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

Pathology Of Chronic Mycoplasma Ovipneumoniae Carriers In A Declining Bighorn Sheep (Ovis Canadensis) Population, Jennifer L. Malmberg, Samantha E. Allen, Jessica E. Jennings-Gaines, Marguerite Johnson, Katie L. Luukkonen, Kara M. Robbins, Todd E. Cornish, Rachel A. Smiley, Brittany L. Wagler, Zach Gregory, Daryl Lutz, Pat Hnlicka, Kevin L. Monteith, William H. Edwards

United States Department of Agriculture Wildlife Services: Staff Publications

Bighorn sheep (Ovis canadensis) across North America commonly experience populationlimiting epizootics of respiratory disease. Although many cases of bighorn sheep pneumonia are polymicrobial, Mycoplasma ovipneumoniae is most frequently associated with all-age mortality events followed by years of low recruitment. Chronic carriage of M. ovipneumoniae by adult females serves as a source of exposure of naïve juveniles; relatively few ewes may be responsible for maintenance of infection within a herd. Test-and-remove strategies focused on removal of adult females with evidence of persistent or intermittent shedding (hereafter chronic carriers) may reduce prevalence and mitigate mortality. Postmortem confirmation of pneumonia …

Molecular Characterization Of Non-H5 And Non-H7 Avian Influenza Viruses From Non-Mallard Migratory Waterbirds Of The North American Flyways, 2006–2011, Shahan Azeem, John A. Baroch, Deepanker Tewari, Kristy L. Pabilonia, Mary L. Killian, Birgit Bradel-Tretheway, Dong Sun, Sara Ghorbani-Nezami, Kyoung-Jin Yoon

United States Department of Agriculture Wildlife Services: Staff Publications

The surveillance of migratory waterbirds (MWs) for avian influenza virus (AIV) is indispensable for the early detection of a potential AIV incursion into poultry. Surveying AIV infections and virus subtypes in understudied MW species could elucidate their role in AIV ecology. Oropharyngeal–cloacal (OPC) swabs were collected from non-mallard MWs between 2006 and 2011. OPC swabs (n = 1,158) that molecularly tested positive for AIV (Cts ≤ 32) but tested negative for H5 and H7 subtypes were selected for virus isolation (VI). The selected samples evenly represented birds from all four North American flyways (Pacific, Central, Mississippi, and Atlantic). Eighty-seven …

Home Range And Resource Selection Of Virginia Opossums In The Rural Southeastern United States, Jacob E. Hill, David A. Bernasconi, Richard B. Chipman, Amy T. Gilbert, James C. Beasley, Olin E. Rhodes Jr., Guha Dharmarajan

United States Department of Agriculture Wildlife Services: Staff Publications

The Virginia opossum (Didelphis virginiana) has a rapidly expanding distribution in North America, but many aspects of its ecology remain relatively understudied, particularly in rural areas of its core range. We collected GPS telemetry data from 93 opossums in a rural, non-agricultural landscape in South Carolina, USA (2018–2019) to examine factors influencing space use and resource selection. Estimated male home ranges (99% utilization distributions) were on average 50% larger than those of females (mean home range 115.9 ± 103.7 ha vs 76.7 ± 75.0 ha). The home range size decreased on average by 20% with each 20% increase …

Expanding Cwd Disease Surveillance Options Using Environmental Contamination At Deer Signposts, Miranda Hsiang-Ning Jacobson Huang

United States Department of Agriculture Wildlife Services: Staff Publications

1. Environmental surveillance can allow early detection of diseases, which increases management options and can improve disease trajectories. Chronic wasting disease (CWD) in cervids is a significant prion disease that has been spreading across North America since the 1960s, leading to cervid population declines and concern from hunters and state wildlife agencies. White-tailed deer have a unique breeding season behavior called scraping, where they deposit urine and saliva at shared sites. Since both these fluids can contain CWD prions, scrape sites have the potential to serve as sentinel sites for environmental surveillance of CWD.

