Some seabirds spend all or most of their lives in very cold waters. Pigeon Guillemots live and breed in the North Atlantic and Arctic Oceans, while penguins chase fish and krill on the other end of the globe in the frigid Antarctic Ocean. How can they do that without freezing?
To find out, be a scientist and conduct an experiment. You can do this one right in your kitchen. Here’s what you’ll need:
- ½ to 1 cup shortening (e.g., Crisco or another brand), margarine, or other soft cooking fat (Note: Liquid cooking oil will not work)
- Zipper-closing plastic freezer bags, quart-size
- Duct, packing, or other strong tape
- Large bowl, plastic tub, or a sink with a stopper
- Measuring cup and rubber spatula
- Cellphone timer or clock with a second hand
Kids will make a “blubber mitten” to represent the insulating effect of a layer of fat (blubber) in the bodies of seabirds that live in icy waters. They’ll also make an uninsulated (blubber-free) mitten for comparison. You’ll need to guide and supervise children through these steps.
- To make the “blubber mitten,” scoop enough of the soft fat into one zipper-closing freezer bag and move the fat around so that it coats all of the inner surfaces of the bag. Try to keep the zipper closing free of the fat. Turn another freezer bag inside out and put it inside the fat-filled one. Since the inner bag is inside-out, you are able to zip the closings of the two bags together so they are attached to each other. This leaves the inner bag open so that a hand can be placed inside. Add duct tape or other tape to the seals to prevent water from entering.
- Make an uninsulated mitten to represent a bird’s body that is not adapted to cold-water survival, such as a robin or cardinal. Place one inside-out freezer bag into another and zip and tape them together—no “blubber” in this one.
- Fill the bowl, tub, or sink with water and ice.
- Explain to the children that they will put their hand into each mitten (fat and no-fat) and place it into the cold water and hold it there as long as they can until the cold makes their hand hurt. Ask them to predict which mitten will let them keep their hand in the longest. (This is their scientific hypothesis.)
- Place the “blubber-free” mitten over a child’s hand. When you say “start,” have the child plunge the covered hand into the icy water. Start the timer or note the time. Tell your child to keep the hand in the water as long as possible until it hurts from the cold, then take it out. Check the time when the child pulls out the hand and write down the number of seconds.
- Now place the “blubber mitten” on a child’s hand. As before, when you say “start,” have the child plunge the covered hand into the water while you start the timer or note the time. Again, tell your child to take the hand out of the icy water as soon as it begins to hurt. Write down the time too.
- Compare the two numbers and discuss the results of your scientific experiment. Were the children’s predictions correct? Why do they think the “blubber mitten” protected their hand longer? How does this relate to seabirds? Here’s the answer: Seabirds that live in icy waters have a layer of fat that insulates their bodies against the effects of the very cold water.
- Be sure to wash and re-use the plastic bags!
Audubon Adventures is an environmental science curriculum, developed by professional educators, that presents standards-based science content about birds and their habitats. It includes four-page magazines (in PDF format) just for kids with lively content, illustrations, and photographs on a variety of topics. Explore more activities, games, and lessons about birds and nature at the Audubon Adventures website.