Wild pigs, wild costs: the economic consequences of wild pig invasions in the United States

Abstract

BACKGROUND

Wild pigs (Sus scrofa), an invasive species in the United States, cause extensive ecological and economic harm, impacting agriculture, forests, ecosystems, water quality, property, and human health and safety. Despite the substantial economic impacts, existing nationwide monetary assessments of wild pig damage are outdated and lack modern scientific rigor.

RESULTS

By synthesizing data from scientific journals, this study inventories the scope of wild pig damage, highlights gaps in our understanding of the associated costs, and introduces a novel composite approach to visualizing them. Additionally, it provides an updated conservative estimate of the economic costs associated with wild pig damage in the U.S. by combining known costs with reasonable extrapolations. While our analysis indicates a minimum annual cost of US$3.4 billion associated with wild pig invasions in the U.S. — considering agriculture, health, the environment and property — the true economic impact is likely to be far greater and remains largely unknown.

CONCLUSION

The study underscores the urgent need for standardized damage assessment protocols and increased research investment to accurately quantify the full economic burden of wild pig invasion. These data are critical for informed policy decisions and optimized resource allocation in wild pig management. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Analysis reveals that wild pigs in the U.S. cause a minimum annual cost of US$3.4 billion, impacting agriculture, property and natural resources, highlighting the need for increased research and policy.

1. INTRODUCTION

Wild pigs (Sus scrofa), a non‐native and highly adaptable invasive species, have become a significant ecological and economic concern in the U.S. Initially introduced in the 1500s by European settlers and later supplemented by the Eurasian wild boar for sport hunting, wild pig populations have expanded rapidly across much of the country. ¹ Combined with a high reproductive rate, the species's ability to thrive in diverse environments has led to an exponential increase in the distribution and population abundance of wild pigs, currently estimated at >6 million. ¹ Invasive wild pigs are now present in 32 states and three territories, with the largest populations concentrated in the southeastern U.S. and California. The U.S. Department of Agriculture's National Feral Swine Damage Management Program (NFSDMP) has slowed their expansion. However, wild pigs remain one of the most destructive invasive species in the U.S. ²

The damage caused by wild pigs is multifaceted, affecting agriculture, forestry, native ecosystems, water quality, and even human health and safety. ² , ³ , ⁴ , ⁵ , ⁶ , ⁷ Wild pigs are notorious for their destructive rooting and wallowing behaviors, which disrupt soil structure, destroy crops, and damage infrastructure such as fences and irrigation systems. ⁸ They also pose a direct threat to native flora and fauna through predation, competition and habitat degradation, often leading to declines in vulnerable species and proliferation of other invasive species. ⁴ , ⁹ , ¹⁰ , ¹¹ , ¹² In addition to ecological and agricultural damage, wild pigs serve as reservoirs for diseases transmissible to livestock, wildlife, and humans, compounding their economic and public health impacts. ¹³ , ¹⁴ , ¹⁵ , ¹⁶

Accurate and comprehensive estimates of damage are essential for informing policy, prioritizing management efforts, and allocating resources effectively. Formal attempts to quantify the economic costs of wild pig presence in the U.S. began in the late 1990s. ⁵ The two most frequently referenced nationwide assessments of wild pig damage in the U.S. come from Pimentel's work in 2000 and 2007. The most commonly cited 2007 estimate places the combined cost of crop damage and control measures at US$1.5 billion. ¹⁷ This figure was calculated by assuming a wild pig population of 5 million and multiplying it by US$300 per pig in estimated damages and control costs, with the per‐pig figure based on informal consultations with field experts. Pimentel et al., ¹⁸ assigned annual environmental and crop damage at US$800 million, calculated separately from control costs. This calculation used a population estimate of 4 million wild pigs and assumed US$200 per pig in annual damage, again based on informal expert consultation. In 2020, the USDA began communicating that wild pigs cause an estimated US$2.5 billion in damages and control costs, ¹⁹ a number that is not supported by a single peer‐reviewed summary analysis such as the one presented here. Although now outdated and lacking the methodological rigor of current scientific standards, these assessments are still commonly cited in ongoing research and public information channels because updated estimates are lacking.

Despite growing awareness of the problem, estimates of the total economic cost of wild pig damage remain fragmented and localized. A comprehensive literature review by Didero et al. ⁵ examined all available studies that provided economic estimates of direct wild pig damage in the U.S. Their analysis revealed that creating a methodologically sound national estimate of the economic impact of wild pigs remained unfeasible because past and current studies often focus on specific sectors or regions, leaving a gap in understanding the comprehensive impact of this invasive species on a national scale.

