UPDATE: The USDA has officially declared that the birds tested from Baker’s Lake died of avian influenza.

The large and varied bird population at Baker’s Lake forest preserve is suffering from a presumed outbreak of H5 avian influenza, according to laboratory results from University of Illinois Urbana-Champaign. Further testing is being conducted by the federal government, which provides the only declaration of incidences of avian influenza. The Forest Preserves of Cook County estimates that more than 200 birds have died in the past week.

Forest Preserves wildlife biologists presented seven cormorants for necropsy and testing to state pathologists on Thursday, April 7 after observing numerous dead birds at Baker’s Lake the evening before. Staff are monitoring other Forest Preserves’ locations for indications of avian influenza but have no evidence of the disease at any other Forest Preserves sites at this time.  

Many native and migratory birds nest and feed at Baker’s Lake, including at an island rookery. Because of the nature of the local bird population, the avian influenza impact to date has only been observed among waterfowl and water birds. Because passerines—perching birds such as songbirds, sparrows and finches—have not been affected, the Forest Preserves does not recommend the removal of birdfeeders to limit the transmission of the disease. 

According to the Centers for Disease Control and Prevention, the H5 bird flu virus poses a low risk to the public. Visitors to the Forest Preserves should not touch or interact with a sick or dead bird, or any animal. If you observe more than one dead bird at a location, please notify the Forest Preserves at ResourceManagement.FPCC@cookcountyil.gov.