How Hummingbirds Get the Word Out!
a Mate is Important!
species of animal can only survive if it can reproduce. In order for this
to happen, males and females must get together to mate, and must have
enough resources to feed their babies. Many mammals attract mates and
discourage competitors by marking their territories with an odor. Birds,
like humans, are more sensitive to sights and sounds than scents. Male
songbirds use both their song and bright parts of their plumage to attract
a mate and to declare the boundaries of their territory. When male
Songbird A hears male Songbird B singing from A's territory, A chases
B off. The same thing happens if A sees B's bright colors on his territory.
If B is on his own territory, hearing B's song or seeing his bright plumage
makes A pull back a little. By spacing themselves this way, songbirds
can minimize fighting while spacing themselves so everyone can find enough
food for their young.
Hummingbirds twitter, but their voices do not carry far
enough to be useful in declaring a territory. And even though their colors
are so beautiful and brilliant, they are iridescent, only glittering
from some angles and appearing flat and black or gray from other angles.
Also, hummers are so tiny that the colors don't show up at a distance.
Fortunately, their special flying abilities give them a wonderful alternative
for advertising their territory and attracting a mate: skydancing.
Hummingbirds have unique wing bones and muscles, allowing them to fly
straight up, straight down, backwards, and forwards. And their wings flap
so very fast (up to 200 beats per second in a display!) that they make
a buzzing sound. A territorial hummingbird flies in a pattern--usually
a U or an oval--which it repeats over and over, wings buzzing to make
the display even more noticeable.
the flight patterns of a Ruby-throated Hummingbird . It makes its loudest
wing sounds when near the bottom of the display, and repeats the pattern
over and over. To HEAR the sounds of a ruby-throat while displaying, click
(Recording by Lang Elliott)
display catches the attention of other hummingbirds, and people may notice
too! Journey North Science Writer Laura Erickson was hiking in Yellowstone
National Park when she came upon a Calliope Hummingbird doing its display
above a noisy river. Even over the gurgling water, Laura could hear the
hummingbird's wing sounds when she was at least 100 meters away. From that
distance she caught sight of it diving and coming up in a deep U pattern,
over and over. Many times she's seen Ruby-throated Hummingbird males dance
in their more shallow U-pattern (usually this display is only 10-40 feet
deep), and once Laura saw a Rufous Hummingbird making what looked to her
eye as ovals in the sky, like a pilot making loop-the-loops over and over.
For the hummer, this display is important communication, but it sure looked
like fun! Wheeeeeeeee!
This! Paddle Ball Display Patterns
All you need is a "paddle-ball" set and a long tape measure.
starts playing paddle ball at the far end of the playground or a long
sidewalk, simply bouncing the ball up over and over in the same place.
Other students at the other end of the playground or sidewalk, slowly
walk toward the "bouncer." At the point where each student first
sees the bouncing ball in the air, s/he should mark the sidewalk with
chalk. Then students measure the distance from their own mark to where
the "bouncer" is standing. The average of these distances is
the radius of the bouncer's territory.
The rubber ball in most paddle ball sets is close to the
size of a hummingbird. If a hummingbird's aerial display were comparable
to the paddle ball's, what would the AREA of the hummer's territory be?
Of course, other hummingbirds can observe an aerial display while perched
high in trees or flying, which makes the effective area of the display
Deeper: An Intriguing Question
bird books, even scientific ones, describe the display pattern of Rufous
Hummingbirds as an oval. But it's hard to find people that have ever seen
them do this. For example, Mike Patterson has been watching Rufous Hummingbirds
for 20 years without ever seeing them fly in an oval display. Do they really
do this? Find the answer, and more questions, here: