Feral swine, also referred to as wild pigs, wild boar, or feral hogs, are among the most destructive invasive mammals in North America. Descended from escaped domestic swine and introduced Eurasian wild boar, these animals now occupy large portions of the United States and are expanding in parts of Canada.

In the United States, the USDA APHIS documents widespread distribution across much of the country, with populations continuing to shift and expand. In Canada, invasive wild pigs have established in several provinces and remain a growing concern, particularly across the Prairie region.

Feral swine are highly adaptable and thrive in forests, wetlands, agricultural lands, rangelands, and peri urban areas. Their impacts cut across agriculture, natural resources, infrastructure, animal health, and public safety.

Expanding Impacts Across Sectors

Agriculture and Property

Feral swine cause extensive economic damage each year. They root through crop fields, consume and trample row crops, destroy hay bales, damage irrigation systems, and tear down fencing. Pastures can be rendered unusable by repeated soil disturbance, increasing costs for reseeding and restoration.

They also prey on young livestock such as lambs and goats and compete with cattle for forage. Feed contamination and infrastructure damage add to financial losses experienced by producers.

Natural Resources and Ecosystems

Feral swine significantly alter ecosystems. Their rooting behavior disturbs soil structure, increases erosion, and facilitates the establishment of invasive plants. In wetlands and riparian systems, wallowing destabilizes banks and increases sedimentation, degrading water quality.

They consume mast, roots, invertebrates, reptiles, amphibians, and ground nesting bird eggs. This feeding behavior reduces native wildlife populations and disrupts food webs. Sensitive habitats such as prairies, bottomland forests, and coastal marshes are particularly vulnerable.

Animal and Human Health

Feral swine carry and transmit numerous pathogens and parasites, including swine brucellosis, pseudorabies, and leptospirosis. These diseases threaten domestic livestock, wildlife, pets, and in some cases human health. As populations expand, so does the risk of disease transmission at the wildlife livestock interface.

They are also associated with vehicle collisions and aggressive encounters in certain areas, creating additional public safety concerns.

Identification and Field Signs

Feral swine vary widely in appearance, making identification challenging. Some resemble domestic pigs, while others retain the coarse hair and elongated snout typical of Eurasian wild boar.

Field signs include:

• Tracks that resemble deer but are rounder and wider, often with dewclaws visible in soft soils
• Extensive rooting damage where soil appears plowed or rototilled
• Wallowing depressions in muddy or wet areas
• Tubular scat containing grain, plant material, or animal remains

They often travel in family groups known as sounders.

Management and Control: A Coordinated Approach

There is no single solution to managing feral swine. Effective programs rely on coordinated, science based, landscape scale strategies.

Common management tools include:

Whole sounder trapping using corral traps and remote trigger systems to remove entire family groups at once. Partial removal often leads to rapid reproduction and rebound.

Ground based removal operations conducted by trained professionals.

Aerial removal operations in appropriate jurisdictions where terrain and population density require it.

Exclusion fencing to protect high value crops and sensitive habitats.

Biosecurity measures and vaccination programs to reduce disease risks to domestic livestock.

Regulatory frameworks and enforcement to prevent illegal transport, release, or intentional propagation.

Experience across North America has shown that recreational hunting alone is not an effective long term control strategy. Opportunistic hunting can disperse sounders, increase wariness, and in some cases create incentives to maintain populations. Fragmented removal efforts often undermine coordinated eradication strategies.

For these reasons, hunting regulations and control authorities differ significantly by state, province, and territory. In some jurisdictions, year round removal is permitted under specific guidelines. In others, methods are tightly regulated.

Before attempting any control action, landowners and individuals must consult their state, provincial, or territorial wildlife and agriculture agencies. Unauthorized trapping, transport, or release of feral swine is illegal in many areas and can significantly hinder eradication efforts.

National and Continental Leadership

Addressing feral swine requires strong cross jurisdictional collaboration.

In the United States, the USDA APHIS National Feral Swine Damage Management Program works to protect agricultural and natural resources, property, animal health, and human health and safety by managing damage caused by feral swine. This program supports surveillance, removal operations, disease monitoring, research, and partnerships with states, tribes, and local stakeholders.

Across Canada, the Canada’s Invasive Wild Pig Leadership Group was formed in 2023 to help implement Canada’s Invasive Wild Pig Strategy 2022 to 2032. This national group supports coordinated reporting, prevention, control, and eradication efforts across provinces and territories.

At a broader scale, collaborative efforts such as the North American Feral Swine Working Group bring together experts and agencies to share research, align strategies, and strengthen cross border cooperation.

Because feral swine populations do not recognize political boundaries, sustained coordination among federal, state, provincial, territorial, tribal, and local partners is essential.

What You Can Do

Early detection and reporting are critical components of feral swine management.

The Squeal on Pigs campaign provides a centralized reporting system to help agencies detect new populations quickly and coordinate response efforts. Reporting sightings with location details and photographs, when possible, supports data driven management decisions.

Individuals should not attempt independent trapping, relocation, or unauthorized control activities. These actions can disperse populations and may violate local laws.

Raising awareness also plays a vital role. NAISMA’s new Squeal on Pigs collection in the NAISMA Shop at shop.naisma.org helps amplify coordinated prevention messaging across North America.

Feral swine represent one of the most complex invasive species challenges on the continent. Through informed public engagement, regulatory compliance, and strong cross jurisdictional partnerships, we can reduce their impacts and support long term management and eradication efforts.

For more information on invasive species prevention and management, explore NAISMA’s Know Your Invasives campaign.