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.