Veterinary Medicine Commons^™

Evaluation Of Ankom F58 Filter Bags Compared To Beakers For Analysis Of Neutral Detergent Fiber, Sawyer R. Kappel, Rebecca L. Sjostrand, J. C. Macdonald

Nebraska Beef Cattle Reports

Feed ingredient, feed refusals, duodenal and fecal samples were analyzed to compare two methods of determining neutral detergent fiber. All samples were weighed into Ankom F58 fiber bags and Analyzed using an Ankom 2000 automated fiber Analyzer. Results were then compared to the Van Soest beaker method. The fiber values determined from both methods were within 3.5% of one another, with the beaker method being consistently greater compared to the Ankom method, except for fecal samples. Variability in fiber estimates for ingredients, feed refusals, and feces translated to substantial inconsistency in estimated neutral detergent fiber digestibilities among treatments. It is …

Forage Evaluation Of Crested Wheatgrass, Kelton C. Adair, K. H. Jenkins Pas, Andrea K. Watson, James C. Macdonald

Nebraska Beef Cattle Reports

An experiment evaluated the forage value of crested wheatgrass (CWG) harvested throughout the grazing season near Sidney, Nebraska over a two-year period (2019-2020). The purpose of the evaluation was to determine forage quality and rumen undegradable protein (RUP) content to help producers with supplementation decisions for cattle grazing monoculture CWG pastures. In vitro dry matter disappearance quadratically decreased from 54% in May to 37% in September of 2019, with no changes throughout 2020, averaging 43%. In both years, crude protein (CP) decreased throughout the growing season while rumen undegradable protein (RUP) increased (as % CP). Digestible RUP was less than …

Effects Of Strategic Supplementation On Return To Management And Performance Of Yearling Cattle, Kaylee E. Wheeler, Dean Dustin, Jay Parsons, M. E. Drewnoski, K. H. Jenkins Pas

Nebraska Beef Cattle Reports

A three-year experiment evaluated the effects of two supplementation strategies on yearling cattle performance and producer returns to management. Yearling cattle grazed on crested wheatgrass pastures and were supplemented either throughout the entire grazing season, only during the latter part of the grazing season, or not supplemented at all. The supplemented yearlings received 3.5 lb of dried distillers grains with solubles 6 days/week. On average non-supplemented yearlings had an average daily gain of 1.1 lb/d and providing supplement increased average daily gain by 0.5 lb/d. Yearlings supplemented during the latter part of the season had similar performance to yearlings supplemented …

Timing Of Implant Use In The Backgrounding System, Kelton C. Adair, Kylie M. Butterfield, Zach E. Carlson, Braden C. Troyer, Jiehua Xiong, Mitchell M. Norman, James C. Macdonald, Galen E. Erickson, M. E. Drewnoski, Brandon L. Nuttelman

Nebraska Beef Cattle Reports

A two-year study utilized 240 weaned steers each year in a 3-phase yearling production system: winter backgrounding, summer grazing, and finishing. The objective of the study was to determine the effects of winter rate of gain (LOW or HIGH) and implant strategy during the winter backgrounding and summer grazing periods on compensatory gain, animal performance, and carcass characteristics. Calves received 1 of 3 implant strategies: NONE, SINGLE (Revalor-G during summer grazing), and MULTIPLE (Ralgro during winter backgrounding and Revalor-G during summer grazing). All cattle received a Revalor-XS during the finishing phase. Implant strategy and rate of gain during the winter …

Artificial Insemination Of Beef Heifers With Multi-Sire Sexed Semen, Dempster Christenson, John Maddux, Jordan M. Thomas, R. Funston

Nebraska Beef Cattle Reports

This study observed pregnancy outcomes resulting from artificial insemination of beef heifers with multi-sire sexed semen. It was hypothesized, pregnancy rates resulting from multi-sire sexed semen would be increased compared to pregnancy rates from prior studies using single-sire sexed semen. Producers looking to maximize the proportion of calves of one sex may consider the technique. Ultrasound determined pregnancy rate of heifers given multi-sire sexed semen was 65%, which is 12% greater than the average pregnancy rate reported in previous studies using single-sire sexed semen. After accounting for date of birth however, the adjusted AI conception rate was calculated to range …

Effect Of Increasing Energy 30 Days Prior To Artificial Insemination In Beef Heifers, Landon F. Tadich, Rachel E.S. Rogers, Jim R. Teichert, R. Funston

