Owls:
Whooooo's Finding Romance in the Cold of
Winter?
North American
humans celebrate our most romantic holiday, Valentine's Day, in the dead
of winter. Few North American birds are thinking about the birds and the
bees--they're too caught up in surviving the winter. But one group of
birds finds February the most romantic month of all--owls.
The Great Horned Owl Keeps a Warm Nest
Great
Horned Owl
Photo courtesy of Marshall Iliff.
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The most
widespread, common owl on the continent is the Great Horned Owl. This
hardy species can not only survive temperatures close to forty below zero--it
can sit in that frigid air while incubating eggs, keeping them a toasty
37 degrees C! A healthy bird's body temperature fluctuates more than ours
does, but a Great Horned Owl's body temperature in Minnesota in during
February has been recorded from 37.5 to 40.4 degrees C. The owl's abundant,
thick body feathers allow her to share her warmth with the eggs while
keeping the frigid outside air out. Of course, her body is warming the
eggs from above. But their nest is in an unheated tree. What protects
the eggs from icy temperatures below?
Owls Call
to Find Mates
For owls to lay eggs in February and March, they must first find a mate.
Normally owls are solitary birds, and the way they attract a mate from
a distance is by hooting. Both males and females call to one another.
Great Horned Owls have a variety of calls, so complex that ornithologists
don't really understand the meanings of most of them. But they have determined
that most male calls are deeper, richer, and longer than female calls.
- Listen
to the hoot
of two Great Horned Owls. (Wait for download,
404K file.)
- This is
the snapping call
Great Horned Owls might make when they land right near eachother.
If you listen carefully, you might hear it snapping its bill. (Wait
for download, 246K file.)
- This is
the warning call
Great Horned Owl parents make when a potential predator approaches their
nest or fledglings. What might have caused them to make this particular
call? (Answer: Lang Elliot with his tape recorder!) (Wait
for download, 297K file) All
recordings courtesy of Lang
Elliot.
Practice
Your Hoot
A lot of Great Horned Owl calls are easy for humans to imitate. Can you
hoot like a Great Horned Owl? With practice, you might be able to call
a Great Horned Owl in so you can see it! This works best at nighttime.
Before you go, read about a father and daughter calling for owls in
Owl Moon by Jane Yolen. It's available in any library.
(See our Owl Moon Reading and
Writing Connection!)
In daytime,
you are not likely to hear owls, and it's hard to see them camouflaged
against tree trunks, hiding in the shadows. But one bird searches out
owls and when it finds them, it's mobbing caws can be heard for a long
distance.If
you hear ANGRY-sounding crows, check it out! There may be an owl closer
than you think!
Journaling
Questions
- It's interesting
that owls can successfully hatch eggs in such a cold season, but the
big question is, WHY any bird would even think about laying eggs in
February. What
are some reasons why North American owls might breed in mid and late
winter?
- How
do you think owl eggs keep their heat while in an unheated nest?
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2004 Journey North. All Rights Reserved.
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