Aviation securityStructures Near Airports Increase Risk of Airplane-Goose Collisions

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.

Illinois says that the Federal Aviation Administration recommends that – depending on the type of aircraft served – airports maintain a 5,000- to 10,000-foot buffer around runways that is free from wildlife attractants. But the study revealed that the geese are using man-made structures inside the buffer zone at Midway Airport.  

The researchers placed neck-collar-mounted GPS transmitters on 31 geese captured in parks from within a 7.5-mile zone around Midway Airport. The team collected hourly data on each bird’s altitude and position over four months.

Study lead author Ryan Askren, a graduate student at the University of Illinois, said it was important to follow the birds’ precise movements from site to site.

“We knew there were lots of geese around the airport, and we had an idea of what habitats they were using,” he said. But knowing how the birds moved – and at what altitude while in proximity to runways – was critical to understanding the risk to airplanes.

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

Early in this study, co-author Brett Dorak, a graduate student in Ward’s lab at the time, used transmitters to track Canada geese using rooftops and rail yards in the vicinity of the airport. He found that some of the geese visited those sites quite often. Flight paths of the geese traveling between these locales and parks and other open spaces nearby showed that the geese were often crossing the runway approaches.

“Of the 3,008 goose movements we recorded, 821 came within 10,000 feet of airport runways,” Askren said. “Of those, 399 intersected the flight paths of approaching and landing aircraft.”