Kestrels scare off cherry-thieving birds
To attract kestrels to the orchard, put boxes well away from human activity.
Ben Dover sells kestrel boxes mainly to cherry growers, though they’re also catching on with grape, apple, and blueberry growers.
Some enterprising business people are harnessing the hunting prowess of falcons and kestrels to rid Washington State orchards of starlings that rob growers of as much as 10 percent of their crop. While their methods may differ, they get similar results: significantly higher cherry yields and more profits for growers.
Former grower Ben Dover was so impressed after installing a couple of kestrel nesting boxes in his Yakima cherry orchard, which he has since sold, that he went into business selling and installing them. He has sold more than 450 of the boxes since launching his Orchard Guard business two years ago.
Dover’s friend Lee Stream, who retired after 30 years as a biologist with the state Department of Fish and Wildlife, said kestrels are plentiful throughout the Yakima Valley.
The key to attracting kestrels, the smallest members of the hawk family, also known as sparrow hawks, is providing them a well-situated nesting box with a good view of their surroundings and, hence, their prey.
“It’s a little bit like that movie Field of Dreams, Stream said. “If you build it, they will come.
“If you have boxes put up where kestrels will come to them, it works pretty well.”
Although Dover sells mainly to cherry growers, his boxes are catching on with grape, apple, and blueberry farmers as well.
“I tell them I don’t claim to have experience with apples and grapes,” Dover said. “The only claim I make is that it worked on my cherries.”
Through trial and error, Dover has determined where to position the boxes.
“I walk the orchards with the farmers and decide on the best place to put them up,” he said.
Because people make the birds skittish, he advises growers to put boxes as far as possible from human activity. Once the birds are established, people don’t bother them as much.
The Audubon Society notes as well that starlings, which nest close to buildings, often appropriate boxes installed too close to humans, defeating the purpose.
“If kestrels really want to be there,” Dover said, “those other birds don’t have a chance. And once they’ve established a nest in the box, they’re likely to return and breed.”
Visiting the orchard he used to own, Dover points out a wind machine that was popular with pesky starlings. “I used to have to get up there every day and clean out the wind machine [of nesting starlings],” Dover said. “I installed a [kestrel] box across the road, and kind of forgot about it” in spring 2004.
It didn’t register that kestrels had moved in until he finally noticed there were far fewer birds around. Shortly thereafter, Dover and his wife sold the orchard and their on-site bed and breakfast, and Dover took up his present vocation.
“I’d never heard of anyone [using kestrel boxes] in the valley before now,” he said. “I’ve gotten around enough now so that people are hearing about it. I’m the first one to really develop it.”
Dover said he’s sold boxes to growers in Oregon and Montana, and as far away as Ontario, Canada, his sole international sale.
Their distinct silhouette and flight behavior make kestrels easy to spot.
“If you see a bird in the air and it’s hovering, that’s a kestrel,” Stream said. “He’s just hovering and waiting to spot prey and then dive on it. With their pointed wings, they can fly really fast.”
In fact, kestrels, which range from 9 to 12 inches in length and can live for more than ten years, can reach 60 miles per hour when they’re diving.
Stream said the only circumstance restricting the rural kestrel population is locating suitable nesting places, as they don’t build their own nests.
“They use artificial structures as well as holes in trees,” Stream said. “The boxes are providing a place for them to nest.”
Because of deforestation, and agricultural and residential development, he added, there aren’t a lot of old trees around with places for them to nest, and newly planted trees don’t have cavities like the old ones.
Kestrel boxes should be placed on freestanding poles or trees 10 to 30 feet above the ground, facing southeast in the center of the orchard. A guard around the post will prevent squirrels and predators from reaching the box. Place two to three inches of wood chips in the bottom. Boxes should be checked every week or so to remove starling eggs and nests.