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

Gulls As Sources Of Environmental Contamination By Colistin-Resistant Bacteria, Alan B. Franklin, Andrew M. Ramey, Kevin T. Bentler, Nicole L. Barrett, Loredana M. Mccurdy, Christina A. Ahlstrom, Jonas Bonnedahl, Susan A. Shriner, Jeffrey C. Chandler

United States Department of Agriculture Wildlife Services: Staff Publications

In 2015, the mcr-1 gene was discovered in Escherichia coli in domestic swine in China that conferred resistance to colistin, an antibiotic of last resort used in treating multi-drug resistant bacterial infections in humans. Since then, mcr-1 was found in other human and animal populations, including wild gulls. Because gulls could disseminate the mcr-1 gene, we conducted an experiment to assess whether gulls are readily colonized with mcr-1 positive E. coli, their shedding patterns, transmission among conspecifics, and environmental deposition. Shedding of mcr-1 E. coli by small gull flocks followed a lognormal curve and gulls shed one strain >101 …

Mixed Ancestry From Wild And Domestic Lineages Contributes To The Rapid Expansion Of Invasive Feral Swine, Timothy J. Smyser, Michael A. Tabak, Chris Slootmaker, Michael S. Robeson Ii, Ryan S. Miller, Mirte Bosse, Hendrik-Jan Megens, Martien A.M. Groenen, Samuel Rezende Paiva, Danielle Assis De Faria, Harvey D. Blackburn, Brandon S. Schmit, Antoinette J. Piaggio

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive alien species are a significant threat to both economic and ecological systems. Identifying the processes that give rise to invasive populations is essential for implementing effective control strategies. We conducted an ancestry analysis of invasive feral swine (Sus scrofa, Linnaeus, 1758), a highly destructive ungulate that is widely distributed throughout the contiguous United States, to describe introduction pathways, sources of newly emergent populations and processes contributing to an ongoing invasion. Comparisons of high-density single nucleotide polymorphism genotypes for 6,566 invasive feral swine to a comprehensive reference set of S. scrofa revealed that the vast majority of feral swine were …

Effects Of Wild Pig Disturbance On Forest Vegetation And Soils, Steven M. Gray, Gary J. Roloff, Daniel B. Kramer, Dwayne R. Etter, Kurt C. Vercauteren, Robert A. Montgomery

United States Department of Agriculture Wildlife Services: Staff Publications

In North America, wild pigs (Sus scrofa; feral pigs, feral swine, wild boars) are a widespread exotic species capable of creating large‐scale biotic and abiotic landscape perturbations. Quantification of wild pig environmental effects has been particularly problematic in northern climates, where they occur only recently as localized populations at low densities. Between 2016 and 2017, we assessed short‐term (within ~2 yrs of disturbance) effects of a low‐density wild pig population on forest features in the central Lower Peninsula of Michigan, USA. We identified 16 8‐ha sites using global positioning system locations from 7 radio‐collared wild pigs for sampling.Within each …

Timing And Extent Of Crop Damage By Wild Pigs (Sus Scrofa Linnaeus) To Corn And Peanut Fields, C. M. Boyce, Kurt C. Vercauteren, James C. Beasley

United States Department of Agriculture Wildlife Services: Staff Publications

The global expansion of wild pigs over the last few decades has resulted in an increase in extent and distribution of damages to crops, placing a growing strain on agricultural producers and land managers. Despite the extent of wild pig damage to agriculture, there is little data regarding timing and spatial variability of damage to corn (Zea mays Linnaeus) and we found no data regarding the effect of these factors on peanuts (Arachis hypogaea Linnaeus). Our objective was to determine the timing and extent of wild pig damage to corn and peanut fields, as well as the extent …

Validation Of A Screening Method For The Detection Of Colistin-Resistant E. Coli Containing Mcr-1 In Feral Swine Feces, Jeffrey C. Chandler, Alan B. Franklin, S. N. Bevins, Kevin T. Bentler, Jonas Bonnedahl, Christina A. Ahlstrom, Bledar Bisha, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

A method was developed and validated for the detection of colistin-resistant Escherichia coli containing mcr-1 in the feces of feral swine. Following optimization of an enrichment method using EC broth supplemented with colistin (1 μg/mL) and vancomycin (8 μg/mL), aliquots derived from 100 feral swine fecal samples were spiked with of one of five different mcr-1 positive E. coli strains (between 10⁰ and 10⁴ CFU/g), for a total of 1110 samples tested. Enrichments were then screened using a simple boil-prep and a previously developed real-time PCR assay for mcr-1 detection. The sensitivity of the method was determined in …

