Digital Commons Network^™

Characterization Of Recent Wild Pig‑Vehicle Collisions In Georgia, Usa, Jeremiah L. Psiropoulos, Emily Howe, John J. Mayer, Sophie C. Mckee

USDA Wildlife Services: Staff Publications

Vehicle collisions with wild pigs (Sus scrofa) are reported almost everywhere this species is found. However, this is one of the least studied and characterized forms of damage that these invasive animals cause in the United States (US). We analyzed 518 wild pig-vehicle collisions (WPVCs) that took place statewide in Georgia between 2015 and 2021. From that dataset, we analyzed several parameters in order to better understand and characterize these accidents on a scale that had previously not been done in the US. Wild pig-vehicle collisions were reported from 105 out of the 159 counties in Georgia, increasing …

Seasonal Efficacy And Risks From A Sodium Nitrite Toxic Bait For Wild Pigs, Nathan P. Snow, Michael P. Glow, Justin A. Foster, Kurt C. Vancauteren

USDA Wildlife Services: Staff Publications

Background
Wild pigs (Sus scrofa) are an invasive and destructive species throughout many regions of the world. A sodium nitrite (SN) toxic bait is currently used in Australia and being developed for use in the US and other countries to combat the increasing populations of wild pigs. In the US, efforts to modify the Australian SN-toxic bait and baiting strategy have focused on reducing issues with non-target animals accessing the SN-toxic bait spilled outside of bait stations by wild pigs. We tested and compared modifications for efficacy (with wild pigs) and hazards (with non-targets) in north-central Texas, US during summer …

Comprehensive Economic Impacts Of Wild Pigs On Producers Of Six Crops In The South-Eastern Us And California, Sophie C. Mckee, John J. Mayer, Stephanie A. Shwiff

USDA Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) cause damage to agricultural crops in their native range as well asin the portions of the globe where they have been introduced. In the US, states with the highest introduced wild pig populations are Alabama, Arkansas, California, Florida, Georgia, Louisiana, Mississippi, Missouri, North Carolina, South Carolina, and Texas. The present study summarizes thefirst survey-based effort to value the full extent of wild pig damage to producers of six crops in these 11 US states. The survey was distributed by the USDA National Agricultural Statistical Service in the summer of 2022 to a sample of …

A Four-Pronged Approach To Addressing A Wild Pig Invasion In A Bottomland And Upland Forested Landscape, Tyler Scott Evans

Theses and Dissertations

Among exotic species that are capable of invading, establishing, and reaching pest status, few pose the range of impacts to biotic (e.g., competition with native species, predation, herbivory, introduction of other exotics) and abiotic (e.g., soil, hydrology) ecosystem components that can be attributed to the wild pig (Sus scrofa). Despite the presence of wild pigs throughout the southeastern United States for centuries, new invasions continue to occur in previously uninhabited and often under-investigated landscapes, including bottomland and upland forests. The recent invasion of the Sam D. Hamilton Noxubee National Wildlife Refuge (hereafter, NNWR) in east-central Mississippi represents an …

A Critical Look At Wild Pig Elimination: Myths And Facts, Kim M. Pepin, Travis L. Guerrant, Jeremiah L. Psiropoulos, Jeanine T. Neskey, John M. Tomeček, Michael J. Bodenchuk, Janean L. Romines

Human–Wildlife Interactions

Wild pigs (Sus scrofa) are abundant and widely distributed in the United States. They damage crops and pastures, predate livestock and sensitive species, impact ecosystem functions, and damage personal property. To address these issues, some states in the United States are seeking complete elimination. A frequently asked question by stakeholders is: “What portion of the population needs to be removed annually to reach elimination?” The number 70% is widely touted as the answer. There is little scientific evidence to support that this percent annual removal would be needed to achieve elimination, yet 70% has now become a standard …

Human Fatalities Resulting From Wild Pig Attacks Worldwide: 2000–2019, John J. Mayer, James E. Garabedian, John C. Kilgo

Human–Wildlife Interactions

Although reported to be rare, human fatalities resulting from wild pig (Sus scrofa) attacks do occur. Toward a better understanding of patterns in fatal wild pig attacks, we synthesized worldwide reports of wild pig attacks on humans between 2000 and 2019. We documented 163 separate reports of fatal wild pig attacks that resulted in 172 human deaths. On average, 8.6 human deaths occurred annually due to wild pig attacks during those 2 decades. The majority of fatal attacks resulted in a single human death; however, there were 6 cases in which an individual fatal attack resulted in 2–4 …