2. To examine this potential, we …

Taphonomic Signatures Of Early Scavenging By Black And Turkey Vultures, Marian L. Wahl, Grant N. Burcham, Amanda M. Herbert, Lee A. Humberg, Patrick A. Zollner, Landon R. Jones, Brandon M. Quinby, Bryan M. Kluever

United States Department of Agriculture Wildlife Services: Staff Publications

Scavenging is critical for nutrient cycling and maintenance of healthy ecosystems. While there is substantial research into the identification of taphonomic signatures from facultative mammalian scavengers, early stage scavenging signatures by vultures remain unknown. Further, some vulture species are opportunistic predators, highlighting the need to define signatures observed in the course of normal scavenging behavior. We placed stillborn neonatal calves in an unoccupied pasture and used motion-trigger camera traps to quantify scavenging effort, then conducted necropsies to evaluate the effect of black vulture (Coragyps atratus) and turkey vulture (Cathartes aura) scavenging effort on carcass consumption. We …

Relief Displacement Of Airborne Objects, Esteban Fernández-Juricic, Joe Crumpton, Morgan B. Pfeiffer, Sathishkummar Saiappan, Jared A. Elmore, Landon R. Jones, B. Santhana Krishnan, Raymond B. Iglay, Bradley F. Blackwell

United States Department of Agriculture Wildlife Services: Staff Publications

The increasing availability of unoccupied aircraft systems (UAS, also referred to as drones) has led to their use in taking vertical aerial photographs at relatively small spatial scales. These photographs can be used to measure the distances between objects appearing in the photographs. However, relief displacement can cause an object above or below ground level to appear at a point in a vertical aerial photograph that is not directly in-line with the object’s actual location, causing a measurement error. A UAS was used in this study as a photographed airborne object because its location and altitude could be controlled. We …

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 …

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 …

Genomic Characterization Of Highly Pathogenic H5 Avian Influenza Viruses From Alaska During 2022 Provides Evidence For Genotype-Specific Trends Of Spatiotemporal And Interspecies Dissemination, Christina A. Ahlstrom, Mia Kim Torchetti, Julianna Lenoch, Kimberlee Beckmen, Megan Boldenow, Evan J. Buck, Bryan Daniels, Krista Dilione, Robert Gerlach, Kristina Lantz, Angela Matz, Rebecca L. Poulson, Laura C. Scott, Gay Sheffield, David Sinnett, David E. Stallknecht, Raphaela Stimmelmayr, Eric Taylor, Alison R. Williams, Andrew M. Ramey

United States Department of Agriculture Wildlife Services: Staff Publications

The ongoing panzootic of highly pathogenic H5 clade 2.3.4.4b avian influenza (HPAI) spread to North America in late 2021, with detections of HPAI viruses in Alaska beginning in April 2022. HPAI viruses have since spread across the state, affecting many species of wild birds as well as domestic poultry and wild mammals. To better understand the dissemination of HPAI viruses spatiotemporally and among hosts in Alaska and adjacent regions, we compared the genomes of 177 confirmed HPAI viruses detected in Alaska during April–December 2022. Results suggest multiple viral introductions into Alaska between November 2021 and August or September 2022, as …

Wildlife Monitoring With Drones: A Survey Of End Users, Raymond B. Iglay, Landon R. Jones, Jared E. Elmore, Kristine O. Evans, Sathish Samiappan, Morgan B. Pfeiffer, Brad F. Blackwell

United States Department of Agriculture Wildlife Services: Staff Publications

Rapid advancements in technology often yield research inquiry into novel applications and drone (i.e., unoccupied aircraft systems or UAS) applications in wildlife management are no exception. We questioned the time lag between drone‐related research and end‐user assessments. We implemented an online, cross‐sectional survey of wildlife professionals to better understand current drone use and benefits or concerns, complemented by a review of contemporary peer‐reviewed and gray literature. We found little disparity between scientific inquiry and end‐user experiences (i.e., similar trends among concerns in published literature and survey results). Exploring new (i.e., advancements in computer vision) and refining original drone applications (i.e., …

Comparing Efficiencies Of Population Control Methods For Responding To Introductions Of Transboundary Animal Diseases In Wild Pigs, Nathan P. Snow, Benjamin Smith, Michael J. Lavelle, Michael P. Glow, Kayleigh Chalkowski, Bruce R. Leland, Sarah Sherburne, Justin W. Fischer, Keely J. Kohen, Seth M. Cook, Hatton Smith, Kurt C. Vercauteren, Ryan S. Miller, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Introductions of transboundary animal diseases (TADs) into free-ranging wildlife can be difficult to control and devastating for domestic livestock trade. Combating a new TAD introduction in wildlife with an emergency response requires quickly limiting spread of the disease by intensely removing wild animals within a contiguous area. In the case of African swine fever virus (ASFv) in wild pigs (Sus scrofa), which has been spreading in many regions of the world, there is little information on the time- and cost-efficiency of methods for intensively and consistently culling wild pigs and recovering carcasses in an emergency response scenario. We compared the …

