Veterinary Infectious Diseases Commons^™

Raccoon Densities Across Four Land Cover Types In The Southeastern United States, Jocab E. Hill, James L. Helton, David A. Bernasconi, Wesley C. Dixon, Matt T. Hamilton, Richard B. Chipman, Amy T. Gilbert, James C. Beasley, Guha Dharmarajan, Olin E. Rhodes Jr.

United States Department of Agriculture Wildlife Services: Staff Publications

Raccoons (Procyon lotor) are the primary reservoir for rabies virus in eastern North America. Management of rabies in raccoons is achieved primarily with the use of oral rabies vaccination (ORV) and effective ORV bait densities are determined in part by the densities of raccoons. Decisions regarding ORV bait densities, however, are limited by an incomplete understanding of raccoon densities across the spectrum of landscapes they occupy. We carried out a markrecapture study of raccoons on the Savannah River Site in South Carolina, USA, from 2017–2019, to develop sex‐ and landscape‐specific raccoon density estimates across 4 rural land cover …

Understory Arthropod Diversity In A Mixed Dryland Ecosystem, Hawai‘I, Matthew J. Madeiros, William P. Haines, Clare E. Aslan, Aaron B. Shiels, Asa Aue, Christina T. Liang

United States Department of Agriculture Wildlife Services: Staff Publications

Tropical drylands are among the most threatened ecosystems worldwide, and fewer than 10% of tropical dry forests in Hawai‘i remain intact. Terrestrial arthropods comprise most of the endemic fauna on many islands, including Hawai‘i, where they provide ecosystem services such as pollination, decomposition, and a reliable prey base for predators. The objective of our study was to measure understory arthropod diversity and relative abundances in two common habitat types within dryland Hawai‘i—a non-native grassland, dominated by Cenchrus setaceus (fountain grass) with few native shrubs, and a native woodland, dominated by Metrosideros polymorpha (‘ōhi‘a). We used generalized additive models to examine …

Range-Wide Sources Of Variation In Reproductive Rates Of Northern Spotted Owls, Jeremy T. Rockweit, Julianna M. Jenkins, James E. Hines, James D. Nichols, Katie M. Dugger, Alan B. Franklin, Peter C. Carlson, William L. Kendall, Damon B. Lesmeister, Christopher Mccafferty, Steven H. Ackers, L. Steven Andrews, Larissa L. Bailey, Jesse Burgher, Kenneth P. Burnham, Tara Chestnut, Mary M. Conner, Raymond J. Davis, Krista E. Dilione, Eric D. Forsman, Elizabeth M. Glenn, Scott A. Gremel, Keith A. Hamm, Dale R. Herter, J. Mark Higley, Rob B. Horn, David W. Lamphear, Trent L. Mcdonald, Janice A. Reid, Carl J. Schwarz, David C. Simon, Stan G. Sovern, James K. Swingle, J. David Wiens, Heather Wise, Charles B. Yackulic

United States Department of Agriculture Wildlife Services: Staff Publications

We conducted a range-wide investigation of the dynamics of site-level reproductive rate of northern spotted owls using survey data from 11 study areas across the subspecies geographic range collected during 1993–2018. Our analytical approach accounted for imperfect detection of owl pairs and misclassification of successful reproduction (i.e., at least one young fledged) and contributed further insights into northern spotted owl population ecology and dynamics. Both nondetection and state misclassification were important, especially because factors affecting these sources of error also affected focal ecological parameters. Annual probabilities of site occupancy were greatest at sites with successful reproduction in the previous year …

Evaluation Of Roost Culling As A Management Strategy For Reducing Invasive Rose‑Ringed Parakeet (Psittacula Krameri) Populations, C. Janes Anderson, Leonard A. Brennan, William P. Bukoski, Steven C. Hess, Clayton D. Hilton, Aaron B. Shiels, Shane Siers, Bryan M. Kluever, Page E. Klug

United States Department of Agriculture Wildlife Services: Staff Publications

Rose-ringed parakeets (Psittacula krameri) are one of the most widespread invasive avian species worldwide. This species was introduced to the island of Kaua‘i, Hawai‘i, USA, in the 1960s. The rapidly increasing population has caused substantial economic losses in the agricultural and tourism industries. We evaluated the efficacy of a roost culling program conducted by an independent contractor from March 2020 to March 2021. We estimated island-wide minimum abundance was 10,512 parakeets in January 2020 and 7,372 in April 2021. Over 30 nights of culling at four roost sites, approximately 6,030 parakeets were removed via air rifles with 4,415 …

