(January 2025): Highly pathogenic avian influenza virus strain remains active in Wisconsin and across much of the United States. USDA APHIS is continuing to track avian influenza detections here.

A Canada Goose swims in a pond. Mallards are swimming behind it. — *Canada Goose and Mallards (photo via Pixabay).*

AVIAN INFLUENZA in WISCONSIN

The Wisconsin DNR announced in March 2022 that highly pathogenic avian influenza virus (also known as HPAI or EA H5 Avian Influenza) had been detected in wild waterfowl and raptors. The outbreak seriously impacted state breeding populations of Caspian Terns and Bald Eagles, and was linked to cases in wild foxes, bobcats, fishers, skunks, and otters.

HPAI has remained active in Wisconsin since. In December 2024, the virus was detected in geese and swans in Dane, Brown, and Wood counties, in addition to commercial poultry operations in Barron and Kenosha counties.

Black-capped Chickadee perched on the side of a feeder. — *Black-capped Chickadee on a feeder (photo via Pixabay).*

WHAT ABOUT BIRD FEEDERS?

Many of you have been asking us about bird feeders, which we recommended people take down during 2021’s outbreak of a mystery illness that primarily impacted songbirds. The HPAI outbreak is different than the mystery illness.

Southern Wisconsin Bird Alliance has carefully examined the available data on HPAI. At this time, we are not recommending the removal of songbird feeders and baths, except under certain conditions. We DO advise you to take down your bird feeders and baths if:

Your feeders are visited by birds like waterfowl, raptors, or other species that are highly susceptible to HPAI.
You keep domestic poultry or live in close proximity to a poultry farm.

We will continue to follow this very closely and update our recommendations accordingly. As always, we recommend that anyone with bird feeders continues to follow responsible protocol by cleaning feeders and baths at least once per week. Wear disposable gloves, empty, then clean with a 10% bleach solution (one part bleach mixed with nine parts water). Rinse thoroughly with water and allow to air dry completely (in the sun if possible) before filling with fresh seed or water.

Read on to learn more about HPAI and what you can do to prevent its spread.

What is HPAI?

HPAI is a deadly viral disease that infects the respiratory and gastrointestinal tracts of birds. It has significantly affected wild birds and domestic poultry (chickens, turkeys, ducks), and farms may suffer rapid spread and high mortality rates. HPAI is also zoonotic virus, meaning that it can cross species boundaries and be transmitted to people and other animals.

What species are affected by hpai?

The virus most commonly affects domestic and wild birds. Currently, the wild birds most affected seem to be the following:

Waterfowl (such as ducks, geese, and swans)
Waterbirds (such as loons, grebes, terns, gulls, coots, pelicans, and shorebirds)
Wading birds (such as egrets, herons, and cranes)
Raptors (especially Bald Eagles and those which predate the above species)
Other avian scavengers (such as crows, magpies, and ravens)

Since the outbreak began, the virus has also been detected in other species that predate or come into close contact with the affected bird species. This includes wildlife, like red foxes, but also domestic animals, like pet/feral cats. Since April 2024, 16 states have also reported infections in dairy cattle herds (as of 1/27/2025, this does not include Wisconsin). There have also been cases of HPAI in humans who have had contact with sick birds or dairy cattle.

What should I watch for in wild birds?

According to the Wisconsin DNR, avian species may contract, shed, and spread the avian influenza virus at a rapid rate without showing symptoms of the disease. If they do show symptoms, common symptoms include:

Poor coordination and neurologic symptoms
Nasal discharge, coughing, and sneezing
Lack of energy or appetite, diarrhea
Purple discoloration or swelling of on the body
Misshapen eggs
Sudden death

What should I do?

If you are a birder, please be vigilant. This virus is hardy and can be spread easily via vehicles, birding equipment, and more. If visiting a wetland area, bring footwear to change into before getting out of your vehicle and change out of as you get back in. Disinfect footwear and equipment before using again.

According to the CDC, the current health risk to the general public is low, and transmission from person-to-person has not been identified. However, simple precautions should be taken to reduce or minimize the risks of infection:

Do not handle sick or dead birds, and keep people and pets away.
If you are birding or walking through areas that put you close to waterfowl or walking through waterfowl feces, change and disinfect your shoes before wearing them at a new site. Bring a spray bottle with 10% bleach solution (one part bleach mixed with nine parts water) to spray your gear and allow to air dry.
Wash hands thoroughly with soap and water after contact with a wild bird or contaminated surfaces. Flu viruses are inactivated by common disinfectants including detergents, 10% bleach solution, and alcohol.
Those who keep domestic bird flocks of any size should review the APHIS Defend the Flock program.
Reduce the possibility of transmission to domestic cats by keeping them indoors.
Cook all meat, including wild birds and poultry thoroughly to a temperature of 165° F to kill organisms and parasites.
Hunters should sanitize all tools and surfaces when handling, cleaning, and preparing wild birds.
Report sick or dead wild birds by filling out the Wisconsin DNR reporting form. You may also contact the DNR Wildlife Switchboard:
Email: DNRWildlifeSwitchboard@wi.gov
Phone: 608-267-0866 (leave a voicemail message for a return phone call)