A Costa's hummingbird hides and feeds out of line of sight to the very aggressive, Allen's hummingbird. The Allen's hummingbird will chase off the Costa's once noticed. Here's the first of several hummingbird images I'll post as I work through my "Hummingbirds of the Americas" project. A little about the birds... The Costa's Hummingbird is a resident of Northwest Mexico, Baja California, Southern California, western Arizona and southern Nevada. The male Costa's Hummingbird's courtship display is a spirited series of swoops and arcing dives, carefully utilizing a proper angle to the sun to show off his violet plumage to impress prospective mates. Each high-speed dive will be accented by a high-pitched sound (caused by the air flow over the tail feathers) as the male passes within inches of the female, who is perched on a nearby branch. Researchers have found that the Costa's Hummingbird can enter a torpid state, with slowed heart rates and reduced body temperatures, under low ambient nighttime temperatures. The hearts of torpid Costa's Hummingbirds beat about 50 times per minute, while those of non-torpid resting Costa's Hummingbirds beat 500 to 900 times per minute. The Allen's Hummingbird is found on the coastal strip of the Pacific ocean from Southern Oregon to Mexico. Breeds in moist coastal areas, scrub, chaparral, and forests. Winters in forest edge and scrub clearings with flowers. Allen's Hummingbirds closely resemble the smaller Rufus Hummingbirds and 10% of each species has the exact field markings of its counterpart, but for the most part, Rufus Hummingbirds have coppery backs and Allen's have greenish backs. Both the birds are distinctive by their metallic sounding wingbeat. And yes,... both birds show up our feeders (outside Los Angeles). Rendered in Poser 2012 without postwork. Model Credits: Flame Bush (Xfrog), Forget Me Nots (LB botanical) and Hummingbirds (Me)