Life Sciences Commons^™

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

USDA 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 …

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

USDA 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 …

How Do Genetic Relatedness And Spatial Proximity Shape African Swine Fever Infections In Wild Boar?, Tomasz Podgórski, Kim M. Pepin, Anna Radko, Angelika Podbielska, Magdalena Łyjak, Grzegorz Woźniakowski, Tomasz Borowik

USDA Wildlife Services: Staff Publications

The importance of social and spatial structuring of wildlife populations for disease spread, though widely recognized, is still poorly understood in many host-pathogen systems. In particular, system-specific kin relationships among hosts can create contact heterogeneities and differential disease transmission rates. Here, we investigate how distance-dependent infection risk is influenced by genetic relatedness in a novel host-pathogen system: wild boar (Sus scrofa) and African swine fever (ASF).We hypothesized that infection risk would correlate positively with proximity and relatedness to ASF-infected individuals but expected those relationships to weaken with the distance between individuals due to decay in contact rates and …

Multi-Level Movement Response Of Invasive Wild Pigs (Sus Scrofa) To Removal, Guillaume Bastille-Rousseau, Peter E. Schlichting, David A. Keiter, Joshua B. Smith, John C. Kilgo, George Wittemyer, Kurt C. Vercauteren, James C. Beasley, Kim M. Pepin

USDA Wildlife Services: Staff Publications

BACKGROUND: Lethal removal of invasive species, such as wild pigs (Sus scrofa), is often the most efficient approach for reducing their negative impacts. Wild pigs are one of the most widespread and destructive invasive mammals in the USA. Lethal management techniques are a key approach for wild pigs and can alter wild pig spatial behavior, but it is unclear how wild pigs respond to the most common removal technique, trapping.We investigated the spatial behavior of wild pigs following intensive removal of conspecifics via trapping at three sites within the Savannah River Site, SC, USA. We evaluated changes in …

Anthraquinone Repellent Seed Treatment On Corn Reduces Feeding By Wild Pigs, Nathan P. Snow, Joseph M. Halseth, Scott J. Werner, Kurt C. Vercauteren

USDA Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) are a destructive invasive species that cause extensive damage to agriculture throughout many regions of the world. In particular wild pigs damage corn more than any other crop, and most of that damage occurs immediately after planting when wild pigs excavate and consume planted seeds. We evaluated whether anthraquinone (AQ), a repellent, could be useful for protecting seed corn from consumption by wild pigs. Specifically, we conducted cafeteria-style tests at 16 bait sites for 6 nights using concentrations of: untreated, 0.5, 1.5, and 3.0% AQ by weight sprayed on whole-kernel corn in AL and …

Daily And Landscape Influences Of Species Visitation To Toxic Bait Sites For Wild Pigs, Nathan P. Snow, Joseph M. Halseth, Michael P. Glow, Michael Lavelle, Justin Fischer, Eric H. Vannatta, Kurt C. Vercauteren

USDA Wildlife Services: Staff Publications

Toxic baiting of wild pigs (Sus scrofa) is a potential new tool for population control and damage reduction in the United States. Use of toxic bait sites by non‐target species is concerning because of the risks posed from exposure to a toxic bait. A 2018 field trial in northern Texas, USA, examining the efficacy of a prototype toxic bait (HOGGONE®, containing 10% sodium nitrite) revealed unexpected hazards to non‐target species, primarily passerine birds, from consuming toxic bait spilled outside of bait stations by wild pigs. The hazards jeopardize the ability to register HOGGONE as a tool for controlling …

Efficacy And Risks From A Modified Sodium Nitrite Toxic Bait For Wild Pigs, Nathan P. Snow, Jason Wishart, Justin A. Foster, Linton D. Staples, Kurt C. Vercauteren

USDA Wildlife Services: Staff Publications

BACKGROUND: Wild pigs (Sus scrofa) are a destructive invasive species throughout many regions of the world. In 2018, a field evaluation of an early prototype of a sodium nitrite (SN) toxic bait in the United States revealed wild pigs dropped large amounts of the toxic bait outside the pig-specific bait stations while feeding, and thus subsequent hazards for non-target animals. We modified the SN-toxic bait formulation, the design of the bait station, and the baiting strategy to reduce dropped bait. We tested the modifications in Queensland, Australia (December 2018), Alabama, USA (August 2019), and Texas, USA (March 2020) …