Didero et al. ⁵ established six criteria for evaluating individual economic estimates that could make them usable to generate a composite estimate of the economic impact of wild pigs, and identified 40 publications and professional reports that met these standards. By synthesizing data from scientific journals, we inventoried the scope of wild pig damage, evaluated its distribution across sectors to identify gaps in our understanding of wild pig‐related costs and provided a novel visual representation of those gaps. Additionally, we updated and integrated existing data, combining known costs with reasonable extrapolations to establish a lower bound for the composite estimate of the costs imposed by wild pigs across the U.S. This approach aims to inform more targeted and effective management strategies to mitigate the impacts of wild pigs on U.S. landscapes and economies.

2. MATERIALS AND METHODS

2.1. Wild pig damage visualization charts

2.1.1. Literature review on wild pig impacts

An initial literature review was conducted to examine the range of resources reportedly impacted by wild pigs. This review used the database criteria established by VerCauteren et al. ²⁰ as a foundation. To populate this original database, studies were selected based on their measurement of direct or indirect damage caused by wild pigs. The search, conducted in Web of Science and Digital Commons in August 2023, excluded disease studies and reviews. Damage was defined as impacts on various categories, including crops, natural resources, and public recreation. This process resulted in 209 unique studies meeting the inclusion criteria. This original database was supplemented with a search for more recent publications using the same query: (boar OR pig OR hog OR pigs OR scrofa) AND (feral OR wild OR invasi*) AND (damag* OR depredat* OR rooting OR wallow* OR graz* OR digging OR disturbance OR ‘ecological impact’ OR predate* OR vehicle OR collision), and focusing only on studies measuring direct or indirect damage from wild pigs, with a publication range from September 2023 to August 2024. As our interests include the economic burden posed by transmissible diseases carried by wild pigs, we have included all disease studies fitting the selection criteria and highlighted these in the Supporting Information.

2.1.2. Layout of the charts

This initial literature review identified various resource categories susceptible to negative impacts from wild pigs. The resource categories were classified into three primary groups: (1) agriculture, including resources grown for sale in the U.S. (e.g. crops and horticulture, livestock and fisheries), (2) private & public property, including residential property, vehicles, and drains and levees, and (3) environmental and natural resources, including natural waters, native species, and forests.

The impacts were then categorized into five cost types: (1) Direct Resource Damage—this includes instances where wild pigs directly harm resources, such as rooting crops or livestock predation; (2) Property Damage—this encompasses damage caused by wild pigs to structures, fences, or other man‐made assets; (3) Control Costs—this category includes expenses incurred to manage wild pig populations, such as the cost of implementing removal programs or constructing fences; (4) Indirect Costs—this includes costs associated with lost opportunities, such as the inability to utilize land owing to wild pig presence, as well as costs related to replanting resources or additional cost at harvest; and (5) Disease Transmission Costs—this includes the costs associated with the transmission of diseases from wild pigs to resources (e.g. livestock) or to humans who come into contact with those resources.

We created a visualization matrix for each of the three primary resource groups to present this information graphically. The columns in each matrix represent the different categories of resources, and the rows represent the five types of cost.

2.1.3. Resource category monetary value

Where obtainable, the annual monetary value of each resource category is presented beneath its title to underscore its significance to the U.S. The values shown represent the total estimated value of production for each resource within states in the contiguous U.S. known to have a wild pig presence in 2024. Table 1 enumerates all resources for which an estimable total annual production value could be determined, along with the data source and reference year. The monetary values of the resources featured in Figs 3, 4, 5 were updated to reflect their 2024 equivalent based on the annual average inflation rate. ²¹

Table 1.

Sources for the total monetary resource values

Resource category	Value source	Year
Agriculture
Grains	USDA NASS 22	2022
Other field crops	USDA NASS 22	2022
Vegetables	USDA NASS 22	2022
Fruits and nuts	USDA NASS 22	2022
Horticulture	USDA NASS 22	2022
Pasture	USDA NASS 22	2022
Livestock	USDA NASS 22	2022
Commercial fisheries	NOAA 23	2022
Public and private property
Golf courses	Hirsch 24	2023

Figure 3.

