A Little Bit More
Most members of the grouse family live in cold climates and grow “snowshoes” in the fall and early winter. While the ptarmigans (TAR-mih-gans) grow a dense mat of stiff feathers on their toes, most of the other grouse grow numerous 2-3mm projections along each toe, like the teeth on a comb. The additional surface area created by these projections provides the birds with enough support to reduce the depth to which they would otherwise sink.
The Ruffed Grouse is probably the best known of our grouse species and ranges from Alaska to Newfoundland and as far south as Georgia. Males are known for their courtship displays on forest logs each spring as they drum to attract females. During courtship, male Ruffed Grouse beat their wings, producing a low drumming sound that carries great distances through the woods. The drumming has often been described as sounding like a distant tractor starting up, with slow wing beats that speed up toward the end of each roughly 5 second series. Actually, the sound is so low and soft that you may not be sure whether you’re hearing or feeling the drumming; if you haven’t had the sound pointed out to you, you may never even realize it’s a bird you’re hearing. That subtle, low-pitched sound has an advantage: low frequencies travel much farther than do high frequencies and that’s important in thick, forested areas.
Although grouse usually travel on the ground, their flight is strong and rapid when necessary. Any grouse hunter can tell you about their explosive, powerful takeoffs. It is a power they can’t sustain for long, but it’s enough to startle most predators long enough for them to make a hasty escape.
Definitions
Attire: clothing
Activities
Surface Area Matters
Objectives: Better understanding of surface area
Materials: Paper, scissors, bowl of water
This is a simple enough exercise, maybe even a bit crude, but one that may help students understand the concept of surface area discussed in the poster.
1. Take a sheet of paper and cut out a 2” square
2. Fill a medium-sized container with water that is at least 2” deep.
3. Take the 2”square and place it in the water so it becomes completely soaked.
4. Pick up the paper square between your forefinger and thumb and place the square on edge at the water’s surface and gently allow it to slide through your fingers into the water until you are simply keeping it from falling on its side, not holding it up.
5. Once the paper has sunk as far as it will go, note how deeply it sank – it will probably sink to the bottom of your container.
6. Now pick up the square again and place it broadside on the water and note how far it sinks, or doesn’t sink, into the water.
7. It should be immediately apparent that the piece of paper that entered the water “on end” sank to a greater depth than the piece that was allowed to lie flat on the surface. The larger surface area of the “broad-sided piece” was enough to hold the paper at the surface, the minimal surface area of the “on edge” piece could not support the weight of that piece of paper.
Key Concepts
Adaptations and Diversity, Structures and Functions
Questions
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