Social Structure Defines Spatial Transmission Of African Swine Fever In Wild Boar, Kim M. Pepin, Andrew J. Golnar, Tomasz Podgórski

USDA Wildlife Services: Staff Publications

The spatial spread of infectious disease is determined by spatial and social processes such as animal space use and family group structure. Yet, the impacts of social processes on spatial spread remain poorly understood and estimates of spatial transmission kernels (STKs) often exclude social structure. Understanding the impacts of social structure on STKs is important for obtaining robust inferences for policy decisions and optimizing response plans. We fit spatially explicit transmission models with different assumptions about contact structure to African swine fever virus surveillance data from eastern Poland from 2014 to 2015 and evaluated how social structure affected inference of …

Ecological Drivers Of African Swine Fever Virus Persistence In Wild Boar Populations: Insight For Control, Kim M. Pepin, Andrew J. Golnar, Zaid Abdo, Tomasz Podgórski

USDA Wildlife Services: Staff Publications

Environmental sources of infection can play a primary role in shaping epidemiological dynamics; however, the relative impact of environmental transmission on host-pathogen systems is rarely estimated. We developed and fit a spatially explicit model of African swine fever virus (ASFV) in wild boar to estimate what proportion of carcassbased transmission is contributing to the low-level persistence of ASFV in Eastern European wild boar. Our model was developed based on ecological insight and data from field studies of ASFV and wild boar in Eastern Poland. We predicted that carcass- based transmission would play a substantial role in persistence, especially in low-density …

Low Secondary Risks For Captive Coyotes From A Sodium Nitrite Toxic Bait For Invasive Wild Pigs, Nathan P. Snow, Katherine E. Horak, Simon T. Humphrys, Linton D. Staples, David G. Hewitt, Kurt C. Vercauteren

USDA Wildlife Services: Staff Publications

An acute toxic bait is being developed to deliver micro‐encapsulated sodium nitrite (SN) to stimulate severe methemoglobinemia and humane death for invasive wild pigs (Sus scrofa), thereby providing a new tool for reducing their populations. During April 2016, we evaluated sensitivity to SN and outcomes of secondary consumption in the ubiquitous mammalian scavenger, coyote (Canis latrans), to determine secondary risks of consuming carcasses of wild pigs that died from consuming the SN toxic bait. At the National Wildlife Research Center in Fort Collins, Colorado, USA, we first evaluated whether coyotes fed carcasses of domestic pigs killed by consumption of SN …

Movement Responses Inform Effectiveness And Consequences Of Baiting Wild Pigs For Population Control, Nathan P. Snow, Kurt C. Vercauteren

USDA Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) damage agricultural and natural resources throughout their nearly global distribution. Subsequently, population control activities (e.g., trapping, shooting, or toxic baiting) frequently involve the deployment of bait to attract wild pigs. A better understanding of how wild pigs respond to bait sites can help maximize efficiency of baiting programs and identify any potential pitfalls. We examined the movement behaviors of 68 wild pigs during three stages of intensive baiting programs (i.e., 15 days each: prior, during, and post baiting) spread across two distinct study areas in southern and northern Texas, USA. We found that bait sites needed …

Feral Swine Harming Insular Sea Turtle Reproduction: The Origin, Impacts, Behavior And Elimination Of An Invasive Species, Richard M. Engeman, Robert W. Byrd, Jamie Dozier, Mark A. Mcalister, James O. Edens, Elizabeth M. Kierepka, Timothy J. Smyser, Noel Myers

USDA Wildlife Services: Staff Publications

Feral swine are among the world's most destructive invasive species wherever they are found, with translocations figuring prominently in their range expansions. In contrast, sea turtles are beloved species that are listed as threatened or endangered throughout the world and are the focus of intense conservation efforts. Nest predation by feral swine severely harms sea turtle reproduction in many locations around the world. Here we quantify and economically assess feral swine nest predation at North Island, South Carolina, an important loggerhead sea turtle nesting beach. Feral swine depredation of North Island sea turtle nests was first detected in 2005, with …

