My new
book, Too Hot? Too Cold? Keeping BodyTemperature Just Right (February 2013), grew out of many years researching animals
and learning how each one has adapted in its own way to the weather and
temperature of its habitat. Some animals migrate or hibernate; others grow
thick coats of fur in winter and shed it in summer; some, such as those that
live in the desert, restrict their activities to night, when the air is cooler. I began to realize that there were many
parallels between animals and the way people adjust to variations in temperature
in the places where they live. We may not grow thick fur to keep warm, but we
do put on heavy coats and jackets when it is cold outside.  | ||
| Caroline Arnold, age 10, with her brothers |
I grew up
in Minnesota
where winters are cold and summers are hot. When I was ten, my mother took a
photo in front of our house of me and my brothers all bundled up in our
snowsuits and mittens on a snowy February day. She wrote on the back of the photo that the temperature that day was
minus fourteen degrees Fahrenheit! I
have fond memories of sledding and ice skating on cold winter days in Minneapolis. In summer,
when temperatures soared into the nineties, my brothers and I stayed cool by swimming
in the lake not far from our house.
I
now live in Los Angeles, California, where the seasonal variations
are not so extreme. Even so, there are
clear differences between winter and summer. On warm summer days, I often see
lizards sunning themselves in my driveway. On cool winter days, the lizards
hide among the rocks. In spring and
fall, I enjoy watching birds as they migrate through southern California on their way to and from their
summer homes farther north.
As I
worked on the book, I tried to think of activities that would help readers
understand the concepts I was describing. It is one thing to read about an idea, and another to experience
it. Here are three simple activities you
can do that are related to information presented in Too Hot? Too Cold?
Getting
Heat From the Sun
Dark
colors are good for absorbing the sun’s heat. That’s why vultures will hold out their dark wings on cold mornings to
catch the sun’s rays. Light colors reflect the sun and help keep an animal
cool. The addax, an antelope that lives on the Arabian
Peninsula, has a light-colored summer coat to help protect it from
the desert sun.
Activity: Hot Rocks
In this
activity you can test how well dark and light colors absorb the sun’s heat.
You
will need:
Two rocks (about the size of your
fist), white
paint, black
paint, a paintbrush
Paint
one rock white and the other rock black. Put both rocks in the sun and wait for one hour. Then feel the rocks. Which rock feels
warmer?
The
white rock reflects the sun’s rays and stays cool. The black rock soaks up
the sun’s rays and becomes warm. To stay cool on a hot day, would you wear a dark shirt or
a light one?
Migrating
to Keep Warm or Cool
Some
animals leave their homes, or migrate, when the weather gets too cold or too
hot. Many birds migrate. Some of them fly thousands of miles between
their winter and summer homes. Strong
wings make them good flyers.
Activity: Wingspan Measuring Tape
Have you
ever wondered what kind of bird would you be, if you could fly? A bird flies with its arms, which are covered
with feathers. Stretch out your arms as if you were flying. Here's how you can
make a measuring tape to find out your wingspan...
You will
need: heavy paper (such as cardstock),
scissors, tape, a pencil, and a bird guidebook.
Cut the
paper in 1.5 inch strips. A paper cutter works well if you have one. Or, use
your scissors. You will have eleven strips, each eleven inches long.
Connect
the ends of the strips with tape. (Strapping tape is best, but any tape will
do.) You will have now a strip 121 inches long. Look in the bird guidebook to
find the wingspans of various birds. Then, start at one end and use a yardstick
or measuring tape to mark the tape with the width of each bird's wingspan. Here
are some of wingspans on my tape: emperor penguin, 32 inches; peregrine falcon,
3.5 feet; red-tailed hawk, 4.5 feet; flamingo, 5 feet; turkey vulture, 6 feet;
golden eagle, 7 feet; bald eagle, 8 feet; California condor, 9.5 feet. You can
add the wingspans of any birds you like.
Ask two people to hold the ends of
your tape. Then you can measure your wingspan. When you are not using the tape,
it folds up like an accordion.
Keeping
Warm Through Thick and Thin
Large
objects gain and lose heat more slowly than small objects. Animals with large bodies warm up and cool
down more slowly than smaller animals. They have less surface area in relation to their size than smaller
animals do. For example, a crocodile’s
huge body helps it retain body heat longer than a smaller reptile could. This lets it remain active even after the sun
has gone down.
Activity: Cooling Thermometers
This
experiment is a simple demonstration comparing the length of time it takes for
objects of two different sizes to cool down in your refrigerator.
You will
need: 2 household thermometers, 4
washcloths, rubber bands, paper and pencil, a clock.
Look at
the thermometers and write down the room temperature. Wrap one thermometer in
one washcloth and fasten it with rubber bands. Wrap the other thermometer in three washcloths and fasten with rubber
bands. Put both thermometers in a
refrigerator for five minutes. Then take
them out, unwrap them, and look at the temperature on each thermometer. Which one cooled off the most?
These
activities can be done at home or at school. I enjoy doing the wingspan
activity during my presentation when I do author visits at schools. Third graders are almost always red tailed hawks. Two students together, fingertip to
fingertip, have the wingspan of one bald eagle!
For more projects
and activities go to my website www.carolinearnold.com
or my blog www.carolinearnoldart.blogspot.com.
Posted by Caroline Arnold, author of Too Hot? Too Cold?, due out February 2013.