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

USDA 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 …

Using Drones To Detect And Quantify Wild Pig Damage And Yield Loss In Corn Fields Throughout Plant Growth Stages, Bethany A. Friesenhahn, Lori D. Massey, Randy W. Deyoung, Michael J. Cherry, Justin W. Fischer, Nathan P. Snow, Kurt C. Vercauteren, Humberto L. Perotto‐Baldivieso

USDA Wildlife Services: Staff Publications

Presently, there are an estimated 6.9 million wild pigs (Sus scrofa) in the U.S., which cause over US$1 billion in damage to agriculture, environmental impacts, and control costs. However, estimates of damage have varied widely, creating a need for standardized monitoring and a method to accurately estimate the economic costs of direct wild pig damage to agriculture. The goal of our study was to integrate remotely sensed imagery from drones and crop harvest data to quantify wild pig damage in corn fields. We used drones with natural color (red, green, blue) cameras to monitor corn fields at different …

Assessment Of Spilled Toxic Bait By Wild Pigs And Potential Risk To Non-Target Species, John C. Kinsey, Justin A. Foster, Nathan P. Snow, Jason D. Wishart, Linton D. Staples, Janis K. Bush, Kurt V. Vercauteren

USDA Wildlife Services: Staff Publications

Background

In 2018, a sodium nitrite (SN)-based toxic bait for invasive wild pigs (hereafter wild pigs; Sus scrofa), was evaluated to determine its effectiveness in reducing local wild pig populations in Texas. Localized population reductions of > 70% were achieved, but spillage of bait outside wild pig-specific feeders (bait stations) caused by feeding wild pigs resulted in the deaths of non-target animals. To evaluate risks to non-target animals, we tested whether bait presentation influenced the total amount of bait spilled by wild pigs and estimated the associated risk to non-target species.

Results

We found that bait spilled outside bait stations …

Changes In Wild Pig (Sus Scrofa) Relative Abundance, Crop Damage, And Environmental Impacts In Response To Control Efforts, Joseph W. Treichler, Kurt C. Vercauteren, Charles R. Taylor, James C. Beasley

USDA Wildlife Services: Staff Publications

Background

As the population and range of wild pigs (Sus scrofa) continue to grow across North America, there has been an increase in environmental and economic damages caused by this invasive species, and control efforts to reduce damages have increased concomitantly. Despite the expanding impacts and costs associated with population control of wild pigs, the extent to which wild pig control reduces populations and diminishes environmental and agricultural damages are rarely quantified.The goal of this study is to quantify changes in wild pig relative abundance and subsequent changes in damages caused by invasive wild pigs in response to …

Comparison Of Daily Activity Patterns Across Seasons Using Gps Telemetry And Camera Trap Data For A Widespread Mammal, David W. Wolfson, Peter E. Schlichting, Raoul K. Boughton, Ryan S. Miller, Kurt C. Vercauteren, Jesse S. Lewis

USDA Wildlife Services: Staff Publications

Daily activity patterns of animals can be dynamic across seasons in response to changing environmental conditions. Daily activity, though, has rarely been evaluated in relation to multiple factors (for example, seasons, demographics, and data collection methods), which could be important for understanding what drives activity patterns. Here, we evaluated the daily activity patterns of a widespread invasive species, wild pigs (Sus scrofa), across two ecologically different study areas at Buck Island Ranch, Florida, and Tejon Ranch, California (United States), from 2015 to 2018. Using GPS telemetry data (62 individuals in Florida, 21 individuals in California) and detections from …

Changes In Wild Pig (Sus Scrofa) Relative Abundance, Crop Damage, And Environmental Impacts In Response To Control Efforts, Joseph W. Treichler, Kurt C. Vercauteren, Charles R. Taylor, James C. Beasley