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 …

Susceptibilities And Viral Shedding Of Peridomestic Wildlife Infected With Clade 2.3.4.4b Highly Pathogenic Avian Influenza Virus (H5n1), J. Jeffrey Root, Stephanie M. Porter, Julianna B. Lenoch, Jeremy W. Ellis, Angela M. Bosco-Lauth

United States Department of Agriculture Wildlife Services: Staff Publications

We tested the ability of six peridomestic wildlife species to replicate a highly pathogenic (HP) clade 2.3.4.4b AIV (H5N1) isolated in the United States during 2022. All tested species replicated and shed virus, at least to some degree. Of the six species evaluated (house sparrows (Passer domesticus), European starlings (Sturnus vulgaris), feral pigeons (Columba livia), striped skunks (Mephitis mephitis), Virginia opossums (Didelphis virginiana), and cottontails (Sylvilagus sp.)), striped skunks and Virginia opossums shed the highest viral titers of 106.3 PFU/mL and 105.0 PFU/mL, respectively. Overall, the results of this …

Chronic Wasting Disease Effects On A Breeding Season Behavior In White-Tailed Deer (Odocoileus Virginianus), Miranda Hsiang-Ning Jacobson Huang, Stephen Demarais, Bronson K. Strickland, Allan Houston, Alejandro Banda, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife disease outbreaks can lead to population declines, which are usually attributed to increased direct or indirect mortality. Alternatively, behavior associated with sickness can lead to social isolation, potentially decreasing fitness of affected individuals. A useful case study to examine this dynamic is chronic wasting disease (CWD), a neurological disease of cervids, known to affect behavior and movement. In this study, we monitored scraping, a White-tailed Deer (Odocoileus virginianus; WTD) breeding season behavior, in an area of high CWD prevalence to determine if this reproductive behavior is affected by CWD. At 107 scrape sites, we detected 3,063 scrape interactions and …

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 …

The Texas Feral Swine Eradication And Control Pilot Program, David R. Pipkin, Bruce R. Leland, Katherine Garwood, Linda Tschirhart-Hejl, Michael J. Bodenchuk, John M. Tomecek

United States Department of Agriculture Wildlife Services: Staff Publications

The United States Agriculture Improvement Act of 2018 (the 2018 Farm Bill) established the Feral Swine Eradication and Control Pilot Program. The program funded US$75M for 5 years, split evenly between the Natural Resources Conservation Service (NRCS) and the Animal and Plant Health Inspection Service (APHIS), both programs within the United States Department of Agriculture. The agencies solicited joint programs from states with high densities of feral swine in two phases. In Texas, NRCS and APHIS submitted three multi-county project areas along watersheds for Phase I funding and one eradication effort along with two crop protection projects in Phase II. …

Spatiotemporal Partitioning Of Two Invasive Ungulates In Guam [Abstract], Kelly J. Koriakin, Kurt C. Vercauteren, Nathan P. Snow, D. Buck Jolley

United States Department of Agriculture Wildlife Services: Staff Publications

Interspecific interactions are crucial in shaping ecosystem dynamics (Connell 1983, Tilman 1987, Barbosa and Castellanos 2005). Non-native ungulates have been introduced across the globe (Ferretti and Lovari 2014, Volery et al. 2021) and in environments where multiple invasives thrive, these co-occurring sympatric species may shift spatiotemporal patterns to minimize interspecific competition (Schoener 1974, Chesson 2000). Spatiotemporal shifts can lead to cascading effects to the native flora and fauna (Simberloff and Von Holle 1999). Given the potential negative impacts, understanding these interactions is vital for effective management of these ecosystems.

Two invasive ungulates, the wild pig (Sus scrofa) and …

The Influence Of Social And Spatial Processes On The Epidemiology Of Environmentally Transmitted Pathogens In Wildlife: Implications For Management, Aakash Pandey, Chris Wojan, Abigail Feuka, Meggan E. Craft, Kezia Manlove, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Social and spatial structures of host populations play important roles in pathogen transmission. For environmentally transmitted pathogens, the host space use interacts with both the host social structure and the pathogen’s environmental persistence (which determines the timelag across which two hosts can transmit). Together, these factors shape the epidemiological dynamics of environmentally transmitted pathogens. While the importance of both social and spatial structures and environmental pathogen persistence has long been recognized in epidemiology, they are often considered separately. A better understanding of how these factors interact to determine disease dynamics is required for developing robust surveillance and management strategies. Here, …