SOUTH PORTLAND (AP) – Residents living near the Portland International Jetport can rest easier knowing that the gunfire they’ve been hearing is just an attempt by airport employees to scare away birds.

Police dispatched officers on Tuesday and Wednesday to look into reports of guns being discharged. The officers didn’t hear anything but later learned that airport workers were firing shotgun blanks.

The airport is trying to frighten away flocks that try to nest in tall grass near the two runways. “We have an issue with nesting birds particularly in the spring and summer because we’re surrounded by wetlands,” Portland Transportation Director Jeff Monroe said.

The fear is that entire flocks will rise from the grass as planes are taking off or landing. The birds can be sucked into jet engines and cause damage to airplane instruments and wingflaps.

Monroe recalled one incident three years ago when a Delta MD-80 taking off for Cincinnati passed through a flock of birds, damaging the radar dome and the windshield and forcing the jet to return to the airport.

Airport workers use two devices to encourage the birds to nest elsewhere. First, workers will set off a “twizzler” which emits a high-pitched whine akin to some fireworks used in Fourth of July celebrations. If that doesn’t work, employees shoot blanks from a shotgun.

Monroe said the workers do not shoot the birds. The noise alone displaces the birds, which then settle elsewhere, out of harm’s way.

Jetport operations workers check along the runway in the morning and throughout the day looking for flocks of birds that have settled nearby.

Controllers in the air traffic control tower also will notify ground crews when they spot a concentration of doves, Canada geese or other migratory birds.

AP-ES-05-15-03 0922EDT