That's why the larger airport keeps a regularly updated wildlife management plan, striving to accommodate threatened species, such as the horned lark and savannah sparrow, while discouraging nuisance species.
"We have to cohabitate with the wildlife here, and we do the best we can," Pallanck said. "It's a gentle balance that the airport keeps."
Bert Marien, who retired a few years ago after 37 years with the FAA as a controller and supervisor in the Bradley tower, said that in the fall it is routine for the airport to broadcast a "notice to airmen" warning of migrating birds.
"They can make a mess of an engine," he said, "but most of the time, thank God, it's one engine, and they can fly quite well on one engine." The time of greatest hazard is on takeoff, just at the point at which a plane starts to raise its nose to become airborne, Marien said. If an engine ingests a bird and shuts down, the plane can easily lose control.
But engines are made to be tough. For decades, Pratt & Whitney has tested new engine designs by subjecting them to the sloppy bird-strike test. Store-bought chickens and turkeys are flung into the whirling turbofan blades to ensure that they will not cause a failure.
A rigorous test occurred in the skies over Chicago in October 2004, when an American Airlines MD-80 carrying 112 people encountered a flock of double-crested cormorants at about 3,000 feet. Six of the 5-pound birds were sucked into one Pratt & Whitney JT8D engine, causing a fire. But the plane was able to return to O'Hare International Airport and land safely.