USDA Wildlife Services: Staff Publications

Background
As the population and range of wild pigs (Sus scrofa) continue to grow across North America, there has been an increase in environmental and economic damages caused by this invasive species, and control efforts to reduce damages have increased concomitantly. Despite the expanding impacts and costs associated with population control of wild pigs, the extent to which wild pig control reduces populations and diminishes environmental and agricultural damages are rarely quantified. The goal of this study is to quantify changes in wild pig relative abundance and subsequent changes in damages caused by invasive wild pigs in response to control. …

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

USDA 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 …

Type And Frequency Of Wild Pig-Domestic Livestock Contacts And Operator Concern For Disease Spread, Sophie C. Mckee, Daniel F. Mooney, Ryan S. Miller

USDA 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 …

Genomic Tools Reveal Complex Social Organization Of An Invasive Large Mammal (Sus Scrofa), Chelsea L. Titus, Courtney F. Bowden, Timothy J. Smyser, Stephen L. Webb, James C. Beasley

USDA Wildlife Services: Staff Publications

A comprehensive understanding of sociality in wildlife is vital to optimizing conservation and management efforts. However, sociality is complicated, especially for widely distributed species that exhibit substantive behavioral plasticity. Invasive wild pigs (Sus scrofa), often representing hybrids of European wild boar and domestic pigs, are among the most adaptable and widely distributed large mammals. The social structure of wild pigs is believed to be similar to European wild boar, consisting of matriarchal groups (sounders) and solitary males. However, wild pig social structure is understudied and largely limited to visual observations. Using a hierarchical approach, we incorporated genomic tools …

Effects Of Invasive Wild Pigs And Supplemental Feeding On Wildlife In The Piedmont Region Of South Carolina, Elizabeth A. Saldo

All Theses

Wild pigs (Sus scrofa), which are invasive in much of the world, can alter ecosystems and compete with native species through interference competition and resource exploitation. We assessed the potential for interspecific interactions between invasive wild pigs and other wildlife in the Piedmont region of South Carolina by examining their spatiotemporal overlap in a correlational field study and an experimental field study. Our correlational study used data from wildlife cameras in seasonal occupancy, N-mixture, and temporal overlap analyses. Both deer (Odocoileus virginianus) and coyote (Canis latrans) site use were negatively associated with wild pig …

A Review Of The Impacts Of Invasive Wild Pigs On Native Vertebrates, Matthew T. Mcdonough, Stephen S. Ditchkoff, Mark D. Smith, Kurt C. Vercauteren

USDA Wildlife Services: Staff Publications

The wild pig (Sus scrofa) is a successful invasive species that has become well established outside of its native range in Eurasia. The invasive wild pig is the result of released or escaped domesticated livestock becoming feral, or Eurasian boar introduced for hunting purposes. The global spread of wild pigs has recently been exacerbated in some areas, such as the USA, by anthropogenically assisted dispersal. Once established in novel ecosystems, wild pigs have the potential to have significant negative impacts on the ecosystem, and the scientific literature is replete with examples. It is generally accepted that wild pigs …

An Efficient Method Of Evaluating Multiple Concurrent Management Actions On Invasive Populations, Amy J. Davis, Randy Farrar, Brad Jump, Parker Hall, Travis Guerrant, Kim M. Pepin

USDA Wildlife Services: Staff Publications

Evaluating the efficacy of management actions to control invasive species is crucial for maintaining funding and to provide feedback for the continual improvement of management efforts. However, it is often difficult to assess the efficacy of control methods due to limited resources for monitoring. Managers may view effort on monitoring as effort taken away from performing management actions. We developed a method to estimate invasive species abundance, evaluate management effectiveness, and evaluate population growth over time from a combination of removal activities (e.g., trapping, ground shooting) using only data collected during removal efforts (method of removal, date, location, number of …

Texas Hunters’ Perceptions Regarding The Acceptability Of Toxicants To Control Wild Pig Populations, Keith M. Carlisle, Sophie Mckee, Hailey E. Ellis, Lauren M. Jaebker, John M. Tomeček, Alan D. Bright, Rachael L. Connally, Maureen G. Frank, Stephanie A. Shwiff

Human–Wildlife Interactions

Wild pigs (Sus scrofa) are an invasive species in the United States. They damage agriculture, degrade water quality and ecological communities, and host a number of viruses, parasites, and bacteria transmissible to humans and animals. In states such as Texas, USA, where wild pigs cause extensive damage to agriculture and property, officials have considered allowing for the use of toxicants to control wild pig populations. To provide decision-makers with information regarding stakeholders’ perceptions of the use of toxicants to control wild pigs, we surveyed Texas hunters in 2019 to assess the level of acceptance of a hypothetical wild …