Placebo Oral Rabies Vaccine Bait Uptake By Small Indian Mongooses (Herpestes Auropunctatus) In Southwestern Puerto Rico, Are R. Berentsen, Richard B. Chipman, Kathleen M. Nelson, Kenneth S. Gruver, Frank Boyd, Steven F. Volker, Amy J. Davis, Ad Vos, Steffen Ortmann, Amy Gilbert

United States Department of Agriculture Wildlife Services: Staff Publications

The small Indian mongoose (Herpestes auropunctatus) is a rabies reservoir in areas of the Caribbean including Puerto Rico, but no rabies vaccination program targeting this host exists. We used two derivatives of iophenoxic acid (IPA) to evaluate placebo oral rabies vaccine bait uptake by mongooses in southwestern Puerto Rico. We hand-distributed baits at an application rate of 200 baits/km² at three, 400 ha, sites during autumn 2016 and spring 2017. Each site contained 90–100 cage traps in a 100 ha central trapping area. We used ethyl-IPA as a biological marker during the autumn and methyl-IPA during the …

Bird-Livestock Interactions Associated With Increased Cattle Fecal Shedding Of Ciprofloxacin-Resistant Escherichia Coli Within Feedlots In The United States, James C. Carlson, Jeffrey C. Chandler, Bledar Bisha, Jeffrey T. Lejeune, Thomas E. Wittum

United States Department of Agriculture Wildlife Services: Staff Publications

This research study was conducted to determine if bird depredation in feedlots is associated with the prevalence of ciprofloxacin-resistant Escherichia coli in cattle and to determine if removal of invasive bird species could be an effective management strategy to help reduce ciprofloxacin-resistant E. coliin cattle within the United States. european starlings (Sturnus vulgaris) were collected from feedlots within multiple geographic regions within the United States and european starlings within all regions tested positive for ciprofloxacin-resistant E. coli, but prevalence differed by region. Total number of birds on feedlots were positively associated with increased cattle fecal shedding of ciprofloxacin-resistant E. coli. …

The Role Of European Starlings (Sturnus Vulgaris) In The Dissemination Of Multidrug- Resistant Escherichia Coli Among Concentrated Animal Feeding Operations, Jeffrey C. Chandler, Jennifer E. Anders, Nicolas A. Blouin, James C. Carlson, Jeffrey T. Lejeune, Lawrence D. Goodridge, Baolin Wang, Leslie A. Day, Anna M. Mangan, Dustin A. Reid, Shannon M. Coleman, Matthew W. Hopken, Bledar Bisha

United States Department of Agriculture Wildlife Services: Staff Publications

Antimicrobial use in livestock production is a driver for the development and proliferation of antimicrobial resistance (AMR). Wildlife interactions with livestock, acquiring associated AMR bacteria and genes, and wildlife’s subsequent dispersal across the landscape are hypothesized to play an important role in the ecology of AMR. Here, we examined priority AMR phenotypes and genotypes of Escherichia coli isolated from the gastrointestinal tracts of european starlings (Sturnus vulgaris) found on concentrated animal feeding operations (CAFOs). European starlings may be present in high numbers on cAfos (>100,000 birds), interact with urban environments, and can migrate distances exceeding 1,500 km in North …

Fish-Eating Birds On Catfish Ponds In The Mississippi Delta, Paul Burr, Jimmy Avery, Garrett Street, Bronson Strickland, Brian Dorr

United States Department of Agriculture Wildlife Services: Staff Publications

Catfish acreage in the Mississippi Delta has significantly declined in the past two decades, but cormorant density on catfish ponds has remained the same. One possible explanation is that there are fewer cormorants in the region, and this is supported with decreasing roost counts. Cormorant roost harassment can be even more effective today than in the past, because there is less aquaculture acreage to protect and fewer cormorants to move. Roost harassment is important over the entire winter, but even more so around mid-January when cormorant abundance is greatest and when cormorants are more focused on aquaculture ponds. The addition …

Cormorant Predation Of Commercial Catfish Aquaculture In The Mississippi Delta, Terrel Christie, Brian Dorr, Luke Roy, Anita M. Kelly, Carole Engle, Paul Burr, Brian Davis, Jonathan Van Senten

United States Department of Agriculture Wildlife Services: Staff Publications

Catfish aquaculture is an important agricultural commodity in Mississippi with most of the production. occurring in the Delta region of the state. A vital factor in managing these farms is reducing fish loss from bird depredation. The most notable bird species that consume catfish are Double-crested Cormorants. These migratory waterbirds arrive in fall and remain in the region throughout winter. Cormorant interactions with catfish aquaculture have previously been studied, but recent changes in the industry warrant collection of new data to understand the dynamic between catfish aquaculture and cormorants. The Southern Regional Aquaculture Center recently funded a study to estimate …