Annual resource values represent the total annual value of the resource within states with wild pig presence in the continental United States in 2024 USD. Values within a wild pig icon represent the annual estimated cost of damage to this resource by wild pigs. A filled wild pig icon represents that damage costs to this resource and damage category are known or estimable. White wild pig icons represent damage costs that exist but are unknown.

Figure 4.

Annual resource values represent the total annual value of the resource within states with wild pig presence in the continental United States in 2024 USD. Values within a wild pig icon represent the annual estimated cost of damage to this resource by wild pigs. A filled wild pig icon represents that damage costs to this resource and damage category are known or estimable. White wild pig icons represent damage costs that exist but are unknown.

Figure 5.

Annual resource values represent the total annual value of the resource within states with wild pig presence in the continental United States in 2024 USD. Values within a wild pig icon represent the annual estimated cost of damage to this resource by wild pigs. A filled wild pig icon represents that damage costs to this resource and damage category are known or estimable. White wild pig icons represent damage costs that exist but are unknown.

2.1.4. Wild pig icons

The presence of a stylized wild pig icon within a cell of the matrix indicates that a particular type of cost was associated with the corresponding resource category in the literature on wild pig impacts. A white icon indicates that the cost type has been identified but its monetary value for the U.S. is currently unknown. A colored icon signifies an estimated value for that cost type in the U.S. (see Section 2.3).

2.2. Wild pig abundance

In order to estimate the abundance of wild pigs in the U.S., we used a method similar to the methodology used by Lewis et al. ¹ We generated state‐ and county‐level estimates of wild pig population abundance for 2022 using two national‐scale datasets describing the expected population density of wild pigs ²⁵ and the known distribution of wild pigs ²⁶ in the U.S.

The expected population density of wild pigs (animals km⁻²) reported in Lewis et al. ²⁵ uses the relationship among density and biotic and abiotic factors to predict wild pig population density across the global range of wild pigs (see Lewis et al. ²⁵ for complete details of this approach). The density estimates from Lewis et al. ²⁵ have been used to estimate population abundance at multiple scales including for states and have been shown to align well with population abundance estimates from other sources. ¹

The known distribution of wild pigs in the United States has been recorded since 1982 by the Southeastern Cooperative Wildlife Disease Study and Animal and Plant Health Inspection Service (APHIS) Wildlife Services (WS) through a consistent and national effort. ²⁶ Wild pig populations are included in these distribution data if wild pigs are observed to be present for ≥2 consecutive years and evidence of reproduction has been observed. Populations are removed from the distribution data when state and federal agencies determined that wild pigs no longer occupy an area. These are the best available data describing wild pig distribution over time in the United States and have been used to estimate wild pig probability of occurrence, ²⁷ the potential range expansion of wild pigs, ²⁸ , ²⁹ , ³⁰ potential risks for disease transmission, ¹⁶ potential impacts on imperiled species ²⁹ and the potential population size of wild pigs. ¹

In order to estimate the abundance of wild pigs by state or county in the U.S., we intersected the Lewis et al. ²⁵ predictions of expected population density, which are available as a raster with a 1‐km² resolution, and the associated lower and upper bounds of the 95% prediction interval with boundaries defining the known presence of wild pigs in the U.S. We then estimated abundance within each state by summing density predictions for each 1‐km² cell within each state using,

$$N_j=\sum \text{wild}\mathrm{pig}{\text{density}}_{\mathit{ij}}*{\text{cell proportion}}_{\mathit{ij}}*{\text{presence}}_{\mathit{ij}}$$ (1)

where $i$ is all 1 km² cell in state or county $j$, wild pig density is the expected population density for cell $i$ in state or county $j$, cell proportion is the proportion of cell $i$ in state or county $j$, and boundary is a binary indicator for cell $i$ in state or county $j$ describing the presence (1) or absence (0) of wild pigs.

Figure 1 displays wild pig abundance by state in 2020.

Figure 1.

Estimated relative wild pig population by state (2020).

2.3. State‐level cost estimates of wild pig impacts

2.3.1. Literature review on state‐level cost estimates of wild pig impacts

A second literature review was completed to gather publications which presented cost estimates that met criteria necessary for modeling costs across the U.S. This literature review utilized the database created by Didero et al. (2023), ⁵ inventorying all literature providing economic estimates of direct damage caused by wild pigs in the U.S. through 2020. An additional query was completed for the years 2020–2024 to capture recent publications using the statement: TI = (Wild pig OR feral swine OR feral pig OR feral hog OR sus scrofa) AND AB = (economic OR estimate OR cost OR dollar OR USD) AND (impact OR damage OR destruction OR depredation OR consumption OR disease) pubrange = 1/2020–2/2024. This compilation of articles was then compared against the Invacost database; ³¹ any unique articles in the Invacost database were added before filtering for selection criteria.

