Birds Habitat Generalists - Page 2

Perhaps the best-known generalist is the House Sparrow. Like most of us, its ancestors were immigrants; the House Sparrow was originally a European bird that was brought here to control garden insects. Many wagon trains in the last century took along a few caged House Sparrows to release at their destination. Although not prone to much wandering, this species has spread over most of North America.

As with most generalists, House Sparrows are nearly omnivorous and are not too particular about their best sites, although they are generally cavity nesters. Extremely prolific birds, House Sparrows nest in outdoor lighting fixtures, in birdhouses, and in the nooks and crannies of buildings, as well as in trees. They are adaptable in finding food as they are in finding nest sites. This adaptability makes them sturdy survivors. They have been known to feed at night under electric light to glean insects from car radiator grills, and to survive severe winters in Manitoba by taking advantage of the warmth of buildings, and of waste grain and other foods resulting from human activities.

It is hard to imagine a native North American species with as broad a niche as the house Sparrow, but the niche of the American Robin may exceed it in some ways. The House Sparrow, though more adaptable in terms of food and nest site, is never far from human habitation; the Robin is at home in urban areas and wilderness forest. Other notable North American generalists include the Northern Mockingbird, the Common Grackle, crows, and jays.