Considering the Wide World of Wild Pig Management

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

Did Predator Control Go to the Dogs? A 40-year Retrospective

In 1980, Green and Woodruff published an article entitled, “Is Predator Control Going to the Dogs?” At that time, the use of Livestock Guardian Dogs (hereafter LGDs) was a relatively new wildlife damage management tool in North America. Although this tool passed the test of time in its point of origin, early North American adopters stepped into a brave new world with little to guide them. In the modern world, knowledge of methods and means of wildlife damage management exists in written texts, films, and other guides. For LGDs, however, such materials did not exist 40 years ago. Over the last few decades, ecologists worldwide began a rigorous program to evaluate the use and effects of LGDs on livestock and natural systems. We now endeavor to update and evaluate the state of LGDs as a wildlife damage management tool in the course of this special issue, asking whether or not predator control went to the dogs

The influence of income and loss on hunters\u27 attitudes towards wild pigs and their management

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 to theTexas A&M Human Dimensions of Wild Pigs Survey. Attitudes towards wild pigs varied significantly based on landownership status and whether land was used for agricultural practices. In addition, landowners who received income from wild pigs on their land considered government or agency hunting to be a less acceptable method of control than those who did not generate such income. However, effect sizes for all our results were small (η2 ≤ 0.05, Adj. R2 ≤ 0.09, and McFadden\u27s R2 ≤ 0.07) and, across all groups, attitudes towards wild pigs were negative. Few respondents (3.91% of landowners, 0.56% of non‐landowners) reported generating income from wild pigs, and reported losses were approximately 4 times greater than income. Supplemental file attached

Factors Influencing the Movement of Livestock Guardian Dogs in the Edwards Plateau of Texas: Implications for Efficacy, Behavior, and Territoriality

Livestock guardian dog (Canis lupus familiaris; LGD) breeds of domestic dog worldwide provide a degree of control over predation losses. The application of LGDs as a wildlife damage management tool evolved as a cultural practice in the Old World. In the 1970s, this tool emerged in North America. Despite several decades of science and application, gaps still exist in our knowledge regarding applications for LGDs. From February 2016 to November 2017, we deployed global positioning system transmitters on 4 LGDs on a 20-km2 ranch in Menard County, Texas, USA operated by Texas A&M AgriLife Research to investigate their fine scale movement and activity patterns, site fidelity to livestock management units (i.e., pastures), and fidelity to anthropogenic features, such as feed and water locations. The LGDs remained within study site boundaries for 90% of the study period. Additionally, daily activity patterns differed for dogs associated primarily with sheep (Ovis aries) and goats (Capra aegagrus hircus). All of the LGDs we studied were active throughout the 24-hour day. We determined that feed and water locations concentrated LGD activity to an extent, likely reflecting a livestock affinity for water sources, and provide an additional method by which to distribute them over the landscape. Our results, based on a small sample size, suggest that LGDs may provide effective association with livestock management areas, maintain a high fidelity to area perimeter boundaries, and distribute themselves across the area of use

Cost–Benefit Analysis of Coyote Removal as a Management Option in Texas Cattle Ranching

The monetary value of livestock losses attributed to coyote (Canis latrans) predation in North America has increased during the past 20 years. In Texas, USA alone in 2011, these loses were estimated at $6.9 million. To mitigate coyote-related livestock losses, several lethal and nonlethal control methods have been developed. However, there remains a need for better information to guide management decisions regarding cost-effective predator control strategies for livestock production systems. We acquired data, which was used in the model, from published literature from 1960 to present day, subject matter experts, and anecdotal information on coyote ecology. We developed a systems dynamics simulation model to evaluate the economic impact of coyote control on an average-sized cattle (Bos spp.) operation (1,000 ha) for a conceptual 10-year period in Texas. We conducted a sensitivity analyses to validate the model and identify the most sensitive parameters. We tested 88 scenarios using common coyote management methods (i.e., aerial gunning, M-44 devices, snares, livestock guard animals (LGAs), calling and shooting, and foothold traps), combinations of multiple management methods, and number of applications per year (once per year, twice per year, continuous). Several management methods were cost effective at reducing calf predation when applied sparingly and under assumptions of skillful and dedicated application of coyote control methods. The most cost-effective method of coyote control to reduce calf depredation was the combined use of snares and LGAs. When applied 1 month prior to the primary calving month, the snare/LGA combination showed an 81% decrease in overall costs of calf loss and predator management during the 10-year period, respectively. Cost effectiveness of methods deteriorated as the number of applications per year increased. While these are useful results, the intangible values of coyotes through grazing benefits (i.e., fewer prey species such as lagomorphs on the landscape to compete for forage with cattle) and ecological benefits (i.e., mitigation of meso-predator release) were not included in the model. However, these benefits should be considered by ranchers before implementing lethal coyote management

