WB) populations sympatric to domestic pig (DP)operations, with continued detections in both sectors. While there is evidence of spillover and spillback between the sectors, the frequency of occurrence and relative importance of different risk factors for transmission at the wildlife-livestock interface remain unclear.

Methods

To address this gap, we leveraged ASF surveillance data from WB and DP across Eastern Poland from 2014–2019 in an analysis that quantified the relative …

Changes In Fecal Glucocorticoid Metabolites In Captive Coyotes (Canis Latrans): Influence Of Gender, Time, And Reproductive Status, Eric M. Gese, Patricia A. Terletzky, Cole A. Bleke, Erika T. Stevenson, Susannah S. French

United States Department of Agriculture Wildlife Services: Staff Publications

Simple summary

Biologists have long considered producing offspring a demanding time in the life of any animal, with reproducing and raising offspring being physiologically stressful. We examined whether breeding and producing pups was more stressful than other life-history stages among captive coyotes (Canis latrans) using fecal sampling and subsequent assays for glucocorticoid metabolites. Using 12 pairs of coyotes (five pairs produced pups, seven pairs did not), we examined fecal glucocorticoid metabolites (fGCM) covering 11 biological time periods for one year. We found high individual variability among both females and males with no apparent statistical effect of reproduction on …

Individual‑Level Patterns Of Resource Selection Do Not Predict Hotspots Of Contact, Anni Yang, Raoul Boughton, Ryan S. Miller, Nathan P. Snow, Kurt C. Vercauteren, Kim C. Pepin, George Wittemyer

United States Department of Agriculture Wildlife Services: Staff Publications

Contact among animals is crucial for various ecological processes, including social behaviors, disease transmission, and predator–prey interactions. However, the distribution of contact events across time and space is heterogeneous, influenced by environmental factors and biological purposes. Previous studies have assumed that areas with abundant resources and preferred habitats attract more individuals and, therefore, lead to more contact. To examine the accuracy of this assumption, we used a use-available framework to compare landscape factors influencing the location of contacts between wild pigs (Sus scrofa) in two study areas in Florida and Texas (USA) from those influencing non-contact space use. …

Differential Canid Predation Of Translocated Juvenile Desert Tortoises (Gopherus Agassizii) Using Chemical Signature Differences, Derek B. Hall, Bruce A. Kimball, Jennifer M. Germano, Eric M. Gese, Jeanette A. Perry

United States Department of Agriculture Wildlife Services: Staff Publications

Differential predation was observed in a population of 59 translocated juvenile desert tortoises (Gopherus agassizii) of known sex during a juvenile translocation survival study between September 2012 and November 2017. The main source of mortality was attributed to coyote (Canis latrans) and kit fox (Vulpes macrotis) predation. Predation was skewed with higher female mortality than male mortality. We tested the hypothesis that juvenile females smell different than males, which leads to increased canid predation. We also explored differences in chemical signatures of resident adult female and male desert tortoises. We collected oral, cloacal, and …

Home Range Overlap Between Small Indian Mongooses And Free Roaming Domestic Dogs In Puerto Rico: Implications For Rabies Management, Caroline C. Sauvé, Are R. Berentsen, Steven F. Llanos, Amy T. Gilbert, Patrick A. Leighton

United States Department of Agriculture Wildlife Services: Staff Publications

The small Indian mongoose (Urva auropunctata) is the primary terrestrial wildlife rabies reservoir on at least four Caribbean islands, including Puerto Rico. In Puerto Rico, mongooses represent a risk to public health, based on direct human exposure and indirectly through the transmission of rabies virus to domestic animals. To date, the fundamental ecological relationships of space use among mongooses and between mongooses and domestic animals remain poorly understood. This study is the first to report mongoose home range estimates based on GPS telemetry, as well as concurrent space use among mongooses and free roaming domestic dogs (FRDD; Canis …

Type And Frequency Of Wild Pig-Domestic Livestock Contacts And Operator Concern For Disease Spread, Sophie C. Mckee, Daniel F. Mooney, Ryan S. Miller

United States Department of Agriculture Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) can levy substantial costs to domestic livestock operations and global supply chains due to disease introduction. Producers can take defensive action to avert these costs, but the factors influencing these decisions are not well understood. We examined survey data to characterize the type and frequency of contacts between wild pigs and domestic livestock and investigated the determinants of farm operator concern for disease introduction using an ordered logit model. We found that operators with livestock kept in buildings were more concerned about disease than those with livestock kept in fenced areas or that roam …

Hepatozoon Spp. Infection In Wild Canids In The Eastern United States, Eliza Baker, Alex Clemson, Debra Miller, Kayla Buck Garrett, Christopher A. Cleveland, Justin Brown, Kyle Van Why, Richard W. Gerhold Jr.

United States Department of Agriculture Wildlife Services: Staff Publications

Background Hepatozoon spp. are apicomplexan parasites known to cause musculoskeletal disease in a variety of animals. Two species are known to infect wild and domestic canids in the United States: Hepatozoon canis and H. americanum.

Methods In this study, blood, heart, and/or spleen samples were collected from 278 wild canids (180 coyotes, 93 red foxes, and 5 gray foxes) in the eastern US and tested via PCR for Hepatozoon. Histology slides of heart and skeletal muscle were assessed for Hepatozoon cysts and associated inflammation when fresh tissue was available (n = 96).

Results Hepatozoon spp. were …