Vineyard and orchard owners are also using barn owls to keep rodent populations in check. Farmers provide nests for owls on the perimeter of their property. During the night and early morning hours, owls swoop down to feed on burrowing squirrels and gophers. Napa Valley grape growers have used predatory birds to control flocks of grape-eating starlings, finches and robins that move into vineyards when the fruit ripens. As grapes reach 15 percent sugar, the birds start to cause damage, but because wineries may not pick the grapes until more sugar develops, farmers need an effective way to control crop damage.
Many growers use kestrels, also known as sparrow hawks, to keep unwanted birds away.
Boxes built for kestrels, Western Bluebirds and red-tailed hawks help keep these vineyard sentinels on the job. Many farmers use cover crops and native plants to provide habitat for beneficial insects at the edge of fields, between rows of fruit and nut trees and in vineyards. One California nursery, Cornflower Farms of Elk Grove, specializes in plants that are hosts to beneficial insects. They propagate elderberry trees, quail bush and other plant varieties for agricultural clients. All rights reserved.