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| Ruby-throated Hummingbird (image by Rut Forsgren) |
By Ruth Forsgren
Hummingbirds are fascinating little critters. It is amazing
how something so small can capture the hearts and imaginations of so many
people, birds and non-birders alike. There are about 350 species of
hummingbirds in the world and all of them are found only in the Americas. There
are eight species that are considered regularly occurring in the United States
and only one that nests east of the Mississippi River, the Ruby-throated
Hummingbird.
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| Female Ruby-throated Hummingbird (image by Ruth Forsgren) |
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| Both males and females have a green back and head. (image by Ruth Forsgren) |
Ruby-throated Hummingbirds are small. They average between
2.5 to 3.5 inches long, they tip the scales at a whopping two to six grams
(remember that a U.S. pennies weigh 2.5 grams) and their wingspan ranges from
three to four inches. Both males and females have a brilliantly emerald green back and head. They would definitely be welcome in the Emerald City of Oz. Adult males have the bright, shiny fire
engine red gorget, or colored feathers on the throat. The feathers of the
gorget are iridescent. That means that there isn’t pigment causing the color,
instead it is caused by the refraction of light off of microscopic structures
in the bird’s feathers. When thinking of refraction, think of a prism that
splits light into strong component colors. If light is not present or is at the
wrong angle the gorget will appear dark. The male can control the feathers to
an extent, helping to showcase the brilliant color.
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| Male Ruby-throated Hummingbird with dark gorget. (image by Ruth Forsgren) |
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| Male Ruby-throated Hummingbird with gorget refracting light. (image by Ruth Forsgren) |
Ruby-throated Hummingbirds nest throughout the eastern half
of North America. The habitats that they
can utilize include open woodlands, forest edge, parks, gardens and backyards.
They usually build their nests on top of a branch anywhere from ten to forty
feet above the ground. The nest is built of thistle or dandelion down held
together with spider silk and then camouflaged with lichens or moss and take
from six to ten days to complete.
The mating dance is fun to watch. The male will do what is
referred to as a U dance. He will go straight up usually about six to ten feet
(but can go as far as 50 feet up) fly straight back down, over and back up in a
U shape. If you look carefully the female is typically in the bottom of the U.
Once she has shown interest, if she perches he will fly very quickly from side
to side directly in front of her in a face to face dance.
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| Flying backwards off the feeder. (image by Ruth Forsgren) |
Hummingbirds are incredibly controlled fliers; they can move
their wings differently than other birds. This ability allows them to fly in
any direction, forward, backwards, sideways and even upside-down. But one thing
they cannot do is walk or hop because their legs are too short. Hummingbirds
and swifts were placed in the same taxonomic order; Apodiformes, which means
without feet. The only way a hummingbird can scratch or groom its head is by
raising the foot up from under the wing.
These tiny flying machines really use up the energy. Their
wings move at over 50 beats per second and their heartrate is about 1200 beats
per minute or 20 beats per second! They cannot feed at night to refuel their
bodies so most hummingbirds spend a lot of their nights in a state known as
torpor. Torpor is a form of hibernation. Torpid animals can slow their body
processes or metabolism, according to surrounding air temperatures. This allows
them to drop their energy consumption down to 5 to 30% of what they normally
use when awake and just resting.
The Ruby-throated Hummingbirds usually return to the
Chippewa Valley during the first week of May. The advance guard members are
seen first but the main thrust of returners seem to show up when the
crabapples, wild plum and serviceberry start to bloom.
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| Hummingbirds at a sugar water feeder. (image by Ruth Forsgren) |
Hummingbirds will readily come to nectar feeders. The recipe
is simple four-parts water to one-part white cane sugar. Boil the water first,
then add the sugar, and stir until dissolved. You can use hot tap water but
your mixture will last a little longer if boiled, and for me it is easier to
get the sugar to dissolve. DO NOT add red dyes! It is not needed to attract the
birds and may actually be harmful to them. Remember that this is a syrup and
will get sour in hot weather, so change the mixture every couple days. In the
fall leave hummingbird feeders up for about two weeks after your last sighting.
Your feeder will not make them stay too long but it might provide the energy
needed if there has been an early killing freeze.
So when out in the flower garden keep an eye and ear open
for these tiny little flying jewels.
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| Female hummingbird feeding on Salvia (image by Ruth Forsgren) |
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| Female Ruby-throated Hummingbirds have a white throat and white spots on the outer tail feathers. (image by Ruth Forsgren) |
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| Male Ruby-throated Hummingbird (image by Ruth Forsgren) |
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