By MATEUSZ PERKOWSKI
Cannons, kites and other mechanisms eventually lose their ability to scare birds away from eating berry crops, but natural predators don't, said falconer Kort Clayton.
"Pest birds never get used to the idea of being chased by a falcon," said Clayton, Northwest operations manager at Airstrike Bird Control.
The company primarily operates in Oregon, Washington and California, chasing birds away from grower fields as well as solid waste plants, he said. Hiring a falconer generally costs $20,000 per season.
The method is primarily fear-based, as the falcons typically just scare the birds rather than eating them, Clayton said. It's undesirable for them to actually catch their prey, since that can distract the falcon and prevent it from responding to commands.
Falconry is an expensive method for bird abatement, but it's a consistently reliable way to avoid major crop losses for farmers who are prone to such damage, said Charlie Anderson, an agronomist at Skagit Farmers Supply.
"They habituate to everything so quickly," he said of pest birds.
Anderson said he once participated in a field trial in which birds consumed 28 percent of a blueberry crop despite various visual and audible devices meant to dissuade them.
Pyrotechnics were once commonly used by farmers to scare off birds, but stricter federal regulations have made the practice less convenient, he said. The explosions are also not effective over the long term.
"They're good for a couple days before the birds realize that nobody is hurting them," Anderson said.
With falcons, crop losses aren't completely avoided but the damage is minimal, he said. "It's not 100 percent but you're down in the single digits definitely."
Birds like starlings need to eat their own weight in food each day, so if the process becomes too complicated they'll simply move elsewhere, said Anderson. An added bonus is that they often remember the falcon after several years and begin to avoid the location.
"I think it's something visceral," he said.
For the cost of hiring a falconer to pencil out, the farmer must usually manage a large property, said Clayton. One falconer is effective for up to 900 acres.
In some cases, growers on adjacent parcels pool together to make the practice more cost-effective, he said. Falconers usually travel fields on all-terrain vehicles and operate from sunrise to sunset, to prevent pest birds from adapting to their behavior.
The falcons themselves can live about 20 years or longer, though they're working life is usually about five years because they can get lost or fly away, said Clayton.
Last spring, Clayton lost a falcon when it traveled about 100 miles in two days, he said. Though the birds are outfitted with tracking devices, finding them can be too difficult in remote terrain.
Falcons are taught to perform their job with food associations -- first they're trained to tolerate the handler, then to return to him on command, and then to manage their flight, Clayton said.
They're never actually taught not to eat the pest birds, he said. Rather, the falcons are fed enough to sate their hunger, which doesn't discourage them from giving chase.
"If they're well fed, they don't try very hard to catch things," he said.