Some farmers enforce their property rights with shotguns; others use feral cats, cannons, balloons or plastic owls. If they don't, birds can eat them into poverty.
This is the time of year when sparrows, starlings, pigeons and other overwintering fowl start making a pest of themselves in barns and feedlots. Feed lines in dairy barns are black with birds and the backs of the cows are often slick with their excrement.
Farmers are usually averse to talking out loud about bird control, particularly when the ASPCA might be within earshot, but in the anonymity of online Internet communication it's been a hot topic. Here's what some of the farmers, extension agents and agricultural researchers who use the DAIRY-L mailing list had to report.
"We have used balloons with predator eyes," said a Utah dairy manager. "They looked pretty ridiculous. It sort of worked, and then within a couple days the birds totally ignored them."
An adult starling, according to some reports, will eat one-and-a-half times its body weight in feed per day if given the chance. Wintering flocks numbering 2,000 birds will consume a ton of feed a month or more.
The dairy then purchased a propane cannon which fires intermittently with a shotgun-like blast and scares off the birds. It doesn't seem to bother the cows, the manager said.
"Those cannons may not bother your cows, but they sure as hang bother me!" responded a Pennsylvanian. "I have nearly jumped over my truck, not knowing a propane cannon was nearby!"
"Bird-eye" balls work seem to work better if they're moved around from place to place, according to a Minnesota extension educator.
"Another couple tricks that seem to offer some help are strips of foil or aluminum pie tins hung in doorways or open windows as deterrents," he reported. "I know a few people who swear by plastic owls places around the building on rafters. I suspect they, too, would be more effective if moved from time to time."
A farmer in Maine suffering an infestation of starlings was saved by sparrow hawks. They moved into his barn and cleaned out his problem.
In New Hampshire, it was a large owl that frightened smaller birds away. Both farms are now looking for ways to attract birds of prey on a permanent basis.
A researcher in New York has been testing an electronic device that emits a distress call to frighten off birds. "The darn thing seems to scare birds away as long as the call matches the problem species. Of course, the birds just fly to the neighbors," he said.
Another dairy solved its bird problem by using mesh on all openings except the feed alley, and there they used clear plastic freezer curtains. It kept the birds out, but also the fresh air.
Folks in Indiana took more drastic measures. On a calm day they closed off their 30-by-50-foot barn after the cows were gone but before the birds left in the morning. Then they released 40 pounds of anhydrous ammonia into the air from a nurse tank.
"Within a few minutes the birds were dead, as well as a few mice," they reported. "Technical data: there are 300 starlings to the bushel."
by Michael Hofferber. Copyright © 1998. All rights reserved.
