CHAMPAIGN, Ill. — From mid-November 2015 through February 2016, scientists used GPS transmitters to track the movements of Canada geese near Midway International Airport in Chicago. They discovered that – in the colder months, at least – some geese are hanging out on rooftops, in a rail yard and in a canal close to Midway’s runways. This behavior increases the danger of collisions between geese and airplanes, the researchers say.

The study is reported in the journal Human-Wildlife Interactions.