Predator Scent And Visual Cue Applied To Nest Boxes Fail To Dissuade European Starlings (Sturnus Vulgaris) From Nesting, Bradley Blackwell, Thomas W. Seamans, Morgan Pfeiffer, Bruce N. Buckingham

United States Department of Agriculture Wildlife Services: Staff Publications

Indirect predator cues have been shown to enhance perceived nest predation risk in both open-cup and cavity-nesting birds. We hypothesized that scent from the raccoon (Procyon lotor) inside nest boxes, supplemented with raccoon hair as a visual cue on the outside of the box, would enhance perceived risk to the European Starling (Sturnus vulgaris), resulting in reduced use of treated nest boxes and negative effects on reproduction. The starling is recognized, outside its native range, as a competitor with indigenous cavity nesters and a pest species, and efforts to deter its nesting have generally been unsuccessful. …

Factors And Costs Associated With Removal Of A Newly Established Population Of Invasive Wild Pigs In Northern U.S., Justin W. Fischer, Nathan P. Snow, Bradley E. Wilson, Scott F. Beckerman, Christopher N. Jacques, Eric H. Vannatta, Shannon L. Kay, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

The human-mediated spread of exotic and invasive species often leads to unintentional and harmful consequences. Invasive wild pigs (Sus scrofa) are one such species that have been repeatedly translocated throughout the United States and cause extensive damage to natural ecosystems, threatened and endangered species, agricultural resources, and private lands. In 2005, a newly established population of wild pigs was confirmed in Fulton County, Illinois, U.S. In 2011, a state-wide wild pig damage management program involving federal, state, and local government authorities directed a concerted effort to remove wild pigs from the county until the last wild pig (of 376 total) …

Reporting The Limits Of Detection And Quantification For Environmental Dna Assays, Katy E. Klymus, Christopher M. Merkes, Michael J. Allison, Caren S. Goldberg, Caren C. Helbing, Margaret E. Hunter, Craig A. Jackson, Richard F. Lance, Anna M. Mangan, Emy M. Monroe, Antoinette J. Piaggio, Joel P. Stokdyk, Chris C. Wilson, Catherine A. Richter

United States Department of Agriculture Wildlife Services: Staff Publications

Background: Environmental DNA (eDNA) analysis is increasingly being used to detect the presence and relative abundance of rare species, especially invasive or imperiled aquatic species. The rapid progress in the eDNA field has resulted in numerous studies impacting conservation and management actions. However, standardization of eDNA methods and reporting across the field is yet to be fully established, with one area being the calculation and interpretation of assay limit of detection (LOD) and limit of quantification (LOQ).

Aims: Here, we propose establishing consistent methods for determining and reporting of LOD and LOQ for single‐species quantitative PCR (qPCR) eDNA studies.

Materials …

Safety, Immunogenicity, And Efficacy Of Intramuscular And Oral Delivery Of Era-G333 Recombinant Rabies Virus Vaccine To Big Brown Bats (Eptesicus Fuscus), Amy T. Gilbert, Xianfu Wu, Felix R. Jackson, Richard Franka, Gary F. Mccracken, Charles E. Rupprecht

United States Department of Agriculture Wildlife Services: Staff Publications

Attenuated strains of rabies virus (RABV) have been used for oral vaccination of wild carnivores in Europe and North America. However, some RABV vaccines caused clinical rabies in target animals. To improve the safety of attenuated RABV as an oral vaccine for field use, strategies using selection of escape mutants under monoclonal antibody neutralization pressure and reverse genetics–defined mutations have been used. We tested the safety, immunogenicity, and efficacy of one RABV construct, ERA-g333, developed with reverse genetics by intramuscular (IM) or oral (PO) routes in big brown bats (Eptesicus fuscus). Twenty-five bats received 5×10⁶ mouse intracerebral …

Effects Of Brodifacoum And Diphacinone Exposure On Four Species Of Reptiles: Tissue Residue Levels And Survivorship, Richard E. Mauldin, Gary W. Witmer, S. A. Shriner, Rachael S. Moulton, Katherine E. Horak

United States Department of Agriculture Wildlife Services: Staff Publications

BACKGROUND: Anticoagulant rodenticides are used worldwide to control pest rodent species. However, the risks posed to nontarget reptiles have not been well characterized. In this study, 46 giant ameivas (Ameiva ameiva), 39 boa constrictors (Boa constrictor), 33 wood turtles (Rhinoclemmys pulcherrima), and 47 green iguanas (Iguana iguana) were orally dosed with one of two levels of either diphacinone or brodifacoum anticoagulant in propylene glycol solutions. Dosages were derived using daily food intake (DFI) equations, converting DFI to an equivalent anticoagulant bait amount and gavaging the solution volume needed to deliver the quantity of anticoagulant in that amount of bait. Animals …

