Selasphorus rufus (U.S. Fish and Wildlife Service )
Selasphorus rufus (Gmelin, 1788)
* Syst.Nat. 1 pt1 p.497
The Rufous Hummingbird (Selasphorus rufus) is a small hummingbird, about 8 cm long (3 inches) with a long, straight and very slender bill. The female is slightly larger than the male.
The adult male, (shown in the photo), has a white breast, rufous face, upperparts, flanks and tail and an iridescent orange-red throat patch (gorget). Some males have some green on back and/or crown. The female has green upperparts with some white, some iridescent orange feathers in the center of the throat, and a dark tail with white tips and rufous base. Females and the rare green-backed males are extremely difficult to differentiate from Allen's Hummingbird.
They feed on nectar from flowers using a long extendible tongue or catch insects on the wing. These birds require frequent feeding while active during the day and become torpid at night to conserve energy.
Because of their small size, they are vulnerable to insect-eating birds and animals.
Their breeding habitat is open areas and forest edges in western North America from southern Alaska to California. This bird nests further north than any other hummingbird. The female builds a nest in a protected location in a shrub or conifer. The male aggressively defends feeding locations within his territory. The same male may mate with several females.
They are migratory, many of them migrating through the Rocky Mountains and nearby lowlands in July and August to take advantage of the wildflower season there. They may stay in one spot for considerable time, in which case the migrants, like breeding birds, often aggressively take over and defend feeding locations. Most winter in wooded areas in the Mexico state of Guerrero, traveling over 2,000 miles by an overland route from its nearest summer home—a prodigious journey for a bird weighing only three or four grams.
This is the western hummingbird most likely to stray into eastern North America. There has been an increasing trend for them to migrate east to winter in the eastern United States-(Florida), rather than in Mexico. (They do arrive at the Turks and Caicos Islands.) This trend is the result of increased survival with the provision of artificial feeders in gardens. In the past, individuals that migrated east in error would usually die, but now they often survive. Provided sufficient food and shelter is available, they are surprisingly hardy, able to tolerate temperatures down to at least -20°C.
Research on hummingbird hovering
In 2005, a research team led by Dr. Douglas Warrick of Oregon State University used trained rufous hummingbirds in a study to determine the mechanics of hummingbird hovering. The study employed digital particle imaging velocimitry to capture the bird’s wing movements on film, which enabled the discovery that the hummingbird’s hovering is achieved due primarily to its wing’s downstroke (which accounts for 75% of its lift) rather than its upstroke (which makes up the additional 25% of the lift).
1. ^ "Master fliers of the bird kingdom". BBC. 2005-06-27. http://news.bbc.co.uk/2/hi/science/nature/4124666.stm. Retrieved 2009-10-30.
* BirdLife International (2004). Selasphorus rufus. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 9 May 2006. Database entry includes justification for why this species is of least concern
Source: Wikipedia, Wikispecies: All text is available under the terms of the GNU Free Documentation License