An Examination Of Ethical Attitudes Towards Wild Pig (Sus Scrofa) Toxicants In The United States, Keith Carlisle, Erin E. Harper, Stephanie A. Shwiff

USDA Wildlife Services: Staff Publications

This research aims to understand ethical attitudes of the U.S. public towards the use of a toxicant to control wild pigs (Sus scrofa), a destructive invasive species whose population growth is proving difficult to control through conventional management methods. Using a nationwide self-administered survey with 2,186 completed and returned questionnaires, we found that among six different lethal control methods, toxicant usage was the only method that a majority of respondents (51%) found to be unethical, with no significant differences between rural and urban respondents or between respondents from counties with wild pigs and counties where the species is absent. The …

Wild Pig Removal Reduces Pathogenic Bacteria In Low-Order Streams, Sara A. Bolds, B. Graeme Lockaby, Latif Kalin, Stephen S. Ditchkoff, Mark D. Smith, Kurt Vercauteren

USDA Wildlife Services: Staff Publications

Invasive wild pig populations have undergone enormous increases in the United States and particularly across the southern U.S. in recent years. High fecundity rates and abilities to adapt quickly to varied habitats have enabled pig populations to become entrenched and difficult to eliminate. The pigs cause many negative impacts on ecosystems including degradation of water quality through infusion of fecal contamination and other non-point source pollutants. Our goal was to determine the effects of pig removal on water quality in streams that were known to be significantly polluted by pig activity Bolds (J Environ Qual 50: 441–453, 2021). We compared …

Behavioral States In Space And Time: Understanding Landscape Use By An Invasive Mammal, Steven M. Gray, John M. Humphreys, Robert A. Montgomery, Dwayne R. Etter, Kurt C. Vercauteren, Daniel B. Kramer, Gary J. Roloff

USDA Wildlife Services: Staff Publications

Animal movement models can be used to understand species behavior and assist with implementation of management activities. We explored behavioral states of an invasive wild pig (Sus scrofa) population that recently colonized central Michigan, USA, 2014–2018. To quantify environmental factors related to wild pig movement ecology and spatio‐temporal landscape use, we predicted wild pig behavioral states relative to land cover type, landscape structure (i.e., edge and patch cohesion), and weather conditions. We used global positioning system (GPS)‐collars and monitored 8 wild pigs from 2014–2018. We fit local convex hulls and calculated movement metrics revealing 3 wild pig behavioral states (resting, …

Summer Habitat Use And Movements Of Invasive Wild Pigs (Sus Scrofa) In Canadian Agro-Ecosystems, Corey J. Kramer, Melanie R. Boudreau, Ryan S. Miller, Ryan Powers, Kurt C. Vercauteren, Ryan K. Brook

USDA Wildlife Services: Staff Publications

Resource selection informs understanding of a species’ ecology and is especially pertinent for invasive species. Since introduced to Canada, wild pigs (Sus scrofa Linnaeus, 1978) remain understudied despite recognized negative impacts on native and agricultural systems globally. Elsewhere in North America, pigs typically use forests and forage in agricultural crops. We hypothesized Canadian wild pigs would behave similarly, and using GPS locations from 15 individuals, we examined diel and seasonal resource selection and movement in the Canadian prairie region. Forests were predominately selected during the day, while corn (Zea mays L.), oilseeds, and wheat (Triticum aestivum L.) …

Towards A More Comprehensive Understanding Of Wild Pig (Sus Scrofa) Impacts On Agricultural Producers: Insights From A Texas Case Study, Keith M. Carlisle, Nicole Didero, Sophie Mckee, Julie Elser, Stephanie A. Shwiff

USDA Wildlife Services: Staff Publications

This research investigates the impacts of invasive wild pigs (Sus scrofa Linneaus) on agricultural producers in Texas, with the aim of identifying and describing all categories of wild pig impacts and quantifying the extent of producers’ over- or underestimation of their total wild pig-related costs in 2018, as compared to calculations based upon data subsequently provided by the producers about individual wild pig-related costs and losses. Based on interviews with 23 producers in 16 Texas counties, we identified more than 20 discrete categories of negative impacts and negligible positive impacts associated with wild pigs. Among them were categories that have …

