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Where
do hummingbirds live?
All
hummingbirds are found in the Western Hemisphere. Hummingbirds occur in
many different habitats, from the wettest to the driest, and from sea
level to over 14,000 feet (4400 meters) in the Andes mountains.
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What
do they eat?
Most
people know that hummingbirds drink flower nectar. But studies have shown
that hummingbirds also are masters of catching the tiniest insects, and
that at least 50% of their diet is actually insects. Many insects are
active even at extremely low temperatures. Many gardens also now have
plants that bloom during fall and winter months, providing a source of
nectar AND insects.
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How
do they survive the winter?
One
way hummers survive extreme conditions is called torpor. Torpor is a kind
of deep sleep, whereby an individual hummingbird lowers its metabolism
by 95%, and thus body temperature (normally around 104°F/40°C),
to just above the point of death by hypothermia!
Hummingbirds
are among the smallest of all warm-blooded animals and lack the insulating
downy feathers typical of many other bird species. Due to this and their
small body size, hummingbirds rapidly lose body heat to their surroundings.
Even sleeping hummingbirds have large energy demands that they must meet
simply to survive. Going into nightly torpor conserves a lot of energy,
allowing the bird to survive very cold and hot nights. Awakening from
torpor takes 20 minutes or more, and happens automatically about an hour
before dawn.
Folks have
reported finding “dead” hummers hanging upside down, in the morning; but
these usually turn out to be individuals in deep sleep (torpid), that
have somehow loosened their foot grip just enough to slip on the perch,
but not fall. They eventually wake up and begin the daily routines. Other
species known to go into torpor include swifts and swallows.
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How
many different kinds of hummingbirds exist?
There are more than 330 recognized species. Scientists are still occasionally
finding new species in tropical regions.
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Can
they really hover?
Yes! Due to a unique muscle/bone arrangement, hummingbird wings move
in a super-efficient figure-eight pattern. This allows them to fly in
any direction and hover for prolonged periods. Hover flight requires up
to 60 wing beats/second.
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How
are hummingbirds captured for research?
Researchers
use various kinds of traps, built like a bird cage, and usually operated
by a pull-string. A feeder is hung in this cage, and when the hummingbird
flies in, the string is pulled which closes the door behind the bird.
A very fine mesh net, called a “mist net”, is also sometimes used. The
birds do not see these, and so fly into them and become entangled in the
soft folds of these nets.
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How
big is a hummingbird band?
What does it look like?
Birds are
fitted with a light-weight aluminum band imprinted with a unique number.
Each band is 5.6 mm in length, and weighs about 0.005 grams. Thus, it
takes 200 bands to weigh a gram, or, 5,500 to weigh an ounce. These bands
are sent to banders in flat sheets. The bander must cut, file and polish
smooth each band before placing it on a bird.
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Does
banding harm the bird?
No.
The bander places a partially opened hummingbird band into special banding
pliers and slides it over the leg of the bird. The band is then crimped
shut and checked to assure that it fits well. A properly fitted band does
not harm the bird. There are records of banded individuals returning to
feeders for 5 years or more.
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Cool
Hummingbird Links:
www.hummingbirds.net
- General site with lots of good info on natural history, feeding; also
hosts migration mapping page (part of Journey North).
http://trochilids.tripod.com
- Hummingbird Mapping Projects; lots of links to other hummer stuff.
www.hummingbirdsplus.org
- The Hummer/Bird Study Group; biggest promoters of hummer banding; this
group "wrote the book" on ruby-throats.
www.rubythroat.org
- Operation Rubythroat; lots of educational material, especially for grades
K-12.
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