A Profile of Wild Pig Hunters in Texas, USA

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 in wild pig hunting. Multiple factors affect participation in wild pig hunting activities. We found that participation in other types of big game hunting increased the likelihood of participation in wild pig hunting and that wild pig hunting does not deter individuals from participating in other types of hunting activities. Additionally, hunters’ attitudes toward wild pigs are important in determining the likelihood of participation in wild pig hunting. Finally, our results suggest that hunters are largely uninformed about wild pigs and do not hold the same perceptions, values, or tolerance levels of the species. The diversity of preferences among wild pig hunters necessitates that wildlife managers consider the desires of the public as well as natural resource needs in creating socially acceptable management plans for the species

Hunter Motivations and Use of Wild Pigs in Texas, USA

Wild pigs (Sus scrofa) are a widespread exotic, invasive species that pose ecological, agricultural, and human health risks in their invaded range. Wildlife managers must manage wild pig abundance and range 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 must 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 impact of hunter motivations on wild pig harvest quantity. Motivations driving wild pig hunting are diverse. While the majority of wild pig hunters in Texas are motivated by trophy value, meat-motivated hunters harvest more wild pigs per day afield. Wildlife managers should develop plans that include various management techniques to control wild pig population growth and damage. Education and outreach will continue to be important for involving private landowners in effective wild pig management

Characteristics of Hunter Harvested Montezuma Quail Wings and Implications for Molt Phenology

We obtained 1,899 hunter-harvested Montezuma quail (Cyrtonyx montezumae) wings from southeastern Arizona, USA, from the 2008–2009 hunting season. We determined age and sex based on plumage characteristics for 98.2% (1,864) of the original sample. One-way analysis of variance (ANOVA) of wing-chord length found differences (P \u3c 0.001) based on sex, but not age, with mean (± standard error) male wing chord (113.76 ± 0.15 mm) longer than mean female wing chord (111.03 ± 0.13 mm). Mean male and female wing-chord lengths from our study population were 6.8% and 7.7% shorter, respectively, than previously reported in the literature. We additionally calculated a complete prebasic molt cycle of 177 days based on previously reported preformative molt patterns. The primary benefits of our results are: 1) a more accurate sex-based wing-chord length based on a large sample size, 2) a method to back-calculate molt onset dates for hunter harvested after hatch year Montezuma quail, and 3) a potential means to model the influence of precipitation on population dynamics of Montezuma quail

A Critical Look at Wild Pig Elimination: Myths and Facts

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 measure of management success, and in some cases the rationale for support or lack thereof for operational management programs. For example, some stakeholders believe that if a wild pig elimination program does not remove 70% of the population annually across the state, then it is not being effective. These strong and widespread anecdotal beliefs may actually impede management progress. Herein, we describe the likely origin of the 70% parameter and the science to support why this metric measuring success of an elimination program is inaccurate

Texas Hunters’ Perceptions Regarding the Acceptability of Toxicants to Control Wild Pig Populations

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 pig toxicant, the sociodemographic and other factors most closely associated with acceptability of such a toxicant, and the specific concerns that underlie hunters’ positions on the use of such a toxicant. We received 37,317 completed responses to an online, self-administered survey. Respondents were divided over the use of a toxicant, with 43% finding a toxicant acceptable, 18% neutral, and 39% finding a toxicant unacceptable. The factor most closely associated with acceptance of a wild pig toxicant was respondents’ desired wild pig population size in Texas (χ2 = 3,657.7, P \u3c 0.001, V = 0.26), with 70% of respondents who preferred that wild pigs be completely removed from Texas finding the use of a toxicant to be acceptable, compared to 14% of respondents who preferred that wild pig populations increase or stay the same. The most commonly raised concerns in connection with toxicant usage were potential negative impacts to nontarget animals (33%) and negative impacts to human health (24%). Our research suggests that while achieving a consensus among Texas hunters on toxicant usage is unrealistic, building majority support may be possible if the identified concerns are sufficiently addressed in product development and outreach