Cattle Egrets Regurgitate House Mouse Carcasses Onto A Mouse-Free Island: Implications For Rodent Eradications, Aaron B. Shiels, Mele Khalsa, Doreen L. Griffin, Clay K. Chow, Sheri S. Mann, Antoinette J. Piaggio

United States Department of Agriculture Wildlife Services: Staff Publications

Context. Eradication of invasive rodents on islands typically results in positive conservation gains, and maintaining a rodent-free island requires elevated biosecurity, including prevention of assisted rodent arrival via watercraft, aircraft and animals such as birds. Cattle egrets (Bubulcus ibis) are widespread, and often fly several kilometres daily to roost and forage. They frequently swallow insects and vertebrates (including rodents) whole, and some regurgitate prey. Cattle egrets have been regularly observed flying between the Hawaiian Islands of Ni’ihau (where non-native mice and rats are established) and Lehua (where one species of non-native rat is established and was targeted during …

Conspecific Chemical Cues Facilitate Mate Trailing By Invasive Argentine Black And White Tegus, Shannon A. Richard, Isabella M. G. Bukovich, E. A. Tillman, Sanjiv Jayamohan, J. S. Humphrey, Paige E. Carrington, William E. Bruce, Bryan M. Kluever, Michael L. Avery, M. Rockwell Parker

United States Department of Agriculture Wildlife Services: Staff Publications

Squamate reptiles (snakes and lizards) rely on chemical cues from conspecifics to search the environment for potential mates. How such cues are used by invasive species to facilitate reproduction, especially seasonally, is a key question that can inform management practices. The Argentine black and white tegu (Salvator merianae) is an invasive reptile species in south Florida threatening native fauna in biodiverse regions such as Everglades National Park. While some information exists on the reproductive ecology of this species in its native range in South America, the chemical ecology of S. merianae is unclear especially in its invasive range. By testing …

Optimal Spatial Prioritization Of Control Resources For Elimination Of Invasive Species Under Demographic Uncertainty, Kim M. Pepin, Timothy J. Smyser, Amy J. Davis, Ryan S. Miller, Sophie Mckee, Kurt C. Vercauteren, William Kendall, Chris Slootmaker

United States Department of Agriculture Wildlife Services: Staff Publications

Populations of invasive species often spread heterogeneously across a landscape, consisting of local populations that cluster in space but are connected by dispersal. A fundamental dilemma for invasive species control is how to optimally allocate limited fiscal resources across local populations. Theoretical work based on perfect knowledge of demographic connectivity suggests that targeting local populations from which migrants originate (sources) can be optimal. However, demographic processes such as abundance and dispersal can be highly uncertain, and the relationship between local population density and damage costs (damage function) is rarely known. We used a metapopulation model to understand how budget and …

A Comparison Of Cost And Quality Of Three Methods For Estimating Density For Wild Pig (Sus Scrofa), Amy J. Davis, David A. Keiter, Elizabeth M. Kierepka, C. Slootmaker, Antoinette J. Piaggio, James C. Beasley, K. M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

A critical element in effective wildlife management is monitoring the status of wildlife populations; however, resources to monitor wildlife populations are typically limited. We compared cost effectiveness of three common population estimation methods (i.e. non-invasive DNA sampling, camera sampling, and sampling from trapping) by applying them to wild pigs (Sus scrofa) across three habitats in South Carolina, U.S.A where they are invasive. We used mark-recapture analyses for fecal DNA sampling data, spatially-explicit capture-recapture analyses for camera sampling data, and a removal analysis for removal sampling from trap data. Density estimates were similar across methods. Camera sampling was the least expensive, …

Technical Limitations Associated With Molecular Barcoding Of Arthropod Bloodmeals Taken From North American Deer Species, Erin M. Borland, Daniel A. Hartman, Matthew W. Hopken, Antoinette J. Piaggio, Rebekah C. Kading

United States Department of Agriculture Wildlife Services: Staff Publications

Accurate species-level identification of the source of arthropod bloodmeals is important for deciphering blood feeding patterns of field-collected specimens. Cytochrome c oxidase I (COI) mitochondrial gene sequencing has been used for this purpose; however, species resolution can be difficult to obtain from certain vertebrate genera, including Odocoileus. Sanger sequencing of mitochondrial genes was employed to identify the bloodmeal source of wild-caught mosquitoes trapped in Greeley, Colorado. Initial sequencing of the COI gene of mitochondrial DNA in bloodmeals was inadequate for species-level resolution of bloodmeals from deer in the genus Odocoileus, with current databases returning low fidelity matches to …