Scientists identify previously unknown `hybrid zone` between hummingbird species
(PHYSorg.com Biology)

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.