A sudden and alarming outbreak of avian flu has left thousands of birds dead along Chicago’s beaches over the weekend. The deaths, mostly among red-breasted mergansers, have local bird enthusiasts worried due to concerns about a highly contagious H5N1 avian influenza outbreak.
According to Edward Warden, president of the Chicago Ornithological Society, images of dead waterfowl surfaced in birder forums and local monitoring groups, showing birds displaying abnormal behaviors. The sudden deaths are believed to stem from the highly contagious H5N1 avian flu outbreak.
The Illinois Department of Natural Resources has documented 144 cases of suspected avian flu across Illinois since Dec. 3, with a figure consistent with the hundreds of calls received by the Chicago Bird Collision Monitors. However, the dead mergansers recovered over the weekend have not been tested for avian flu and are therefore not confirmed cases.
Bird enthusiasts express concern about the virus’s spread, citing a higher-than-normal number of deaths among waterfowl this winter. “This is obviously way more than normal,” said Warden. The Chicago Bird Collision Monitors reported observing ducks displaying symptoms of illness during a Calumet River trip last month.
The avian flu appears to be escalating this year, with 87,300 birds affected in Illinois’ poultry industry since November. H5N1 is caused by the avian influenza A virus, which spreads globally among birds and can affect mammals like dairy cows, goats, pigs, and cats.
While there have been no confirmed human cases in Chicago or Illinois, experts advise people to take precautions. They can identify sick birds by looking for signs such as glazed eyes and shivering bodies, or if they are not moving and closer to shore or on land. The public is urged to report dead birds to an Illinois Department of Natural Resources wildlife biologist.
Source: https://blockclubchicago.org/2025/02/04/bird-flu-suspected-in-deaths-of-hundreds-of-ducks-found-in-around-lake-michigan