DNRE Director Signs Order to Make Feral Swine Invasive Species

Contact: Mary Dettloff 517-335-3014

Agency: Natural Resources

Dec. 10, 2010

Department of Natural Resources and Environment Director Rebecca Humphries has signed an order to make feral swine and wild boar an invasive species in Michigan. Humphries gave the order an effective date of July 8, 2011, giving the state Legislature time to enact laws to provide regulations for facilities that currently provide wild boar breeding and hunting. If legislation is not passed to regulate the facilities, the invasive species order will go in to effect, making it illegal to possess wild boar in Michigan.

"Feral swine pose a significant risk to Michigan's wildlife, ecosystems and agricultural resources, and they are a serious disease threat to humans, wildlife and domesticated pigs," Humphries said. "I urge the Legislature to address this issue in 2011. Michigan is in a unique position to address this threat to our natural and agricultural resources by having our legal options aligned, but regulation is greatly needed for us to be effective."

Wild boar breeding and hunting in shooting facilities is unregulated in Michigan, and boars are not listed as a game species in the state. Wild boar are not native to the state of Michigan.

The order lists wild or feral boar/swine/hog, Old World swine, razorback, Eurasian wild boar and Russian wild boar as invasive species. The DNRE estimates that there are at least 65 swine hunting or breeding facilities in the state, and that a vast majority of the feral swine running at large in Michigan are animals that have escaped from hunting or breeding facilities.

A feral swine work group comprised of stakeholders including pork producers and wildlife and conservation organizations, and hunting and breeding facility representatives met over the last few months to make recommendations for regulations for wild boar breeding and shooting facilities, including fencing standards, biosecurity measures, methods of inventory, liability for escaped animals, indemnity, fees to support regulation and penalties for violation. Humphries has urged incoming legislative leaders to take up the recommendations in the form of legislation to regulate wild swine breeding and shooting facilities, and to place a moratorium on the establishment of any new swine breeding or shooting facilities.

Damage caused by invasive swine to important species and ecosystems has been documented in virtually every segment of their range in the United States. Feral swine are particularly disruptive of native wildlife, including many desirable game species in Michigan, such as white-tailed deer, pheasant, wild turkey and ruffed grouse. Feral swine compete with native wildlife for food, including hard and soft mast (acorns and berries), which are often vital for some wildlife species in the winter months.

The disease threat posed by invasive swine to human and animal health through the transmission of disease is significant, Humphries said. A few invasive swine borne diseases to which humans are susceptible include brucellosis, leptospirosis, salmonellosis, toxoplasmosis, sarcoptic mange, E. coli and trichinosis. Feral swine also carry several diseases that threaten livestock, including pseudorabies, swine brucellosis, tuberculosis, vesicular stomatis and classic swine fever.

Feral swine's rooting behavior degrades water quality by contributing to significant soil erosion, and through the introduction of bacteria, including coliform bacteria, into rivers and streams. Rooting behavior also destroys native plant communities.

Some estimates suggest that invasive swine damage to agricultural crops and the environment conservatively total $1.5 billion in the United States. As opportunistic feeders, feral swine consume a wide variety of crops, including corn, hay, small grains, vegetables, soybeans, tree fruits and berries. In some states, studies have shown that feral swine's rooting and wallowing behavior in agricultural fields can create holes that damage farming equipment and endanger operators.

Wildlife experts from Texas - considered the state with the largest feral swine population in the United States - presented information last year to the Michigan Natural Resources Commission about management problems with feral swine. Experts told the NRC that there are no practical or economical management techniques that can adequately control the spread and negative impact of feral swine. Through aggressive breeding and high adaptability, feral swine are quickly able to establish populations in a variety of climates and ecosystems, they said.

"The state lacks the financial and human resources needed to control this species," Humphries said. "Other states have spent millions of dollars on trapping, shooting and other measures to control feral swine, and have admitted it is a losing battle."

Feral swine have been sighted in nearly every county in Michigan. For information about the feral swine issue, please go to www.michigan.gov/feralswine.

The Department of Natural Resources and Environment is committed to the conservation, protection, management, and accessible use and enjoyment of the state's environment, natural resources, and related economic interests for current and future generations. Learn more at www.michigan.gov/dnre.