FAA statistics indicate that the number of aircraft bird strikes reported in the U.S. quadrupled from 1990 to 2007, rising from 1,738 per year to 7,439, These strikes caused 3,094 precautionary landings, 1,442 aborted takeoffs, 312 engine shutdowns and 1,162 minor negative effects, it said.

Worldwide, crashes of more than 25 large aircraft were caused by bird strikes since 1960, according to a published study by Dolbeer. In 23 of these incidents, the strike occurred below 400 feet. More than 219 people were killed and more than 200 aircraft destroyed in accidents attributed to bird strikes since 1988, Dolbeer and other researchers found.

In the U.S., most bird strikes happen between July and October, when bird populations are highest. But they can happen at any time of the year.

Using data from the FAA's National Wildlife Strike Database for Civil Aviation, he concluded that management of birds should focus on the airport environment. Most bird strikes happen on approach, less frequently on takeoff.

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