Subsequent to the collection of a complete compilation of articles, duplicates were screened and removed along with those that did not meet the relevance criteria. These exclusion criteria include any article that: do not relate to economics, do not provide a damage estimate, do not provide a novel damage estimate (e.g. citing another study's estimates), or provide estimates outside of the U.S. Following this screening process, the database was filtered for articles that met the eligibility requirements for extrapolation. Articles that provided no resource‐specific damage estimates and articles which provided no state‐level estimates were excluded. Figure 2 displays a breakdown of this selection process.

Figure 2.

Flowchart of monetary estimate article selection.

2.3.2. State‐resource‐specific wild pig densities

For states lacking complete cost data, models were developed to estimate costs, provided that sufficient data existed. To achieve this, a wild pig density specific to each resource within each state was constructed using county‐level data on resource presence from the 2022 Census of Agriculture ²² and wild pig populations by county (see Section 2.1). This estimate [Eqn (2)] was calculated using the total pig population in state $i$, in counties that produce resource $j$, divided by the total area are of counties in state $i$ which produce resource $j$.

$$\begin{array}{c}{\text{density}}_{\mathit{ij}}=\frac{\text{wild}{\text{pigs}}_{\mathit{ij}}}{\text{total}{\text{resource area}}_{\mathit{ij}}}\end{array}$$ (2)

2.3.3. Production loss extrapolation for crops

The influence of state‐resource‐specific wild pig density and resource category on crop‐specific damage ratios was analyzed within each state. A quasi‐binomial generalized linear model (GLM), implemented with the glm function from the R stats package, ³¹ , ³² , ³³ , ³⁴ , ³⁵ was used because the ratios range from 0 to 1. Linear, logarithmic and quadratic forms of density were tested. Gini index ranking was employed to compare models, as AIC is not applicable to quasi‐binomial models. ³⁶ , ³⁷ , ³⁸ This was implemented in R using the Gini function in the desctools package. ³⁹ , ⁴⁰ , ⁴¹ Gini index ranking identified that a linear functional form on wild pig density provided the most accurate predictions.

The model was applied to predict damage ratios for any state‐resource combinations lacking observed data, and total value of the resource $j$ lost to wild pig damage in state $i$ was then estimated by multiplying the total production value of resource $j$ in state $i$ by the damage ratio of resource $j$ in state $i$ [shown in Eqn (3)].

$$\begin{array}{c}\text{total}{\text{resource damage}}_{\mathit{ij}}={\text{total production}}_{\mathit{ij}}*{\text{damage ratio}}_{\mathit{ij}}\end{array}$$ (3)

2.3.4. Other cost‐type extrapolation for crops

The logarithm of property damage (using the logarithm of the number of operations as a predictor) and the logarithm of control and other costs (using the logarithm of acreage as a predictor) were modeled at the state and resource level. State‐resource‐specific wild pig density also was included in the models (see Section 2.3.2).

2.3.5. Extrapolation for other resource categories

For resource categories other than crops, when cost data was only available for a subset of states, the costs to the remaining states were extrapolated by assuming that costs were both proportional to the wild pig population and total resource value for each state. The ratio between the costs for the states with known damage estimates and the product of wild pig population and total resource value for these states was calculated and applied to the product of wild pig population and total resource value for the states with missing cost data. Table 2 provides a breakdown of the sources utilized to determine the proportion of resource value attributable to each state.

Table 2.

Sources for state‐level resource share

Resource category	Source
Agriculture
Livestock	NASS 22
Public and private property
Residential property	U.S. Census Bureau 42
Golf courses	World Population Review 43
Cemeteries	Zelinsky 44
Pets	World Population Review 43
Environmental and natural resources
Natural waters	USGS 45
Hunting leases	Realtree 46
Wildlife food plots	Realtree 46

3. RESULTS

The literature review on wild pig impacts resulted in 211 additional publications not previously cited by VerCauteren et al. ²⁰ Sub‐setting to studies which measured direct or indirect damage from wild pigs and excluding disease studies reduced the count of additional studies to 13. These are presented in Table S1.