Social Network Analysis Of White-Tailed Deer Scraping Behavior: Implications For Disease Transmission, Michael E. Egan, Kim M. Pepin, Justin Fischer, Scott R. Hygnstrom, Kurt C. Vercauteren, Guillaume Bastille-Rousseau

United States Department of Agriculture Wildlife Services: Staff Publications

Host contact structure affects pathogen transmission in host populations, but many measures of host contact do not distinguish contacts that are relevant to pathogen transmission from those that are not. Scrapes are sites for chemical communication by white-tailed deer (Odocoileus virginianus) during the breeding season and potential sites of transmission of prions, the causative agent of chronic wasting disease (CWD). Scrape-related behaviors vary in their probability of transmitting prions to or from the environment, suggesting that behavior be combined with contact structure to better reflect potential heterogeneity in prion transmission at scrapes. We recorded visits and behaviors by …

High Winds And Melting Sea Ice Trigger Landward Movement In A Polar Bear Population Of Concern, Annie Kellner, Todd C. Atwood, David C. Douglas, Stewart W. Breck, Colorado State University - Fort Collins

United States Department of Agriculture Wildlife Services: Staff Publications

Some animal species are responding to climate change by altering the timing of events like mating and migration. Such behavioral plasticity can be adaptive, but it is not always. Polar bears (Ursus maritimus) from the southern Beaufort Sea subpopulation have mostly remained on ice year-round, but as the climate warms and summer sea ice declines, a growing proportion of the subpopulation is summering ashore. The triggers of this novel behavior are not well understood. Our study uses a parametric time-to-event model to test whether biological and/or time-varying environmental variables thought to influence polar bear movement and habitat selection …

Space Use And Movements Of Southeastern Breeding Double-Crested Cormorants (Nannopterum Auritum) In The United States, Leah L.K. Moran, Brian S. Dorr, Katie C. Hanson-Dorr, R. J. Moore, Scott A. Rush

United States Department of Agriculture Wildlife Services: Staff Publications

Abstract: Seasonal movements of Double-crested Cormorants (Nannopterum auritum) have been studied at breeding and wintering sites in the southeastern United States, but little information exists on the movements of these birds within and from their southern breeding sites in lacustrine systems. Since 2001, cormorants have established nesting colonies on islands in Guntersville Reservoir in Alabama, USA. Following the movements of tagged cormorants using satellite telemetry, we found that the mean home range during the 2017 breeding season (May–August) was 41.76 km², with a core use area of 6.36 km². The mean home range used …

Disease Progression And Serological Assay Performance In Heritage Breed Pigs Following Brucella Suis Experimental Challenge As A Model For Naturally Infected Feral Swine, Vienna R. Brown, Ryan S. Miller, Courtney F. Bowden, Timothy J. Smyser, Nicholas A. Ledesma, Aim E. Hartwig, Paul Gordy, Aaron M. Anderson, Stephanie M. Porter, Kate Alexander, Zane Gouker, Tom Gidlewski, Richard A. Bowen, Angela M. Bosco-Lauth

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive feral swine (Sus scrofa) are one of the most important wildlife species for disease surveillance in the United States, serving as a reservoir for various diseases of concern for the health of humans and domestic animals. Brucella suis, the causative agent of swine brucellosis, is one such pathogen carried and transmitted by feral swine. Serology assays are the preferred field diagnostic for B. suis infection, as whole blood can be readily collected and antibodies are highly stable. However, serological assays frequently have lower sensitivity and specificity, and few studies have validated serological assays for B. suis in feral swine. …

Evaluation Of The Effect Of Hydrated Lime On The Scavenging Of Feral Swine (Sus Scrofa) Carcasses And Implications For Managing Carcass-Based Transmission Of African Swine Fever Virus, Courtney F. Bowden, James Grinolds, Gregory Franckowiak, Loma Mccallister, Joe M. Halseth, Matthew Cleland, Travis Guerrant, Michael J. Bodenchuk, Robert Miknis, Michael C. Marlow, Vienna R. Brown

