ALBANY, N.Y. -- The crows came in squawking, crowding treetops and leaving a mess below -- a jet-black air force invading the city for another night.
But this time Ken Preusser was there.
He blared a recorded call of a crow in trouble. That agitated the birds. Then he fired four flares into the evening sky with a sharp crack and a shrill whistle. That flushed them from the trees. Preusser, a federal wildlife biologist, jumped back into his truck to do it again.
"We're going to find them," he said.
This is the front line of the war on crows.
Preusser and a crew from the U.S. Department of Agriculture's Wildlife Services are patrolling downtown Albany armed with pyrotechnic pistols, bullhorns and a laser. It's part of a pilot program designed to harass crows out of winter roosting spots in three upstate cities.
The wildlife team was called to a commercial section of the state capital bedeviled for the last few winters by a nighttime roost of crows estimated at 20,000. Tenants complained about noise and droppings so profuse the ground under some trees appears frosted. Crows generally leave their winter roosts around March for more rural nesting territories.
"We were getting complaints about people having to walk to their cars with umbrellas," said Joe Giebelhaus, the city's solid waste manager.
In December, the USDA team harassed crows in Troy, then moved to Albany for two weeks in January. Plans for a harassment campaign in Utica were put off for a year after the crows left on their own. Under terms of the $5,000 contracts with the cities, about a half-dozen crow chasers wearing blaze-orange USDA vests employ amplified distress calls, lasers that project red dots in trees and noisy flares.
The same method, minus lasers, was used by the USDA in Pennsylvania, New Jersey and Connecticut. The idea is that this combination of light and sound works well to spook the birds.
The team starts around 4:30 p.m., when crows start massing on "staging area" trees. Only when it gets darker will crows gather in a central roosting spot.
While Preusser uses words like "smart" and "persistent" to describe crows, these are birds with a bad image. Crows are a portent of evil in literature, a flock of crows is called a "murder" and "eating crow" is a humiliating act.
Cornell University ornithologist Kevin McGowan has spent years studying crows and even getting friendly with them (unsalted peanuts in the shell seem to work).
"Crows are not evil and they are not purposely trying to torment you," he wrote on his Web site. "They are just being crows, trying to live their lives and feed their families."
Unfortunately, crows seem attracted to city lights, which can help the birds see predators coming.
Crow-busting strategies range from shotguns to helicopters. Results have been mixed. In the city of Auburn a few years ago, crows roosted in trees where big-eyed owl balloons were meant to scare them away.
Richard Chipman, the Wildlife Services director for New York, claims success so far with the method being used in Albany and Troy. A roost of 18,000 in Troy has been reduced by about 90 percent, he said, and they are getting similar results in Albany.
Chipman hopes the birds will settle in less populous spots near the Hudson River. But crews have already shooed crows from trees in other parts of the city, which could mean harassed birds are trying to make short hops.
"There is nothing that is going to stop these birds from coming together; that's just what crows do," McGowan said.
Giebelhaus said the growing number of crow complaints justified the effort. Preusser is aware of the potential problem, and the crew is patrolling an expanded area to make sure crows don't take hold elsewhere in the city.