Local bird wars

Keeping birds away from planes is a constant battle at many airports, including Minneapolis-St. Paul International Airport, where wetlands and wildlife preserves border the runways.

Birds and planes collided more than 100 times at MSP last year, damaging many of the aircraft, said John Ostrom, manager of airside operations. Nationally, there were nearly 80,000 reported incidents of birds striking nonmilitary aircraft between 1990 and 2007, or about one strike for every 10,000 flights.

Airport officials attack the birds' food, perches and peace of mind:

• Kentucky bluegrass that geese love is out. Less appetizing alfalfa and clover mix is in.

• Trees where flocks like to gather and roost are eliminated and barbed wire keeps birds off utility poles.

• Mesh covers the airport's pond, making it a no-swim, no-feeding area.

• Radio-controlled propane cannons set off loud shotgun-like bangs and airport workers shoot handheld bangers and screamers to startle birds. A stuffed coyote and a stuffed fox are moved around the grounds to scare geese.

• Airport workers trap and relocate raptors. They also trapped the geese until the money ran out.

• Lethal measures are a last-resort step, Ostrom said, but there is zero tolerance for deer near runways, and birds that have become acclimated to the scare tactics are shot.

MARY LYNN SMITH