Seven subspecies of American robin are recognized. This species is shyer than the American robin. They are similar in size to the American robin. It is a large sized thrasher that is close in size to the American robin. For comparison, the blue whistling thrush commonly weighs twice as much as an American robin. In general appearance and habits it resembles other "Turdus" thrushes such as the American robin. The American robin has a place in Native American mythology. They are a valuable energy food for birds, especially the American robin. These include Stellars' Jays, Black-capped Chickadees, and the American Robin. Common birds are Red-tailed hawk, Steller's jay, American robin, American kestral, and Peregrine falcon. The American robin begins to breed shortly after returning to its summer range. The American robin is a known reservoir (carrier) for West Nile virus. The American robin is the state bird of Connecticut, Michigan, and Wisconsin. The American robin and house sparrow led bird species in the incidence of albinism. Cook (1939) described an hereditary albinism in the American robin ("Turdus migratorius" L., "Turdidae").