Scientists identify previously unknown 'hybrid zone' between hummingbird species

We usually think of a species as being reproductively isolated—that is, not mating with other species in the wild. Occasionally, however, closely related species do interbreed. New research just published in The Auk: Ornithological Advances documents the existence of a previously undiscovered hybrid zone along the coast of northern California and southern Oregon, where two closely related bird hummingbirds, Allen's Hummingbird and Rufous Hummingbird, are blurring species boundaries. Researchers hope that studying cases such as this one could improve their understanding of how biodiversity is created and maintained.