Factoids from wiki:
~They can hover in mid-air by rapidly flapping their wings 15–80 times per second (depending on the species). They can fly backwards, and are the only group of birds able to do so.
~Hummingbirds do not spend all day flying, as the energy costs of this would be prohibitive; the majority of their activity consists simply of sitting or perching. Hummingbirds feed in many small meals, consuming many small invertebrates and up to five times their own body weight in nectar each day. They spend an average of 10-15% of their time feeding and 75-80% sitting and digesting.
~With the exception of insects, hummingbirds while in flight have the highest metabolism of all animals, a necessity in order to support the rapid beating of their wings. Their heart rate can reach as high as 1,260 beats per minute, a rate once measured in a Blue-throated Hummingbird. They also typically consume more than their own weight in nectar each day, and to do so they must visit hundreds of flowers daily. At any given moment, they are only hours away from starving.
~Hummingbirds are capable of slowing down their metabolism at night, or any other time food is not readily available. They enter a hibernation-like state known as torpor. During torpor, the heart rate and rate of breathing are both slowed dramatically (the heart rate to roughly 50–180 beats per minute), reducing the need for food. Most organisms with very rapid metabolisms have short life-spans; hummingbirds, however have been known to survive in captivity for as long as 17 years.
~Hummingbirds are found only in the Americas, from southern Alaska to Tierra del Fuego, including the Caribbean. The majority of species occur in tropical Central and South America, but several species also breed in temperate areas. Only the migratory Ruby-throated Hummingbird breeds in continental North America east of the Mississippi River and Great Lakes. The Black-chinned Hummingbird, its close relative and another migrant, is the most widespread and common species in the western United States, while the Rufous Hummingbird is the most widespread species in western Canada.
~Most hummingbirds of the U.S. and Canada migrate south in fall to spend the northern winter in Mexico or Central America. A few southern South American species also move to the tropics in the southern winter. A few species are year-round residents in the warmer coastal and interior desert regions. Among these is Anna's Hummingbird, a common resident from southern California inland to southern Arizona and north to southwestern British Columbia.
~The Rufous Hummingbird is one of several species that breed in western North America and are wintering in increasing numbers in the southeastern United States, rather than in tropical Mexico. Thanks in part to artificial feeders and winter-blooming gardens, hummingbirds formerly considered doomed by faulty navigational instincts are surviving northern winters and even returning to the same gardens year after year. Individuals that survive winters in the north, however, may have altered internal navigation instincts that could be passed on to their offspring. The Rufous Hummingbird nests farther north than any other species and must tolerate temperatures below freezing on its breeding grounds. This cold hardiness enables it to survive temperatures well below freezing, provided that adequate shelter and feeders are available.