All papers identified by the literature review on state‐level cost estimates of wild pig impacts are listed in Table 3. The economic impact of wild pigs on the U.S., encompassing agriculture, health, the environment, and property, is ≥US$3.4 billion annually. However, this figure likely underestimates the total cost, which remains largely unknown.

Table 3.

Wild pig state‐level cost estimate literature

Resource	Damage estimate source
Agriculture
Grains	Anderson et al. 47 , McKee et al., 6 Ober et al., 48 Tanger et al. 49
Other field crops	Anderson, 47 McKee, 50 McKee et al., 6 Ober et al., 48 Tanger et al. 49
Vegetables	McKee et al. 50
Fruits and nuts (including berries)	McKee et al. 50
Pasture	McKee et al. 51
Livestock	McKee et al. 51
Commercial fisheries	Poudyal et al. 52 , Tanger et al. 49
Public and private property
Vehicles	McKee et al. 53
Drains & levees	Poudyal et al. 52 , Tanger et al. 49
Residential property	Poudyal et al. 52
Landscapes	Tanger et al. 49
Golf courses	McKee et al. 54
Cemeteries	McKee et al. 54
Pets	Tanger et al. 49
Environmental & natural resources
Wildlife food plots	Poudyal et al., 52 Tanger et al. 49
Hunting leases	Poudyal et al., 52 Tanger et al. 49
Natural waters	Poudyal et al., 52 Tanger et al. 49

3.1. Agriculture

The wild pig visualization matrix pertaining to agriculture is represented in Fig. 3. Our analysis estimates that wild pigs cost the U.S. agricultural sector at least US$3.2 billion annually.

3.1.1. Grains and other field crops

Grain crops include corn, wheat, soybeans, rice, barley, and other oilseeds, drybeans and drypeas. ⁶ , ²² The value of grains produced in states with active wild pig populations make up >60% of the value of all grains produced within the U.S. (≈US$109 billion). ²² Other field crops, as identified by the 2022 Census of Agriculture, ²² include hay, peanuts, sugarcane, tobacco and cotton.

Wild pigs damage grain and field crops directly via consumption (or depredation) of the crop as well as rooting and trampling crop land. ⁶ , ⁴⁷ , ⁵⁶ Grain crops account for the highest amount of known wild pig damage in the U.S. Extrapolating to all states with pig populations, wild pigs cause an estimated US$1,056.8 million direct damage to grain crops alone, per year. Furthermore, yearly property damage and control costs incurred by grain operations owing to wild pigs are estimated at US$137.3 million and US$257.2 million, respectively. In addition to these damages, wild pig presence requires producers to spend time and financial resources on replanting and harvesting, and prevents them from growing a preferred crop or otherwise using their land for more profitable purposes at the opportunity cost of other productive activities. ⁶ , ⁵⁷ These costs totaled ≈US$194.2 million yearly for grain producers. Although wild pigs pose a recognized risk for zoonotic disease transmission through direct contact and meat consumption, ⁵⁸ , ⁵⁹ there is currently no scientific evidence supporting the transmission of diseases to humans through the consumption of grains contaminated by wild pigs.

Direct damage to field crops, like grain crops, is primarily driven by wild pigs rooting soil and directly consuming the crop itself. ⁸ , ⁵⁵ We estimate that the annual cost of wild pig damage to field crops in the U.S. is ≈US$498.1 million.

3.1.2. Fruits and vegetables

Wild pigs primarily cause damage by eating or trampling fruit and vegetable crops. ⁶ , ⁴⁷ , ⁵⁵ , ⁵⁶ We estimate that the annual cost of destruction to fruit and vegetable crops is ≈US$147.9 million and US$50.2 million, respectively. ⁴⁹ Fruit and vegetables often utilize drip irrigation systems which may easily be damaged by trampling and rooting of wild pigs, suggesting that property damage costs for these crops may be a significant unrepresented cost in our estimates. ⁵⁵ Wild pigs also can transmit diseases to certain vegetable and fruit crops, particularly those consumed raw. For example, a 2006 E. coli outbreak, resulting in >200 illnesses and three deaths, was traced to wild pigs contaminating spinach fields. Although this link is well‐documented, the annual impact of such contamination events and associated costs remains unknown. ⁶⁰

