LANCASTER, PA. -- Crows -- tens of thousands of pecking, squabbling crows -- flap in from the countryside every night and jam the trees, wires, roofs and parking lots around Lancaster's Park City Center mall.
In Hagerstown, Department of Public Works Manager Douglas H. Stull compares the mess beneath his city's crow roosts to the floor of a chicken house. It's also slippery when wet, which means it's no good for cars or pedestrians.
In Chatham, Ontario, east of Detroit, Mayor Bill Erikson has tried almost everything to drive off 30,000 crows. This year he's chosen shotguns.
Across the continent this winter, millions of crows are gathering in raucous nighttime roosts that can look like some sort of biblical plague. And exasperated urban residents are demanding action to end the noise, the droppings and the Hitchcockian creepiness of it all.
No one is sure why this once-rural phenomenon is happening more and more in towns and cities. Kevin McGowan, a crow researcher at the Cornell University Museum of Vertebrates, says crows may have gradually become more comfortable around humans. Once routinely shot by farmers, crows got some seasonal protection from the 1972 Migratory Bird Treaty. Urban settings preclude year-round shooting and also provide several degrees more warmth in winter.
"My favorite explanation has to do with the night-light hypothesis," McGowan says. "They're afraid of great horned owls, and owls definitely have an advantage in the dark." Cities and suburban malls offer plenty of light.
People also provide crows with an all-season smorgasbord of garbage, and parks and suburbs offer lots of large roosting trees. Big roosts can be found in many parts of the Baltimore region this winter, including a particularly large gathering at the Seton Business Park in Northwest Baltimore.
Why the crows evolved this roosting behavior is not well understood, McGowan says. Large numbers may offer protection from predators. The gathered birds may also exchange information on the whereabouts of scarce winter foods.
But McGowan thinks it's more about social interaction. All of the noisy calling and skirmishing could be the birds' way of testing their strength and readiness to breed and defend territory.
Crows might be more comfortable with people, but the reverse is rarely true. Big roosts bring trouble.
In Lancaster, the crows' persistent pecking at the rubber membrane that seals the Park City mall's roof has caused thousands of dollars in damage and leaks in at least 25 stores. Their feces foul cars and customers alike.
About 100,000 crows arrived in downtown Hagerstown in October. As they flew off each morning to forage, the city Public Works Department moved in with pressure washers to clean the sidewalks and sweepers to scrub the streets. Residents and car owners were on their own.
An attack with soap and water in the 1970s killed the birds by stripping their feathers of the oils they need to stay warm. But the decaying birds, feces and broken branches left a terrible mess.
This year, the department drove the roosts from the downtown area with volleys from propane cannons, a noxious grape spray and "bird screamer" fire crackers launched into the trees.
But "it's not the solution. We just keep moving them to different locations," Stull says.
In Chatham, Erikson won legislative support for his drive to shoot his town's crows. Bird lovers immediately branded him a murderer.
"We're not exterminating anything. We just want to move them," he told the local newspaper. "Killing and wounding a few birds gives these intelligent birds the message, and they say, 'Hey baby, we're out of here.' "
If people can clean up after cats, dogs and horses, why do so many find crows so intolerable?
"Superstition," says Steve Johnson, an Auburn, N.Y., county planner. He founded a Web site (www.savethecrows.org) two years ago after 75,000 crows wintering in Auburn triggered cries for their eradication.
"The crow's gotten a bad rap," he says. Crows have long been associated with death, perhaps because they eat carrion. To some traditional cultures, crows were gossips, messengers of death, bad omens.
Indians in the Northwest saw them as the divine deliverers of light and culture, the creators of wind and thunder. But other cultures branded them as thieves, adept at stealing grain and garden sprouts (hence the invention of scarecrows), songbird eggs and garbage.
Crows also catch bugs, mice and snakes, but they rarely catch a break. When goldfinches gather, it's termed a charm. But a bunch of crows is called a murder.
Dead crows in New York and Baltimore have been linked to the West Nile-like virus blamed for human encephalitis deaths in New York City last summer. But crows and people are both victims of the mosquito-borne virus.
The experts get calls every winter from people desperate for advice on how to get rid of crows. They often suggest noisemakers, used early and often.
In Lancaster, Park City operations manager Eugene S. Rutherford bought four $700 propane cannons and put them on the mall roof. They fire automatically, from dusk to dawn. Few people have complained about the noise, Rutherford says, and the crows now shun the roof.
They still mass nearby, however, and bomb the parking lots. "You can't take a step without stepping in it," he says. Some customers avoid the place in late afternoon. A few have asked the mall to pay for carwashes.
Rutherford is assembling four more cannons, and he and executives from nearby businesses met last week with public officials to plan a long-term campaign to drive the birds out of town. "It's become an expensive problem, and there has to be a resolution," Rutherford says.
McGowan is not so sure. "I have yet to hear of an actual effective solution," he says. Shooing crows from their winter roosts is like trying to get a wrinkle out of a carpet: "You can move it around, but you can't get it to go away."
He says people should accept the roosts as a force of nature, a glimpse of a time when vast flocks of birds once darkened the skies.
Crows are members of the corvidae family, which includes the much larger ravens and the smaller jays.
Maryland is host to ravens in its far-western counties and to two species of crows. The common crow, found statewide, has an adult wingspan of 35 inches, weighs about a pound and typically has a life span of 10 years.
The smaller fish crow, once found only around the Chesapeake Bay, has spread to all but the most western counties.
McGowan began studying crow behavior 12 years ago. He says they're more like monkeys and people than most birds. The young stay with their parents for as long as six years, learning and helping to rear their younger siblings.
"When you see a small flock of crows in the back yard, it's usually a family of crows. People tend to think of them as gangs, but they're not," he says.
Crows will try to protect each other by "mobbing" or ganging up on owls or hawks. Most intriguing, McGowan says, are the crows' shifting alliances. "They can be defending a territory with their parents against a brother for two years, then switch sides and defend the brother's territory against their parents."
There have even been reports of crows fashioning and using twig tools to forage for insects.
The big roosts will break up and vanish on their own in March. But hunters see nothing wrong with applying birdshot to the problem. Crows are fair game in Maryland from mid-August to mid-March, dawn to dusk, Wednesday through Saturday. There are no kill limits.
An estimated 2,900 hunters killed about 47,000 crows last year, according to a Maryland Department of Natural Resources survey.
"We're not even putting a small dent in the population," says Montgomery County crow hunter Burt Mullineaux, 43. But it's not for lack of trying.
Mullineaux says he and his hunting buddies go out several times a week during the season. They set up blinds, put out decoys, switch on recorded crow calls, puff cigars, sip tea and wait.
"A good day is anytime we get over 20 [birds]," he says. "One day we got 83 birds and we ran out of shells. And they were still coming in." Last year they shot 754 crows.
Mullineaux calls it "the most exciting hunting you can do."
Gordon L. Krause of Timonium is creator and "crowmaster" of a crow hunter's Web page called (www.clark.net/pub/glkrause/ crowhunt.htm). He says the sport "has all the aspects to it that waterfowl hunting does, with much more action."
Hunters like it because crows are everywhere and because landowners are more apt to welcome them. Crows don't have the appeal of deer.
Their culinary appeal is unsettled. Krause's Web site includes instructions for cleaning and preparing crow breasts, and such recipes as "Summer Crow Kabobs" and "Crow in a Blanket." He says the meat tastes a bit like duck.
Mullineaux scoffs. "Eating crow" has always been a metaphor for being forced to admit a mistake. "If I were that hungry," he says, "I'd be shooting something else."