United States Department of Agriculture Wildlife Services: Staff Publications

African swine fever (ASF) is a devastating hemorrhagic disease marked by extensive morbidity and mortality in infected swine. The recent global movement of African swine fever virus (ASFV) in domestic and wild swine (Sus scrofa) populations has initiated preparedness and response planning activities within many ASF-free countries. Within the US, feral swine are of utmost concern because they are susceptible to infection, are wide-spread, and are known to interact with domestic swine populations. African swine fever virus is particularly hardy and can remain viable in contaminated carcasses for weeks to months; therefore, carcass-based transmission plays an important role in the …

H7n9 Influenza A Virus Transmission In A Multispecies Barnyard Model, Angela M. Bosco-Lauth, Anna Rodriguez, Rachel M. Maison, Stephanie M. Porter, J. Jeffrey Root

United States Department of Agriculture Wildlife Services: Staff Publications

Influenza A viruses are a diverse group of pathogens that have been responsible for millions of human and avian deaths throughout history. Here, we illustrate the transmission potential of H7N9 influenza A virus between Coturnix quail (Coturnix sp.), domestic ducks (Anas platyrhynchos domesticus), chickens (Gallus gallus domesticus), and house sparrows (Passer domesticus) co-housed in an artificial barnyard setting. In each of four replicates, individuals from a single species were infected with the virus. Quail shed virus orally and were a source of infection for both chickens and ducks. Infected chickens transmitted the virus to quail but not to ducks or …

Writing Statistical Methods For Ecologists, Amy J. Davis, Shannon Kay

United States Department of Agriculture Wildlife Services: Staff Publications

The Methods section is a key component of any ecology research publication containing detailed information on how the data were collected and analyzed. However, descriptions of which statistical methods were used and how they were applied can substantially vary and may not provide enough information for the analyses to be reproducible. Computational and statistical programming advances have allowed ecological researchers without a strong statistical or mathematical background to access and use increasingly complex statistical methods. Thus, statistical methods are written by and need to be accessible to researchers across a range of quantitative expertise. Poorly written Methods sections can incorrectly …

Variance In Offspring Sex Ratio And Maternal Allocation In A Highly Invasive Mammal, Sarah M. Chinn, Timothy J. Smyser, James C. Beasley

United States Department of Agriculture Wildlife Services: Staff Publications

Skewed sex ratios at birth are widely reported in wild populations, however, the extent to which parents are able to modulate the sex ratio of offspring to maximize their own fitness remains unclear. This is particularly true for highly polytocous species as maximizing fitness may include trade-offs between sex ratio and the size and number of offspring in litters. In such cases, it may be adaptive for mothers to adjust both the number of offspring per litter and offspring sex to maximize individual fitness. Investigating maternal sex allocation in wild pigs (Sus scrofa) under stochastic environmental conditions, we predicted that …

Perturbations Highlight Importance Of Social History In Parakeet Rank Dynamics, Annemarie Van Der Marel, Xavier Francis, Claire L. O'Connell, Cesar O. Estien, Chelsea Carminito, Virginia Darby Moore, Nickolas Lormand, Bryan M. Kluever, Elizabeth A. Hobson

United States Department of Agriculture Wildlife Services: Staff Publications

Dominance hierarchies can provide many benefits to individuals, such as access to resources or mates, depending on their ranks. In some species, rank can emerge as a product of a group’s history of social interactions. However, it can be difficult to determine whether social history is critical to rank in observation-based studies. Here, we investigated rank dynamics in three captive groups of monk parakeets (Myiopsitta monachus). We used experimental social perturbations to test whether social history shapes rank emergence in these groups. Using targeted removals and reintroductions, we tested whether differently ranked individuals could re-take their ranks in hierarchies after …

Distribution Of The Misfolded Isoform Of The Prion Protein In Peripheral Tissues And Spinal Cord Of Rocky Mountain Elk (Cervus Elaphus Nelsoni) With Naturally Occurring Chronic Wasting Disease, Terry R. Spraker, Thomas Gidlewski, J. G. Powers, T. A. Nichols, M. A. Wild

