Bird flu detected in Wisconsin's wild bird population

Wisconsin State Farmer
A bald eagle was among a handful of wild birds in Wisconsin testing positive for a highly pathogenic strain of avian influenza.

The Wisconsin Department of Natural Resources (DNR) confirmed that a highly pathogenic strain of avian influenza has been detected in wild birds found five counties. 

According to the agency, samples of the the EA H5 Avian Influenza, a strain that is highly pathogenic for poultry, were collected from a Cooper’s hawk and a bald eagle submitted from Dane County, a lesser scaup from Columbia County, a red-tailed hawk from Grant County, a Canada goose from Milwaukee County, and a trumpeter swan from Polk County.   

This announcement follows preliminary positive results found by the U.S. Geological Survey's National Wildlife Health Center and confirmed by the U.S. Department of Agriculture's National Veterinary Services Laboratory on March 30 and March 31.

The virus was first confirmed in Wisconsin on March 14, when the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) announced the detection of HPAI in domestic poultry in Jefferson County. As a result, nearly 3 million laying hens in the infected premises were depopulated and composted in a field near Palmyra.

The DNR continues to work closely with state and federal partners to monitor for this virus.

The strain of highly pathogenic avian influenza (HPAI) currently affecting the health of some domestic and wild North American birds is known as EA H5N1. It has caused disease in domestic and wild birds in multiple states since it was first detected in North America in December 2021.

The DNR asks the public to email or call with reports of waterfowl, waterbirds, raptors (especially bald eagles) and avian scavengers such as crows, ravens and gulls showing tremors, circling movement or holding their heads in an unusual position. These symptoms may be a sign of HPAI.

These reports can be made to the DNR Wildlife Hotline by emailing DNRWildlifeSwitchboard@wi.gov or by leaving a voicemail message for a return phone call at 608-267-0866.

Anyone who observes sick or dead birds should minimize contact with them. Do not touch dead birds or wildlife with your bare hands. If you have to touch a dead bird, wear gloves or use a plastic bag to put it in the garbage. Wash your hands with soap and water after handling and throw away any gloves.

Avian influenza is caused by a virus that is common in wild birds, especially waterfowl and shorebirds. There are many different subtypes of avian influenza, and most do not cause obvious signs of disease in wild birds. Waterfowl often carry avian influenza viruses naturally without causing disease, but there have been rare strains, such as EA H5N1 HPAI, that can cause disease in some wild birds or other animals. Whether a strain is classified as low or highly pathogenic depends on how lethal it is to domestic poultry.

In general, upland birds such as wild turkey have behaviors and prefer habitats that make them less likely to encounter avian influenza viruses in the wild. Spring turkey hunters can find safety and precautionary information on the USDA website. This strain of HPAI also does not pose a food safety risk; properly handling and cooking harvested birds to an internal temperature of 165°F kills the virus.

More information on Avian influenza viruses and the ongoing response to this HPAI strain can is available on the DNR's wildlife diseases webpage. The DNR will continue to update the website with any future HPAI findings in wild Wisconsin birds.