Other Veterinary Medicine Commons^™

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 …

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 …

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 …

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; …

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 …

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 …

Genomic Analyses Of Gray Fox Lineages Suggest Ancient Divergence And Secondary Contact In The Southern Great Plains, Elizabeth M. Kierepka, Sophie Preckler-Quisquater, Dawn M. Reding, Antoinette Piaggio, Seth P.D. Riley, Benjamin N. Sacks

United States Department of Agriculture Wildlife Services: Staff Publications

The gray fox (Urocyon cinereoargenteus) lineage diverged from all other extant canids at their most basal node and is restricted to the Americas. Previous mitochondrial analysis from coastal populations identified deeply divergent (up to 1 Mya) eastern and western lineages that predate most intraspecific splits in carnivores. We conducted genotyping by sequencing and mitochondrial analysis on gray foxes sampled across North America to determine geographic concordance between nuclear and mitochondrial contact zones and divergence times. We also estimated the admixture within the contact zone between eastern and western gray foxes based on nuclear DNA. Both datasets confirmed that …

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 …

The Past, Present, And Future Of Equine Science, Sarah H. White-Springer, Jason E. Bruemmer, Robert J. Coleman

United States Department of Agriculture Wildlife Services: Staff Publications

A core group of 27 equine nutritionists and physiologists joined together in the late 1960s to formally address and enhance the direction of equine research, creating the Equine Nutrition and Physiology Soci- ety. In 2003, that growing society transformed into the Equine Science Society, which now serves as the preeminent, internationally recognized scientific equine organization. In recent years, it has been appre- ciated that equine science encompasses a wide range of focus areas, including exercise science, nutrition, genetics, reproductive physiology, teaching and extension, production and management, and mix of other specialties, qualified as biosciences. Additionally, trainees are highly valued in …

Integrating Robotics Into Wildlife Conservation: Testing Improvements To Predator Deterrents Through Movement, Stewart W. Breck, Jeffrey T. Schultz, David Prause, Cameron Krebs, Anthony J. Giordano, Byron Boots

United States Department of Agriculture Wildlife Services: Staff Publications

Background Agricultural and pastoral landscapes can provide important habitat for wildlife conservation, but sharing these landscapes with wildlife can create conflict that is costly and requires managing. Livestock predation is a good example of the challenges involving coexistence with wildlife across shared landscapes. Integrating new technology into agricultural practices could help minimize human-wildlife conflict. In this study, we used concepts from the fields of robotics (i.e., automated movement and adaptiveness) and agricultural practices (i.e., managing livestock risk to predation) to explore how integration of these concepts could aid the development of more effective predator deterrents.

Methods …

Transmission Of Sars-Cov-2 In Free-Ranging White-Tailed Deer In The United States, Aijing Feng, Sarah Bevins, Jeff Chandler, Thomas J. Deliberto, Ria Ghai, Kristina Lantz, Julianna Lenoch, Adam Retchless, Susan A. Shriner, Cynthia Y. Tang, Suxiang Sue Tong, Mia Torchetti, Anna Uehara, Xiu-Feng Wan

United States Department of Agriculture Wildlife Services: Staff Publications

SARS-CoV-2 is a zoonotic virus with documented bi-directional transmission between people and animals. Transmission of SARS-CoV-2 from humans to free-ranging white-tailed deer (Odocoileus virginianus) poses a unique public health risk due to the potential for reservoir establishment where variantsmay persist and evolve. We collected 8,830 respiratory samples from free-ranging white-tailed deer across Washington, D.C. and 26 states in the United States between November 2021 and April 2022. We obtained 391 sequences and identified 34 Pango lineages including the Alpha, Gamma, Delta, and Omicron variants. Evolutionary analyses showed these white-tailed deer viruses originated fromat least 109 independent spillovers fromhumans,which resulted in …

A Social Network Analysis Of Actors Involved In Wild Pig (Sus Scrofa) Management In Missouri, Hailey E. Ellis, Meredith J. Grady, Lauren Jaebker, Alan D. Bright, Keith M. Carlisle

United States Department of Agriculture Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) cause significant damage to agriculture and native ecosystems and can transmit diseases to animals and people. Management responses designed to reduce population numbers are needed to mitigate these threats. Identifying networks of key actors, including the ways in which they interact, is valuable for purposes of better understanding opportunities or constraints that generate or impede effective management responses. The goal of our study was to understand the network of organizations, and the personnel working within them, that were active in wild pig management, research, or policy initiatives in Missouri during 2018–2020 by 1) identifying …

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

United States Department of Agriculture Wildlife Services: Staff Publications

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

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

United States Department of Agriculture Wildlife Services: Staff Publications

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

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

United States Department of Agriculture Wildlife Services: Staff Publications

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

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

United States Department of Agriculture Wildlife Services: Staff Publications

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

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

United States Department of Agriculture Wildlife Services: Staff Publications

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

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

United States Department of Agriculture Wildlife Services: Staff Publications

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

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

United States Department of Agriculture Wildlife Services: Staff Publications

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

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

United States Department of Agriculture Wildlife Services: Staff Publications

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

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

United States Department of Agriculture Wildlife Services: Staff Publications

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

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

United States Department of Agriculture Wildlife Services: Staff Publications

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

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

United States Department of Agriculture Wildlife Services: Staff Publications

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

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

United States Department of Agriculture Wildlife Services: Staff Publications

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

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

United States Department of Agriculture Wildlife Services: Staff Publications

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