Feral Swine in Michigan - A Growing Problem
Like other Midwestern states, Michigan is experiencing a growing problem with feral or wild swine. Thirty years ago, there were no feral swine sightings reported in Michigan. By the end of 2011, more than 340 feral swine had been spotted in 72 of Michigan's 83 counties, and 286 have been reported killed. A sow can have two litters a year of four to six piglets. Based on their prolific breeding practices, it is estimated that feral swine in Michigan currently could number between 1,000 and 3,000.
Wild pigs or Russian boars (Sus scrofa) are not native to the United States. They were first introduced to the United States in 1539 by Spanish explorer Hernando DeSoto, who brought hogs to southwest Florida. Nearly 500 years later, the U.S. Department of Agriculture estimates there are at least 4 million feral swine nationwide causing hundreds of millions of dollars in damage each year to farms, residential areas, forests and the environment.
Feral swine in Michigan are a combination of Russian boars and escaped or neglected domestic pigs. Depending on ancestral lineage and cross-breeding among breeds, feral swine vary in appearance. Typical fur coloration for true Russian boar can be grey to dark brown to black, while domestic breeds can display a wider variety of colors with many defining patterns of striping or spots. Several generations of cross-breeding between domestic and Eurasian lineages can make the physical appearance of these animals drastically different within the same family unit. As with coloration, the size of mature adults can vary greatly depending on the bloodlines. In Michigan, adults typically range in size from 100-200 pounds, but larger specimens do occur.
Why Are Feral Swine a Problem?
Feral swine are a problem for two main reasons - they can host many parasites and diseases that threaten humans, domestic livestock and wildlife; and they can cause extensive damage to forests, agricultural lands and Michigan's water resources.
Feral swine have been known to carry several diseases and parasites, including hog cholera (classic swine fever), pseudorabies, brucellosis, tuberculosis, salmonellosis, anthrax, ticks, fleas, lice and various worms. Feral swine are highly mobile, making it easy for them to spread disease quickly in Michigan's wildlife and domestic livestock populations.
Feral swine carry several diseases that can infect humans including brucellosis, balantidiasis, leptospirosis, salmonellosis, toxoplasmosis, trichinosis, trichostrongylosis, sarcoptic mange, tuberculosis, tularemia, anthrax, rabies and plague.
Feral swine also are dangerous when cornered or threatened. They can become aggressive and charge and attack humans. They move with great speed and can cause serious injuries with their tusks.
Swine also compete for natural foods with wildlife, such as turkeys, deer and small game. Acorns are a preferred food for feral swine, just as they are for Michigan's native white-tailed deer population. Feral swine will eat almost anything, including dead animals and many forms of vegetation and tree seedlings. When there is a shortage of natural foods for them to consume, feral swine will forage on most agricultural crops and livestock feed. Feral swine will also eat small ground-nesting mammals and birds. And using their acute sense of smell, feral swine will find and eat young domestic livestock and poultry.
Feral swine also routinely engage in two types of behavior that are damaging to soils, crops and water - rooting and wallowing. Their rooting behavior, during which they dig for food below the soil surface, causes erosion, damages lawns and farm lands, and weakens plants and native vegetation. Wallowing behavior, during which feral swine seek out areas of shallow water to roll in mud, destroys small ponds and stream banks, which impacts water quality.
What is the Michigan DNR Doing About Feral Swine?
The DNR has declared Sus scrofa, one species of swine, an invasive species in Michigan. As such, possession of this species of swine is now prohibited in Michigan. This was a move by the Michigan DNR to join other states in the battle against feral swine, as well as to align with the National Invasive Species Laboratory's stance on feral swine. Hunting and breeding facilities in possession of Sus scrofa will face legal action by the state.
Active trapping of feral swine is being done throughout the state in cooperation with USDA-Wildlife Services and the Michigan Department of Agriculture. Any person who believes there might be feral swine on his/her property and would like to inquire about borrowing a trap should contact Nate Newman at USDA-Wildlife Services at 517-336-1928.
The DNR is an active member of the inter-agency Feral Swine Working Group formed by the Michigan Department of Agriculture and Rural Development. The working group is currently working on a feral swine control and eradication plan for Michigan.
What can you do?
Under Michigan law, any hunter with any valid Michigan hunting license can shoot feral swine on sight while hunting. Private property owners also may shoot any feral swine on their property and do not need to be in possession of a hunting license. If a hunter harvests a swine, he or she is encouraged to provide samples for disease testing by contacting USDA-Wildlife Services at 517-336-1928. Learn more about the rules for hunting or shooting feral swine in Michigan.
Report any sightings or harvesting of feral swine to Nate Newman at the USDA Wildlife Services Office in Okemos at 517-203-2696. Sightings, kills and damages can also be reported using this online form.