(Wines&Vines) - Almost every grower loves to see hawks soaring over vineyards and owls roosting in owl boxes because that means the predatory birds are hunting for pests. But recent studies have shown that songbirds may be important grower partners, too. Songbirds such as western bluebirds, tree swallows, and violet-green swallows are voracious consumers of insects, especially while feeding their young. And unlike European starlings, a common pest, they don’t eat grapes and seeds, just bugs. “They rely solely on insects,” said Julie A. Jedlicka of the University of California, Berkeley, who has studied the impact of the cheery birds.