Molecular Population Structure For Feral Swine In The United States, Blake E. Mccann, Timothy J. Smyser, Brandon S. Schmit, Robert A. Newman, Antoinette J. Piaggio, Mathew J. Malek, Seth R. Swafford, Richard A. Sweitzer, Rebecca B. Simmons

USDA Wildlife Services: Staff Publications

Feral swine (Sus scrofa) have invaded most of the United States and continue to expand throughout North America. Given the ecological and economic threats posed by increasing feral swine abundance, it is imperative to develop an understanding of their patterns of natural range expansion and human-mediated introductions. Towards this goal, we used molecular markers to elucidate the genetic structure of feral swine populations throughout the United States and evaluated the association between historical introductions and contemporary patterns of genetic organization. We used STRUCTURE and discriminant analysis of principal components (DAPC) to delineate genetic clusters for 959 individuals genotyped …

Development And Evaluation Of A Bait Station For Selectively Dispensing Bait To Invasive Wild Pigs, Michael Lavelle, Nathan P. Snow, Joe M. Halseth, John C. Kinsey, Justin A. Foster, Kurt C. Vercauteren

USDA Wildlife Services: Staff Publications

Populations of invasive wild pigs (Sus scrofa; hereafter, wild pigs) are expanding, requiring cost effective tools for control, and disease prevention, such as toxic or vaccine baits. Specifically, development of a novel and humane toxicant is underway for control of wild pigs in the United States and Australia. A species specific bait station for delivering the toxic bait must be used to protect nontarget animals. Further, a bait station must be designed to maximize feeding by wild pigs by accommodating their group-feeding behaviors.We sought to develop a bait station that delivered bait to the maximum proportion of wild …

Potential Secondary Poisoning Risks To Non-Targets From A Sodium Nitrite Toxic Bait For Invasive Wild Pigs, Nathan P. Snow, Justin A. Foster, Eric H. Vannatta, Katherine E. Horak, Simon T. Humphrys, Linton D. Staples, David G. Hewitt, Kurt C. Vercauteren

USDA Wildlife Services: Staff Publications

BACKGROUND: An acute and orally delivered toxic bait containing micro-encapsulated sodium nitrite (MESN), is under development to provide a novel and humane technology to help curtail damage caused by invasive wild pigs (Sus scrofa). We evaluated potential secondary risks for non-target species by: testing whether four different types of micro-encapsulation coatings could reduce vomiting by invasive wild pigs, testing the levels of residual sodium nitrite (SN) in tissues of invasive wild pigs, testing the environmental persistence of SN in vomitus, and conducting a risk assessment for scavengers.

RESULTS: Micro-encapsulation coatings did not affect the frequency of …

Development Of Toxic Bait To Control Invasive Wild Pigs And Reduce Damage, Nathan P. Snow, Justin A. Foster, John C. Kinsey, Simon T. Humphrys, Linton D. Staples, David G. Hewitt, Kurt C. Vercauteren

USDA Wildlife Services: Staff Publications

Populations of invasive wild pigs (Sus scrofa) are increasing in many regions of the world, in particular the United States and Australia. Invasive wild pigs cause extensive damage to ecological resources and agriculture. Development and registration of a safe and humane toxic bait offers a practical and cost effective tool to control invasive species. Currently, no toxicants are approved for use on invasive wild pigs in the United States and those approved in Australia are under scrutiny because of concerns regarding humaneness and effects on nontarget species. We tested a newly formulated bait containing the microencapsulated active ingredient, …

Interpreting And Predicting The Spread Of Invasive Wild Pigs, Nathan P. Snow, Marta A. Jarzyna, Kurt C. Vercauteren

USDA Wildlife Services: Staff Publications

1. The eruption of invasive wild pigs (IWPs) Sus scrofa throughout the world exemplifies the need to understand the influences of exotic and nonnative species expansions. In particular, the continental USA is precariously threatened by a rapid expansion of IWPs, and a better understanding of the rate and process of spread can inform strategies that will limit the expansion.

2. We developed a spatially and temporally dynamic model to examine three decades (1982– 2012) of IWP expansion, and predict the spread of IWPs throughout the continental USA, relative to where IWPs previously inhabited. We used the model to predict where …