A large number of red-breasted mergansers have been found dead or sick in Chicago and surrounding areas, with officials suspecting a highly contagious bird flu as the cause. The Chicago Bird Collision Monitors reported finding “large numbers” of mergansers along the shores from Hyde Park to Wilmette.
According to Annette Prince, organization director, two concentrations of sick mergansers were found Saturday at North Avenue Beach and Oak Street Beach, with around 200-300 infected birds reported between Friday and Sunday. This is the first time such a large number of mergansers has been suspected of bird flu infections, which have been on the rise in waterfowl and other birds throughout Illinois and the US.
Prince noted that most of the dead mergansers were found with symptoms consistent with bird flu, including weakness, inability to stand, tremors, green diarrhea, and respiratory problems. Volunteers are picking up sick birds to prevent further transmission.
The Centers for Disease Control and Prevention (CDC) has reported 67 cases of human bird flu, mostly in people who work with livestock or poultry, with one reported death. Over 11,000 wild birds have been infected across the country since the outbreak started in 2022, and backyard and commercial poultry have suffered greatly, with nearly 150 million birds affected.
The disease is forcing farmers to slaughter millions of chickens a month, pushing US egg prices over double from summer 2023. The surge in bird flu cases has raised concerns about its spread to other species.
Source: https://chicago.suntimes.com/news/2025/02/02/several-hundred-ducks-found-dead-from-suspected-bird-flu-along-lake-michigan