3.1.3. Horticulture and commercial forestry

Our review found no state‐level damage estimates for horticulture or commercial forestry that could be used to extrapolate national impacts. However, it is recognized that wild pigs harm these industries, primarily through rooting and predation on saplings, particularly pines. ³ , ⁶⁰ Girdling and tusk damage to mature trees also are significant concerns. ³ , ⁶⁰ While comprehensive economic data are scarce, studies indicate that a single wild pig can destroy numerous planted pine saplings—at a rate of up to six per min. ⁶¹

3.1.4. Livestock and pasture

Wild pigs threaten livestock production in a variety of ways. They are opportunistic feeders, readily consuming livestock feed when available, and they also prey on young or vulnerable animals such as calves and lambs. ⁵¹ , ⁶² , ⁶³ , ⁶⁴ We estimate the annual impact of wild pig depredation on livestock to be ≈US$81.9 million. In addition to these behaviors, wild pigs are known disease vectors for livestock, transmitting diseases such as brucellosis and leptospirosis. These diseases lead to increased veterinary costs, lower reproduction potential, and even death of domestic livestock species. ⁸ , ⁵⁶ Yearly estimates of the cost of wild pig‐borne disease among livestock are ≈US$10.8 million.

Wild pigs are responsible for significant damage to livestock properties where they destroy fences and equipment. ⁸ , ⁵⁰ The property damage and control costs incurred by livestock producers as a result of wild pigs far surpasses the cost of predation at an estimated US$409.1 million and US$290.2 million, respectively. ⁵¹

Given the critical role of pastureland in agricultural livestock production, the significant damage that wild pigs inflict upon it warrants attention. Wild pigs damage pastures through trampling and rooting productive forage as well as wallowing in drainage areas. ⁸ , ⁴⁹ , ⁵⁵ These behaviors reduce drought resistance, reduce the production potential of land, and increase erosion. ⁶³ Direct damage to pastureland in the U.S. is estimated at US$123.9 million yearly. ⁵¹ Property and control costs of wild pigs in pastureland are captured in livestock costs.

3.1.5. Commercial fisheries

There are currently no state‐wide estimates of wild pig damage to fisheries that fit our criteria for extrapolation; however, wild pigs may impact fishery operations in a number of ways. Their wallowing behavior near these aquatic ecosystems leads to soil erosion, which in turn promotes the growth of invasive plants and disrupts the pH levels of ponds and other native water sources. ⁶⁵ , ⁶⁶ Furthermore, wild pig waste introduces contaminants such as E. coli into these environments, potentially harming both aquatic wildlife and humans. ⁵⁵ , ⁶⁵

3.2. Private and public property

The wild pig visualization matrix pertaining to private and public property is represented in Fig. 4.

3.2.1. Vehicles

The ever‐expanding presence of wild pig populations combined with the infrastructure growth of U.S. roadways have significantly escalated wildlife vehicle collisions involving wild pigs. In 2022, there were an estimated 16,714 vehicle collisions involving wild pigs. ⁵³ These collisions cause massive damage to personal property as well as potentially fatal injuries to drivers and passengers involved. According to vehicle insurance data, the total repair costs of vehicle–pig collisions across the U.S. in 2022 is estimated at US$110.3 million. ⁵³ Importantly, this estimate only represents the economic costs of repairs and does not include the medical costs incurred as a result of these collisions. Wild pig incursions also pose a collision hazard to aircrafts, necessitating private management efforts at airports to ensure safety. ⁶⁶ , ⁶⁷

3.2.2. Drains/levees

Wild pigs can inflict damage to irrigation systems ranging from minor, yet costly, nuisances to potentially catastrophic failures. As with fisheries, their presence near water sources raises concerns about contamination. ⁵⁵ , ⁶⁶ Furthermore, their rooting activity poses a risk to the structural integrity of levees, potentially leading to flooding. ⁸ Research on the economic impact of this damage to drains and levees is limited, with no current state‐wide estimates available for damage to public drains/levees. Damage to private drains and levees used for agriculture are captured in the property costs estimates for grains and livestock.

