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Songbirds
Fly Under Night-time Skies--Do Monarchs?
by Elizabeth Howard
May
6, 2004
Last night, a major influx of songbirds occurred where I live. When I
woke up this morning, there they were! High in a tree outside my window
in Vermont — fresh from Central America — a brilliant orange
oriole suddenly sang his song. From the meadow below came the exuberant
bubbling of bobolinks — a far cry from the South American grassland
where they spent the winter.
Many bird
species migrate at night, orioles and bobolinks
among them. Why do they travel in the dark? Let’s think this through
. . .
Adaptation |
An
"adaptation" is a physical or behavioral feature that
evolved in response to an organism's environment due to pressures
for survival. |
Remember,
migration is a behavioral adaptation. Let’s look at the songbird’s
environment. How does the behavior of migrating at night help songbirds
to survive?
- Stars:
The stars help songbirds navigate.
- Wind:
The winds die down at night, so flight is smoother.
- Predators:
The oriole’s predator, the hawk, can't fly at night so traveling
through unfamiliar territory is safer at night.
- Food:
Songbirds can fuel up during the day, when they can see, to prepare
for night-time flights.
- Temperature:
It's cooler at night, so exercising birds don't overheat as easily.
Journaling
Question Do
Monarchs Migrate by Night or by Day?
What about monarch butterflies? Do they travel at night too? Think about
the monarch’s environment. Think about what you’ve learned about
monarch migration. Consider your own experiences with butterflies. Then
answer this question:
- Do you
think monarch butterflies migrate during the night, the day, or both
night and day? Why?
- After
thinking this through, see monarch butterfly expert Dr.
Bill Calvert's response.
National
Science Education Standards
- An organism's
behavior evolves through adaptation to its environment.
- Biological
adaptations include changes in structures, behaviors, or physiology
that enhance survival and reproductive success in a particular environment.
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2004-2007 Journey North. All Rights Reserved.
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