Nebraska Beef Cattle Reports

A 3-yr study utilized 300 Angus-based, spring-born heifers to evaluate postweaning heifer development systems on gain and reproductive performance. Three groups of heifers were developed over the winter development period either grazing winter range or fed a dry lot diet targeted to 1.5 lb/d of gain in order to achieve 65% of their mature body weight at breeding. Thirty days prior to artificial insemination, heifers grazing winter rand entered the dry lot and were fed this same diet, one group of dry lot heifers remained on this diet, and the other received increased energy in the form of wet corn …

Including Gene Edited Sires In Genetic Evaluations, Leticia P. Sanglard, Garret M. See, Matthew L. Spangler

Nebraska Beef Cattle Reports

A simulation study investigated and provided potential solutions to practical issues that could arise from including gene-edited sires in routine genetic evaluations. Gene-editing is a technique for adding, deleting, or replacing nucleotides in the genome. Editing nucleotides controlling important socioeconomic traits (e.g., growth, carcass, disease susceptibility) is expected to improve rates of genetic gain. However, targeted alterations of the genome can affect the relationship among individuals and, consequently, introduce bias in Expected Progeny Differences. The current study illustrated that, indeed, Expected Progeny Differences for the progeny of edited sires were underestimated. Consequently, these animals would be less likely to be …

Comparison Of Semi-Confined And Pasture-Based August Calving Beef Cow Systems, Hannah F. Speer, Harvey C. Freetly, M. E. Drewnoski

Nebraska Beef Cattle Reports

Limited pasture availability and increased pasture rental rates have generated a need to evaluate alternative cow-calf production systems. The current study compared cow and calf performance in two August-calving cow systems that combined corn residue grazing with 1) perennial forage grazing and hay or 2) summer drylot feeding and fall cover crop grazing. Differences in pregnancy rates between systems within year were not observed; however, the effect of production system on cow body condition and calf body weight at different time points varied across years. Overall, cow and calf performance were not negatively impacted in the drylot/cropland system, suggesting that …

Impact Of Planning Horizon Length On Breeding Objectives And Resulting Selection Decisions, Hunter F. Valasek, Bruce L. Golden, Matthew L. Spangler

Nebraska Beef Cattle Reports

The weighting of traits in a selection index depends on varying circumstances that can difer among beef producers (e.g. economic factors, breeding systems). The determination of planning horizon is an additional variable that can differ among producers that represents the impact of genetic selection decisions over a gradient of time. A web-based economic index construction platform (iGENDEC) was used in the current study to investigate the implications of planning horizon on relative emphasis values of traits within the breeding goal and potential differences in sire selection decisions. General-purpose indexes were created for three breeding systems under six different …

The Use Of A Habitat Quality Stress Index To Evaluate Stress As An Analog For Proximate Fitness In The American Crow Within A Matrix Of Landcover Characteristics To Assess Its Potential Contribution To Disease Etiologies, Theodore Lee Grabarz

Antioch University Dissertations & Theses

All organisms occur within spatial and temporal environments to maximize proximate fitness (health) and thus life history outcomes. Previous work has examined the temporal and behavioral aspects of proximate fitness on life history outcomes particularly regarding highly perturbed environments (i.e., climate and land use change, resource extraction, agricultural erosion, etc.). My work focuses on the less examined spatial aspect of these perturbed environments. More specifically, this dissertation examines habitat selection and quality as the basis for understanding stress response (negative and positive feedback mechanisms) to environmental stressors within the larger context of regional or gamma (ɣ) biodiversity. Through the lens …

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 …

Turkey Vulture Survival Is Reduced In Areas Of Greater Road Density, Adrián Naveda-Rodríguez, Keith L. Bildstein, David R. Barber, Jean-François Therrien, Michael L. Avery, Bryan M. Kluever, Scott A. Rush, Francisco J. Vilella

United States Department of Agriculture Wildlife Services: Staff Publications

The demography of, and factors that influence these metrics, are largely unknown for most vultures in the Americas. Survivorship of turkey vultures (Cathartes aura) may be influenced by landscape heterogeneity and human disturbance. We quantified the effects of landscape composition (Shannon’s diversity index) and configuration (contagion, edge density, and largest patch index), and human disturbance (road density) on the annual and seasonal survival probabilities of the three North American breeding populations (western, central, and eastern) of turkey vultures that spend the nonbreeding season in the southeastern portion of the Nearctic and the northern Neotropics during a 17-year period. …