3.2.3. Residential property

Wild pigs can cause significant damage to residential property. Although interactions with residential areas are most common in rural settings, suburban areas also are vulnerable. ⁶¹ Wild pigs readily breach fences and other barriers intended to keep wildlife separate from humans. Once inside, they frequently damage irrigation systems, flower beds, landscaping and outdoor furniture. ⁶¹ , ⁶⁸ Based on available data, we estimate the annual cost of wild pig damage to residential properties at ≈US$17.6 million. ⁵²

3.2.4. Golf courses and cemeteries

Golf courses and cemeteries account for a significant portion of the U.S. turf grass industry. These properties attract the presence of wild pigs because the irrigation required to nourish the turf maintains a moist environment. ⁵⁴ Wild pig trampling, rooting, and wallowing behaviors destroy turf, irrigation systems, and even headstones. Additionally, pigs are adept at destroying fences and other exclusion measures designed to keep wildlife out. The only current estimate of wild pig damage to these properties comes from McKee et al. ⁵⁴ where 175 cemeteries and 389 golf courses across Texas were sent surveys aiming to assess damage from wild pigs. Extrapolating McKee et al.'s ⁵⁴ costs to the entire U.S., we estimate that the annual cost imposed by wild pigs for golf courses and cemeteries is US$0.7 million and US$3.4 million, respectively. Although property damage, replanting and control costs are included in these estimates, there is currently no estimate on the opportunity costs imposed by wild pigs on these properties.

3.2.5. Pets

Although mostly herbivorous, wild pigs are opportunistic and are known to prey upon smaller and often weaker animals. ⁸ , ⁶¹ In rural settings, much of the costs imposed by the predation of wild pigs on kept animals are captured under livestock. ⁶¹ , ⁶³ Beyond livestock impacts, wild pigs pose a serious threat to working and hunting dogs which are often used in managing this invasive species. ⁶⁹ , ⁷⁰ While no economic valuations currently exist for wild pig impacts on hunting dogs, injuries from these interactions are common among working dogs, although they are typically nonfatal. ⁶⁹ , ⁷⁰ , ⁷¹

Wild pigs attacking pets in urban areas tends to be rare and mainly a result of the animal feeling threatened; these attacks commonly result in large injuries such as puncture wounds. ⁸ , ⁷⁰ , ⁷¹ , ⁷² The current best estimate of the annual cost that feral swine impose on pets within the U.S. comes from a study in Louisiana. ⁴⁹ Extrapolating from this study, we estimate this total yearly cost at ≈US$0.8 million.

3.3. Environmental and natural resources

The wild pig visualization matrix pertaining to environmental and natural resources is represented in Fig. 5.

3.3.1. Wetlands, forests and other natural habitats

Wild pigs cause significant and extensive damage to natural habitats through rooting, trampling and wallowing behaviors. ⁷³ , ⁷⁴ , ⁷⁵ , ⁷⁶ They consistently damage globally imperiled wetland plant communities as well, including herbaceous seepage slopes, wet pine savannas and wet grasslands. ⁷⁶ Researchers are developing rapid assessment frameworks to quantify and economically value wild pig damage in wetlands. ⁷³

Wild pigs cause significant damage to young forest plantations, particularly during the seedling stage. They uproot seedlings and eat the roots of newly planted pines and hardwoods, frequently leading to unsuccessful forest regeneration. ⁷⁷ Effective management strategies, including regular monitoring and targeted control measures, are crucial for protecting sensitive habitats from wild pig impact. ⁷⁴ , ⁷⁶

3.3.2. Native species

Wild pigs inflict considerable harm on native plant and animal life. Plants that evolved without the presence of these invasive swine are especially susceptible to their destructive rooting and trampling, which decimates native species and fosters the proliferation of invasive flora. ⁸ , ⁶⁵ Moreover, wild pigs affect small animals through predation, competition, and habitat destruction. They also adversely impact avian species, and consume reptiles and amphibians. ⁷⁸ Finally, these omnivorous wild pigs compete for resources with a variety of native animals, including ungulates, rodents, and scavengers. ⁸⁰ , ⁸¹ , ⁸² The extensive damage that wild pigs inflict on native species represents a substantial but often overlooked economic burden.

3.3.3. Natural waters

Riparian ecosystems (stream side) present along natural waterways are particularly vulnerable and affected by the presence of wild pigs. Riparian vegetation serves as filtration systems for these waterways, but rooting and wallowing destroys natural vegetation and erodes stream banks, impacting downstream water quality. ⁶¹ , ⁸³ In addition to impacting the natural filtration mechanisms of these ecosystems, wild pigs introduce pathogens, further diminishing water quality. ⁵⁵ , ⁶⁵ , ⁸² A Study from Alabama found that observed waterways with wild pig populations nearby had E. coli. levels >40‐fold higher than similar national forest waterways which lacked nearby wild pig populations. ⁸² We estimate the yearly economic burden of wild pigs to these waterways at ≈US$4.6 million.