Economic Estimates Of Wild Hog (Sus Scrofa) Damage And Control Among Young Forest Plantations In Alabama, Micah Fern, Rebecca Barlow, Chris Slootmaker, John Kush, Stephanie Shwiff, Larry Teeter, Jim Armstrong

USDA Wildlife Services: Staff Publications

Operating as ecological engineers, the increased distribution and abundance of wild hogs (Sus scrofa) has caused considerable socio-economic impacts. The international scope of economic research providing wild hog damage estimates are often confined to agricultural crops, while damage estimates among forest plantations are lacking. In Alabama, private landowners hold the majority of timberland acreage and are less equipped to absorb financial losses from wild hog damage than their industrial counterparts. A survey was conducted to estimate the economic impact of wild hogs, namely costs of damage and control, to privately owned forestlands. The survey was distributed in the …

Rooting Out Genetic Structure Of Invasive Wild Pigs In Texas, Anna M. Mangan, Antoinette J. Piaggio, Michael J. Bodenchuk, Courtney F. Pierce, Timothy J. Smyser

USDA Wildlife Services: Staff Publications

Invasive wild pigs (Sus scrofa), also called feral swine or wild hogs, are recognized as among the most destructive invasive species in the world. Throughout the United States, invasive wild pigs have expanded rapidly over the past 40 years with populations now established in 38 states. Of the estimated 6.9 million wild pigs distributed throughout the United States, Texas supports approximately 40% of the population and similarly bears disproportionate ecological and economic costs. Genetic analyses are an effective tool for understanding invasion pathways and tracking dispersal of invasive species such as wild pigs and have been used recently …

Wild Boar In Flanders, Belgium: (Dis)Agreements Between Key Stakeholders On Wild Boar Management Objectives, Actions, And Legal Provisions, Caroline Geeraerts, Anneleen Rutten, Emma Cartuyvels, Pieter Verschelde, Sander Devisscher, Francis Turkelboom, Paul Quataert, Jim Casaer

Human–Wildlife Interactions

Wild boar (Sus scrofa) reappeared in Flanders, Belgium in 2006 after more than half a century of absence. Besides being a native and highly valued game species in Europe, wild boar are also known to be responsible for car collisions, crop damage, disease transmission, and ecological damage at high densities. The management of wild boar therefore seeks to balance these positive and negative impacts. Given the highly fragmented landscape in Flanders and its multifunctional use, coexistence with wild boar is only possible through integrated management involving relevant stakeholder groups. However, to be successful, this requires that the management …

Does Hunting Affect The Behavior Of Wild Pigs?, Oliver Keuling, Giovanna Massei

Human–Wildlife Interactions

Wild boar and feral swine (Sus scrofa) numbers are growing worldwide. In parallel, their severe ecological and economic impacts are also increasing and include vehicle collisions, damage to crops and amenities, reduction in plant and animal abundance and richness, and transmission of diseases, the latter causing billions of U.S. dollars in losses to the livestock industry each year. Recreational hunters are the main cause of mortality for this species, and hunting has traditionally been the main method to contain populations of wild pigs. Hunting might affect the behavior of the species, which potentially can lead to these animals …

Considering The Wide World Of Wild Pig Management, John M. Tomeček

Human–Wildlife Interactions

This is the letter from John M. Tomeček, associate editor for the special issue on wild pigs in Human–Wildlife Interactions.

A Profile Of Wild Pig Hunters In Texas, Usa, Rachael L. Connally, Maureen G. Frank, Gary E. Briers, Nova J. Silvy, Keith M. Carlisle, John M. Tomeček

Human–Wildlife Interactions

Wild pigs (Sus scrofa) are a widespread exotic, invasive species that poses ecological, agricultural, and human health risks in invaded areas. Wildlife managers often manage wild pig abundance and expansion to mitigate these risks. The diversity of stakeholders involved in the issue of wild pig management complicates efforts to manage the species, and, to be successful, wildlife professionals should consider the human dimensions associated with wild pig management. The prevalence of privately owned lands in Texas, USA necessitates cooperation to enact effective management policies. In this study, we investigate the factors that affect a hunter’s likelihood to participate …