Echinococcus Species Infections Among Wild Canids In Pennsylvania, Usa, Kayla Garrett, Justin Brown, Ryan K. A. Grunert, Jonathan Hunte, Mark G. Ruder, Kyle Van Why, Michael J. Yabsley, Christopher A. Cleveland

United States Department of Agriculture Wildlife Services: Staff Publications

Echinococcus species are zoonotic tapeworms that can impact the health of wildlife, domestic animals, livestock, and humans. Two species of interest in North America are Echinococcus multilocularis and Echinococcus canadensis (Echinococcus granulosus sensu lato). The primary wildlife definitive hosts for E. multilocularis and E. canadensis are similar, including red foxes (Vulpes vulpes), gray foxes (Urocyon cinereoargenteus), coyotes (Canis latrans), and wolves (Canis lupus). These two Echinococcus spp. use different intermediate hosts, including small mammals for E. multilocularis and artiodactylids for E. canadensis. Although historically absent from …

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 …

A Next-Generation Sequencing Study Of Arthropods In The Diet Of Laysan Teal Anas Laysanensis, Wieteke A. Hothuijzen, Carmen C. Antaky, Elizabeth N. Flint, Jonathan H. Plissner, Coral A. Wolf, Holly P. Jones

United States Department of Agriculture Wildlife Services: Staff Publications

The critically endangered Laysan teal Anas laysanensis (known as koloa po¯haka in the Hawaiian language), in the northwestern Hawaiian Islands has wild populations on Kamole (Laysan Island), Kuaihelani (Midway Atoll NWR) and Ho¯laniku¯ (Kure Atoll). The Laysan teal face a new risk on Sand Island in Kuaihelani: non-target poisoning via a pending House Mouse Mus musculus eradication program. After mice were observed attacking and depredating Laysan albatross Phoebastria immutabilis (mo¯lı¯) in 2015, plans to eradicate the mice were developed to protect this seabird species. This approach, however, risks poisoning the Laysan teal. To reduce exposure, teal will be translocated during …

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 …

Movements And Resource Selection Of Wild Pigs Associated With Growth Stages Of Corn, Bethany A. Friesenhahn, Randall W. Deyoung, Michael J. Cherry, Humberto L. Perotto-Baldivieso, Kurt C. Vercauteren, Nathan P. Snow

United States Department of Agriculture Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) are one of the most successful invasive species globally and are often implicated in agricultural damage. This damage is expected to increase as ranges of wild pigs expand, impacting the human food supply and increasing costs of food production. Our objective was to evaluate movement behaviors of wild pigs relative to resource availability and landscape features in an agriculture-dominated landscape, with a goal of informing management practices for reducing damage to corn. We monitored hourly movements of adult wild pigs relative to corn crops using GPS collars during the 2019 and 2020 growing seasons (Feb–Sept) in …

Burmese Pythons In Florida: A Synthesis Of Biology, Impacts, And Management Tools, Jacquelyn C. Guzy, Bryan G. Falk, Brian J. Smith, John David Willson, Robert N. Reed, Nicholas G. Aumen, Michael L. Avery, Ian A. Bartoszek, Earl Campbell, Michael S. Cherkiss, Natalie M. Claunch, Andrea F. Currylow, Tylan Dean, Jeremy Dixon, Richard Engeman, Sarah Funck, Rebekah Gibble, Kodiak C. Hengstebeck, John S. Humphrey, Margaret E. Hunter, Jillian M. Josimovich, Jennifer Ketterlin, Michael Kirkland, Frank J. Mazzotti, Robert Mccleery, Melissa A. Miller, Matthew Mccollister, M. Rockwell Parker, Shannon E. Pittman, Michael Rochford, Christina Romagosa, Art Roybal, Ray W. Snow, Mckayla M. Spencer, J. Hardin Waddle, Any A. Yackel Adams, Kristen M. Hart

United States Department of Agriculture Wildlife Services: Staff Publications

Burmese pythons (Python molurus bivittatus) are native to southeastern Asia, however, there is an established invasive population inhabiting much of southern Florida throughout the Greater Everglades Ecosystem. Pythons have severely impacted native species and ecosystems in Florida and represent one of the most intractable invasive-species management issues across the globe. The difficulty stems from a unique combination of inaccessible habitat and the cryptic and resilient nature of pythons that thrive in the subtropical environment of southern Florida, rendering them extremely challenging to detect. Here we provide a comprehensive review and synthesis of the science relevant to managing invasive …

