My favorite bird

      The Ruby-throated Hummingbird (Archilochus colubris), is a small hummingbird. It is the only species of hummingbird that regularly nests east of the Mississippi River in North America.   The Ruby-Throated Hummingbird is 7-9 cm long with an 8-11 cm wingspan, and weighs 2-6 g. Adults are metallic green above and greyish white below, with near-black wings. Their bill is long, straight and very slender.   The adult male, shown in the photo, has an iridescent ruby red throat patch which may appear black in some lighting, and a dark forked tail. The female has a dark rounded tail with white tips and generally no throat patch, though she may sometimes have a light or whitish throat patch.   The male is smaller than the female, and has a slightly shorter beak. A molt of feathers occurs once per annum, and begins during the autumn migration.   The breeding habitat is throughout most of eastern North America and the Canadian prairies, in deciduous and pine forests and forest edges, orchards, and gardens. The female builds a nest in a protected location in a shrub or a tree.   The Ruby-throated Hummingbird is migratory, spending most of the winter in southern Mexico, Central America as far south as South America, and the West Indies. It breeds throughout the eastern United States, east of the 100th meridian, and in southern Canada in eastern and mixed deciduous forest.   Ruby-throated hummingbirds are solitary. Adults of this species typically only come into contact for the purpose of mating, and both males and females of any age aggressively defend feeding locations within their territory. The aggressiveness becomes most pronounced in late summer to early fall as they fatten up for migration.    They feed frequently while active during the day and when temperatures drop, particularly on cold nights, they may conserve energy by entering hypothermic torpor.   Due to their small size, they are vulnerable to insect-eating birds and animals.