3.3.4. Wildlife food plots and hunting leases

Wild pigs are often classified as invasive ecosystem engineers. ⁸³ , ⁸⁴ Their impact on natural resources extends beyond damage and leads to the alteration of species composition among native flora and, consequently, native wildlife. ⁷⁸ , ⁷⁹ Competition for scarce food sources such as edible mast crops, and reduction in native, palatable foliage caused by rooting and trampling is associated with reduced native vertebrate populations in wild pig present areas. ⁷⁹ , ⁸⁰ We estimate the annual economic impact of these behaviors in the U.S. on wildlife food plots and hunting leases to be ≈US$29.2 million and US$8.1 million respectively. ⁴⁹ , ⁵²

4. DISCUSSION

Through a synthesis of existing literature detailing the wide array of resources affected by wild pigs and their economic costs, this research provides the first comprehensive understanding of the damage they inflict across the U.S. The study estimates a minimum nation‐wide cost of US$3.4 billion, encompassing impacts on agriculture, health, the environment and property—a figure significantly (>2‐fold) higher than the commonly referenced US$1.5 billion estimate from 2007. ¹⁷ This substantial increase was primarily driven by the agricultural estimate. These findings highlight the considerable economic burden, and the far‐reaching environmental and societal implications of this invasive species.

This study provides a foundational composite estimate, yet it also highlights significant gaps in the current understanding of the costs wild pigs inflict on the U.S. The most critical unaddressed areas include: estimating damages to wetlands, forests and natural habitats; depredation of native species; private control costs; and opportunity costs. The true economic impact of wild pig invasions is likely to be far greater and remains largely unknown. Future research should focus on standardizing methodologies for valuing nonmarket resources and assessing damage, as well as expanding data collection efforts to sectors for which damage information is still lacking (e.g. Beane et al ⁸⁵ ). The most robust studies should meet at least the following six criteria outlined in Table 1 of Didero et al. ⁵ : (1) Research methods for quantifying and valuing damage are vetted and clearly detailed; (2) the study sample or population is described; (3) damage units relative to the study sample or population are quantified and clear; (4) damage is classified using the ‘3D framework’ (destruction, depredation, disease) as thoroughly as possible; (5) a wild pig density (head/unit area) or a suitable proxy that can be applied to the study area; and (6) the currency estimate includes the year it pertains to. These criteria are essential not only for deriving a robust monetary value for reporting and communicating the context of the damage, but also for enabling long‐term monitoring of damages and costs.

Most economic estimates used for the cost analysis are derived from state‐level surveys of crop and livestock producers, which capture only the private costs incurred by landowners. Many states also have programs and initiatives in place to manage wild pig populations. ⁸⁶ , ⁸⁷  In addition to state‐level efforts, the U.S. Department of Agriculture (USDA) plays a significant role in feral swine management through the NFSDMP, that provides resources and expertise to states and landowners, upon request. Moreover, the role of wild pigs as reservoirs of diseases further complicates the management landscape, as it intersects with public health and livestock industries. The NFSDMP conducts surveillance for wild pig diseases. ⁸⁸ The funding for these management and surveillance programs is not included in our estimate.

Finally, surveillance efforts focus primarily on the early detection of diseases that are not currently in the U.S., including classical swine fever, African swine fever, and foot and mouth disease. Each of these foreign animal diseases has the potential to cause significant harm to the U.S. economy through morbidity, mortality, decreases in consumer demand and a moratorium on international trade. ⁸⁷ The co‐occurrence of domestic and wild suids significantly would complicate management of these diseases given the potential for wild populations to serve as persistent sources for spillover. ⁸⁹ , ⁹⁰

CONFLICT OF INTEREST

The authors have no conflict of interests that might be perceived to influence the results and/or discussion reported in this paper.

FUNDING INFORMATION

This research was supported by the U.S. Department of Agriculture, Animal and Plant Health Inspection Service and the National Feral Swine Program. Mention of commercial products does not represent an endorsement by the US government. The findings and conclusions in this publication are those of the authors and should not be construed to represent any official USDA or US Government determination or policy.

Supporting information

Data S1: Supporting Information.

Data S2: Supporting Information.

DATA AVAILABILITY STATEMENT

Data sharing not applicable to this article as no datasets were generated or analysed during the current study.