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 …

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 …

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 …

Demographic And Functional Responses Of Kit Foxes To Changes In Prey Abundance, Ashley E. Hodge, Eric M. Gese, Bryan M. Kluever

United States Department of Agriculture Wildlife Services: Staff Publications

Many carnivores exhibit demographic and functional responses to changes in prey abundance. Demographic responses often include changes in population size, litter size, and recruitment of young into the adult population. Functional feeding responses are commonly reported for many carnivore species. We investigated demographic and functional responses of kit foxes (Vulpes macrotis Merriam, 1888) to changes in prey abundance during 2010–2013 in western Utah, USA. Between 2010 and 2013, litter size averaged 3.9 (±1.4) pups/litter. Survival rates of kit fox pups were 0.07, 0.01, 0.46, and 0.16, respectively, and there was a correlation between pup survival rates and rodent abundance; …

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 …

Defining County-Level Terrestrial Rabies Freedom Using The Us National Rabies Surveillance System: Surveillance Data Analysis, Amber Kunkel, Gabriella Veytsel, Sarah C. Bonaparte, Haillie Meek, Xiaoyue Ma, Amy J. Davis, Jesse Bonwitt, Ryan M. Wallace

United States Department of Agriculture Wildlife Services: Staff Publications

Background: Rabies is a deadly zoonotic disease with nearly 100% fatality rate. In the United States, rabies virus persists in wildlife reservoirs, with occasional spillover into humans and domestic animals. The distribution of reservoir hosts in US counties plays an important role in public health decision-making, including the recommendation of lifesaving postexposure prophylaxis upon suspected rabies exposures. Furthermore, in surveillance data, it is difficult to discern whether counties have no cases reported because rabies was not present or because counties have an unreported rabies presence. These epizootics are monitored by the National Rabies Surveillance System (NRSS), to which approximately 130 …

Comparison Of An Antioxidant Source And Antioxidant Plus Bcaa On Athletic Performance And Post Exercise Recovery Of Horses, Emily Kent, Stephen J. Coloman, Jason E. Bruemmer, Renan Regatieri Casagrande, Christine Levihn, Grace Romo, Kevin Herkelman, Tanja Hess

United States Department of Agriculture Wildlife Services: Staff Publications

Antioxidant supplementation decreases postexercise oxidative stress but could also decrease muscle pro- tein synthesis. This study compared the effects of three diets: low antioxidant (control, CON), high an- tioxidant (AO), and branched-chain amino acid high antioxidant (BCAO) supplementation on postexercise protein synthesis and oxidative stress. We hypothesized that supplementing antioxidants with branched- chain amino acids(BCAA) would reduce oxidative stress without hindering muscle protein synthesis. Eigh- teen mixed-breed polo horses (11 mares and 7 geldings, with age range between 5 and 18 years, were on CON diet for 30 days (from day -45 until day 0) and then were assigned to …

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 …

Behavior Of Wild Pigs Toward Conspecific Carcasses: Implications For Disease Transmission In A Hot, Semiarid Climate, Samantha Leivers, Tyler Campbell, Michael J. Bodenchuk, John Tomeĉek

United States Department of Agriculture Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) are a prolific, invasive species in the United States of America and act as vectors for many pathogens. An emerging pathogen of concern to the USA is African swine fever (ASF), a deadly viral disease affecting swine that is endemic to Africa and has spread to parts of Europe, Asia, and the Caribbean. ASF affects both wild and domesticated pigs and can be transmitted via several avenues, including interactions between and consumption of dead pigs by their live conspecifics. As wild pigs are considered a serious threat in the transmission of ASF, understanding the …

Deriving Spatially Explicit Direct And Indirect Interaction Networks From Animal Movement Data, Anni Yang, Mark Q. Wilber, Kezia R. Manlove, Ryan S. Miller, Raoul Boughton, James Beasley, Joseph Northrup, Kurt C. Vercauteren, George Wittemyer, Kim Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Quantifying spatiotemporally explicit interactions within animal populations facilitates the understanding of social structure and its relationship with ecological processes. Data from animal tracking technologies (Global Positioning Systems [“GPS”]) can circumvent longstanding challenges in the estimation of spatiotemporally explicit interactions, but the discrete nature and coarse temporal resolution of data mean that ephemeral interactions that occur between consecutive GPS locations go undetected. Here, we developed a method to quantify individual and spatial patterns of interaction using continuous-time movement models (CTMMs) fit to GPS tracking data. We first applied CTMMs to infer the full movement trajectories at an arbitrarily fine temporal scale …