United States Department of Agriculture Wildlife Services: Staff Publications

Chronic wasting disease (CWD) is an infectious transmissible spongiform encephalopathy of cervids associated with the presence of a misfolded prion protein (PrPCWD). Progression of PrPCWD distribution has been described using immunohistochemistry and histologic changes in a single section of brain stem at the level of the obex resulting in scores from 0 (early) to 10 (terminal) in elk with naturally occurring CWD. Here we describe the spread and distribution of PrPCWD in peripheral tissues and spinal cord in 16 wild and 17 farmed Rocky Mountain elk (Cervus elaphus nelsoni) with naturally occurring CWD and correlate these findings with obex scores. …

Predator Telemetry Informs Temporal And Spatial Overlap With Stocked Salmonids In Lake Huron, David G. Fielder, Todd A. Hayden, Thomas R. Binder, Brian S. Dorr, Heidi A. Currier

United States Department of Agriculture Wildlife Services: Staff Publications

Double-Crested Cormorants (Phalacrocorax auratus), Walleyes (Sander vitreus), and Lake Trout (Salvelinus namaycush) are migratory predators that undergo extensive movements in Lake Huron. Stocking of juvenile salmonid fish (Oncorhynchus and Salmo sp.) is an important component of fishery management in Lake Huron and assessing the spatial and temporal extent of predator movements is a useful consideration for determining when and where to stock juvenile fish to reduce predation and maximize survival. Previous investigation indicated that some Walleyes migrate to the main basin of Lake Huron in spring from Saginaw Bay. Similarly, telemetry studies of Lake Trout movement in Lake Huron have …

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. …

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 …

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. …

Role Of Social Structure In Establishment Of An Invasive Large Mammal After Translocation, Lindsay M. Clontz, Anni Yang, Sarah M. Chinn, Kim M. Pepin, Kurt C. Vercauterten, George Wittemyer, Ryan S. Miller, James C. Beasley

United States Department of Agriculture Wildlife Services: Staff Publications

Background

Data on the movement behavior of translocated wild pigs is needed to develop appropriate response strategies for containing and eliminating new source populations following translocation events. We conducted experimental trials to compare the home range establishment and space-use metrics, including the number of days and distance traveled before becoming range residents, for wild pigs translocated with their social group and individually.

Results

We found wild pigs translocated with their social group made less extensive movements away from the release location and established a stable home range ~5 days faster than those translocated individually. We also examined how habitat quality …

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 …

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 …

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 …

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 …

Interspecific Oral Rabies Vaccine Bait Competition In The Southeast United States, Wesley C. Dixon, Jacob E. Hill, Richard Chipman, Amy J. Davis, Amy Gilbert, James C. Beasley, Olin E. Rhodes Jr., Guha Dharmarajan

United States Department of Agriculture Wildlife Services: Staff Publications

The United States Department of Agriculture’s National Rabies Management Program (NRMP) has coordinated the use of oral rabies vaccination (ORV) to control the spread of raccoon rabies virus variant west of the Appalachian Mountains since 1997. Working with state and local partners, the NRMP deploys ORV baits containing a rabies vaccine, primarily targeting raccoon populations (Procyon lotor). Bait competition between raccoons and non-target species may limit the effectiveness of ORV programs, but the extent of bait competition remains poorly quantified, particularly in the southeastern United States. We placed placebo ORV baits in bottomland hardwood (n = 637 baits) and upland …

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 …

Evaluation Of Oral Baits And Distribution Methods For Tasmanian Devils (Sarcophilus Harrisii), Sean Dempsey, Ruth J. Pyer, Amy Gilbert, Nicholas M. Fountain-Jones, Jennifer M. Moffat, Sarah Benson-Amram, Timothy J. Smyser, Andrew S. Flies

United States Department of Agriculture Wildlife Services: Staff Publications

Context

Diseases are increasingly contributing to wildlife population declines. Tasmanian devil (Sarcophilus harrisii) populations have locally declined by 82%, largely owing to the morbidity and mortality associated with two independent transmissible devil facial tumours (DFT1 and DFT2). Toxic baits are often used as a management tool for controlling vertebrate pest populations in Australia, but in other areas of the world, oral baits are also used to deliver vaccines or pharmaceuticals to wildlife.

Aim

Our goal was to evaluate the potential use of edible baits as vehicles for vaccine delivery to Tasmanian devils.

Method

We first tested bait palatability with …

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 …