the rufous hummingbird (selasphorus rufus) is a small hummingbird , about 8 cm (3.1 in) long with a long , straight and slender bill .
these birds are known for their extraordinary flight skills , flying 2,000 mi (3,200 km) during their migratory transits .
it is one of seven species in the genus selasphorus .
the adult male has a white breast , rufous face , flanks and tail and an iridescent orange-red throat patch or gorget .
some males have some green on back and/or crown .
the female has green , white , some iridescent orange feathers in the center of the throat , and a dark tail with white tips and rufous base .
the female is slightly larger than the male .
females and the rare green-backed males are extremely difficult to differentiate from allen's hummingbird .
this is a typical-sized hummingbird , being a very small bird .
it weighs 25 g (0.0710.176 oz), measures 79 cm (2.83.5 in) long and spans 11 cm (4.3 in) across the wings .
they feed on nectar from flowers using a long extendable 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 homea 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 -20c .
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 birds wing movements on film , which enabled the discovery that the hummingbirds hovering is achieved due primarily to its wings downstroke (which accounts for 75% of its lift) rather than its upstroke (which makes up the additional 25% of the lift) .
the rufous-tailed hummingbird (amazilia tzacatl) is a medium-sized hummingbird that breeds from east-central mexico , through central america and colombia , east to western venezuela and south through western ecuador to near the border with peru .
the larger escudo hummingbird from isla escudo de veraguas in panama is commonly considered a subspecies of the rufous-tailed hummingbird .
this is a common to abundant bird of open country , river banks , woodland , scrub , forest edge , coffee plantations and gardens up to 1850 m (6000 ft) .
the adult rufous-tailed hummingbird is 1012 cm (44.8 in) long and weighs approx .
5.2 g (0.2 oz) .
the throat is green (edged whitish in the female), the crown , back and flanks are green tinged golden , the belly is pale greyish , the vent and rump are rufous and the slightly forked tail is rufous with a dusky tip .
the almost straight bill is red with a black tip; the black is more extensive on the upper mandible , which may appear all black .
immatures are virtually identical to the female .
the call is a low chut , and the males song is a whistled tse we ts we or tse tse wip tseek tse .
the female rufous-tailed hummingbird is entirely responsible for nest building and incubation .
she lays two white eggs in a compact cup nest constructed from plant-fibre and dead leaves and decorated with lichens and mosses 16 m high on a thin horizontal twig .
incubation takes 1519 days , and fledging another 2026.  the food of this species is nectar , taken from a variety of flowers , including  heliconias and bananas .
like other hummingbirds , it also takes small insects as an essential source of protein .
rufous-tailed hummingbirds are very aggressive , and defend flowers and shrubs in their feeding territories .
they are dominant over most other hummingbirds .
