
Hummingbird
Facts and Feats
Pollination
Uniquely adapted for feeding from flowers, hummingbirds are more
efficient at dispersing pollen than many insects are. Pollen dusted
on the bird's bill, throat, or forehead is easily transferred from
flower to flower. Hummingbirds are also more reliable pollinators;
insects become inactive on cold or rainy days, but hummingbirds
visit flowers regardless of the weather. Flowers adapted to pollination
by hummingbirds are often red because this color is not visible
to most insects. They also lack a fragrance, because hummingbirds
have little or no sense of smell. A tubular-shape and the absence
of a landing platform are among other adaptations designed to help
reserve the flower's nectar for hummingbirds and to discourage
insects.
Flight
Hummingbirds are so adept at flying that they have no need to walk.
Their small feet serve mostly as retractable landing gear used
for perching. They are the only birds that can hover and fly backward,
forward, sideways, straight up or down, and even upside down. Their
wings can beat 70 to 80 times per second, giving them an average
flight speed of 25 to 30 miles (40 to 48 kilometers) per hour.
Hummingbirds must often eat more than twice their weight in nectar
and insects every day as fuel for flight. A human with a weight-specific
metabolic rate equal to that of a hummingbird would need to take
in an estimated 155,000 calories a day!
Migration
To escape intense competition in the tropics, several hummingbird
species migrate to the United States and Canada to breed each spring.
It is amazing they make it here at all! Ruby-throated hummingbirds
travel all the way from Central America to breeding grounds throughout
the entire eastern United States and most of southern Canada. For
most, the migration includes a remarkable nonstop flight across
the Gulf of Mexico (500 to 600 miles or 800 to 1,000 kilometers).
Weighing only about six grams when they set out (about twice their
normal weight), and with a brain the size of a BB pellet, they
are somehow able to complete this journey and return year after
year to the same territories. Females have even been known to return
to the same nest several years in a row. Rufous hummingbirds, which
breed as far north as southern Alaska, have the longest migration
route of any hummingbird, traveling up to 3,000 miles (4,800 kilometers)
from Central America.