Geese pose danger at Chicago airport

Given the dangers that wildlife can pose to aviation, federal recommendations suggests a buffer zone around runways free of things can could attract animals. But at Midway Airport in Chicago, researchers found, that’s a challenge when it comes to Canada geese. In colder months, the geese spend time on rooftops, in a railyard and in a canal close to Midway, raising the danger of collisions between geese and planes.

“We knew there were lots of geese around the airport, and we had an idea of what habitats they were using,” TWS member Ryan Askren, a University of Illinois graduate student and lead author on the study published in Human-Wildlife Interactions, told the university news bureau.

From mid-November 2015 through February 2016, the research team used GPS transmitters to track the movements of 31 Canada geese (Branta canadensis) near the airport, collecting data on their altitude and position.

“What we didn’t understand before we started looking into it is that the geese are acting very oddly,” said Michael P. Ward, a University of Illinois professor of natural resources and environmental sciences and Illinois Natural History Survey avian ecologist. “Their behavior is different than what most wildlife biologists would think of as typical for geese.”

The researchers found that geese visited these sites often, sometimes crossing runway approaches to do so. Of the 3,008 goose movements they recorded, 821 came within 10,000 feet of airport runways and 399 intersected the flight paths of approaching and landing aircraft.

“I think the geese are on the rooftops because they don’t want to be disturbed,” Ward said. “No one’s jogging past them. No cars are honking at them. They can sit up there and conserve energy and not move.”

The canal offers another opportunity for the geese to avoid expending energy because it’s warmer than other waters, Ward said, and the birds appear to find spilled grain at the railyard.

Ward suspects the findings apply beyond Midway Airport.

“The behavior of the geese at Chicago is going to be similar to the geese around airports in Toronto, Minneapolis, Madison or Des Moines — any airport in the upper temperate region,” he said. “Wherever you go, these geese are adapting to humans and changing their behaviors to take advantage of any opportunities they have.”

The researchers suggest discouraging the geese from congregating in these areas.

“Make it so it’s not a hospitable place for the geese,” Ward said. “I realize the geese will probably cause a problem somewhere else, but they won’t be causing a problem for airplanes.”