FERAL SWINE:

Impacts to 

Native Wildlife

What Can I Do?

Feral swine cause problems by damaging native 

ecosystems, preying on or competing with native 

wildlife, and spreading diseases.

• If you live in a State with no or low populations 

of feral swine, report any sightings, signs, or 

damage to the wildlife or agriculture officials in 

your State.

• Do not relocate feral swine to new areas or 

transport them to other States.

• Share the knowledge, spread the word, and 

discourage the transportation and spread of 

feral swine. 

What Is Being Done? 

Wildlife Services, part of the U.S. Department 

of Agriculture’s (USDA) Animal and Plant Health 

Inspection Service (APHIS), is conducting a 

national program to manage the damage caused 

by invasive feral swine through the National Feral 

Swine Damage Management Program. Our main 

goal with this program is to protect agricultural 

and natural resources, property, animal health, and 

human health and safety by reducing feral swine 

damage in the United States and its territories. 

Through a coordinated national effort, we work 

closely with partners at the Federal, State, and 

local levels to address the extensive damage 

caused by feral swine populations.

Animal and Plant Health Inspection Service

Large sounder wallowing, damaging habitat

Want To Learn More?

Call the USDA-APHIS Wildlife Services program in 

your State at 1-866-4-USDA-WS or go to www.

aphis.usda.gov/wildlife-damage/stopferalswine

to learn more about the problems caused by 

this invasive animal, as well as to seek advice and 

assistance in dealing with feral swine.

The U.S. Department of Agriculture is an equal

opportunity provider, employer, and lender.

Program Aid No. 2195d 

Revised May 2020
What Are Feral Swine 

and Where Are They 

Found? 

Feral swine were first introduced to the United 

States by Spanish explorers in the 1500s. Natural 

breeding, new introductions, and relocation by 

humans caused populations to expand rapidly. 

Feral swine can thrive in almost any habitat, 

mature at 6–8 months of age, and a single sow 

can have up to 2 litters of 4–12 piglets a year, 

making them a prime example of an invasive 

species. Feral swine populations encroach 

on many important wildlife habitats, causing 

significant damages to these ecosystems. Feral 

swine also damage the quality of lands for 

ranching, recreation, and other uses. Habitats and 

ecosystems impacted by feral swine populations 

are of incredible importance to many threatened 

and endangered species, further jeopardizing 

these already vulnerable species. Feral swine also 

live in habitats of importance to deer, turkeys, 

upland birds, and other valuable game species, 

which poses a risk of economic loss to businesses 

that depend on these valuable game species. 

How Do Feral Swine 

Impact Native Wildlife 

and Plants? 

Feral swine are one of the world’s worst invasive 

species. It has been estimated that feral swine have 

played a role in the decline of nearly 300 native plants 

and animals in the United States alone. Over 250 of 

these species are threatened or endangered, while 

others are valuable game animals or important native 

forage plants. Feral swine impact native species and 

ecosystems in a variety of ways, from direct predation 

or competition to altering ecosystems and destroying 

habitats through their destructive foraging, trampling, 

and wallowing behaviors.

DIRECT IMPACTS

Feral swine are 

opportunistic 

omnivores that prey

on the nests, eggs, 

and young of native 

wildlife such as 

sea turtles, prairie 

chickens, wild turkeys, 

alligators, and upland 

game birds. They 

also prey on both the young and adults of small 

vertebrate species such as rodents, amphibians, and 

reptiles like the endangered dunes sagebrush lizard. 

They root out and eat amphibians and invertebrates 

from ground cover, threatening species such as the 

flatwoods salamander. They tear up grasses, shrubs, 

and seedlings, killing sensitive plants such as Mead’s 

milkweed. Feral swine compete with native wildlife 

for many key resources. Their keen sense of smell, 

tenacious feeding behaviors, and ability to digest 

a variety of foods makes them serious competitors 

with native wildlife for nutritional resources. They 

consume the fruits, nuts, and seeds of trees, thereby 

competing with deer, turkeys, black bears, and small 

mammals such as squirrels. Feral swine are aggressive 

animals and will actively chase off other species. Their 

generally disruptive behavior, particularly around 

feeding or wallowing areas, will disturb and scatter 

other animals. For example, the endangered Houston 

toad will avoid breeding in ponds the feral swine use 

for wallowing. 

INDIRECT IMPACTS

Feral swine are ecosystem engineers, which means 

they can change their environment. Feral swine can 

have an immense impact on the vegetation and 

soils throughout their range. They are changing the 

distribution of plants in many grasslands and forests 

and are destroying habitat for rare insects such as the 

Hine’s emerald dragonfly. High consumption of nuts 

and seeds, along with rooting and rubbing behaviors, 

can even impact forest growth, particularly in oak 

forests. Feral swine aid in the spread of invasive 

plant species, such as strawberry guava, by 

disturbing the native plants and transporting seeds 

of invasive weeds. They alter runoff and water 

quality in wetland environments, through rooting 

and wallowing, which impacts fish species such 

as the Oskaloosa darter. Feral swine carry over 30 

pathogens and 40 parasites, many of which can 

infect wildlife. 

Feral swine rooting protected sea turtle nest to eat eggs 

Feral swine preying on ground-nesting bird eggs 

Young wildlife, like fawns, are particularly vulnerable to feral swine predation. 

FAR-REACHING IMPACTS

Feral swine eat mostly vegetation, but recent 

research shows they will prey on native wildlife. 

Feral swine have been known to consume the eggs 

of ground-nesting birds, reptiles, or amphibians; 

the young of large mammals such as deer; and 

both the young and adults of small mammals, 

reptiles, and amphibians.

Habitat change, through their wallowing, rooting, 

and feeding, is the most widespread and harmful 

impact of feral swine to native wildlife. Feral swine 

alter wetland and riparian habitats, pollute water, 

change vegetation composition and distribution, 

and displace native wildlife across the United States.