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Hummingbirds
(family Trochilidae) are small birds capable of hovering
in mid-air due to the rapid flapping of their wings (15
to 80 beats per second, depending on the size of the bird).
They are named for the characteristic hum of this rapid
wing motion. They are the only birds that can fly backwards.
Hummingbirds are attracted to many flowering plants—shrimp
plants, fuchsias, many penstemons, etc.—especially
those with red flowers. Hummingbirds feed on the nectar
of these plants. They are important pollinators, especially
of deep-throated flowers. Most species also eat insects.
Male hummingbirds are usually brightly coloured, females
duller. The males take no part in nesting. The nest is
usually a neat cup in a tree. Two white eggs are laid,
which are quite small, but large relative to the bird's
size. Incubation is typically 14-19 days. The Bee Hummingbird
(Mellisuga helenae) is, at 1.8 grams, the smallest bird
in the world. |
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A
typical North American hummingbird, the Ruby-throated
Hummingbird (Archilochus colubris) weighs approximately
3 grams and has a length of 7.6 cm (3 in). Hummingbirds
have the highest metabolism of all animals, a necessity
in order to support the rapid beating of their wings.
Their heartbeat can reach 500 beats per minute. They also
typically consume more than their own weight in food each
day, and to do that, they have to visit hundreds of flowers
every day. But at any given moment, they're hours away
from starving. Fortunately, they 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 heartrate and
rate of breathing are both slowed dramatically, reducing
their need for food. |
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