Authorities suspect they may have been poisoned.
On Tuesday, six dead geese were discovered at McKinley Park on the Southwest Side. Chicago Police News Affairs says an additional ten geese were found in the park Wednesday.
"Anytime you find numbers in that level of dead animals, you have to wonder what is going on," said Field Museum bird expert David Willard. "One of your first thoughts would be is that they could have been poisoned."
"We're taking it seriously. We're trying to identify if there is any concern for the public," said Sharie Travis of Chicago Animal Care and Control. "There was concern yesterday that there was a theory that it could be poisoning. Today, there is some discussion about maybe it is a... bird disease."
More dead geese were found not far away at McGuane Park, and at Henry C. Palmisano Nature Park. Chicago's animal control department has several of the geese and they are testing tissue to determine what killed them. On Tuesday, they suspected poisoning.
"There's a lot of maintenance of the lawns in these various places that does include chemicals," said Willard. "This is total speculation on my part - but it's conceivable to me that some chemical that's being used in those parks is lethal to geese."
Willard says that Canada Geese are abundant in Chicago, especially at this time of the year. It is highly unusual, though, to find so many of them dead in just a couple of days.
"We are working with the Illinois Department of Natural Resources. We are working with the county. We're working with the USDA and other agencies, the Chicago Department of Public Health, to find out exactly how these birds died so that we know what the risk is," said Travis.
Animal Care and Control says they have been notified of at least 20 dead geese. They say people should not walk their dogs in the park where the geese were found until they release their results.