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Why Migrate North?
A Globe-toss Game to Explore Landmass

Which hemisphere has more land? In this globe-toss game, students compare the landmass of the Northern and Southern Hemispheres. They discover that North America is a huge landmass. The United States and Canada provide habitat that is seasonally available for hummingbirds and other migrants.
globe-toss game
Students in Mexico play the Globe Toss game!

What you'll need: An inflatable globe or a spinning globe

1. Land or water? If you have an inflatable globe, stand in a group. One student should toss the globe to someone else. The catcher should look at where his or her right-hand index finger lands. Is it on water or land? Put a mark on the board in one of those two labeled columns.

(If you have a spinning globe, have one student spin it, with eyes closed, and move a finger up and down next to the globe. After 5 seconds, someone says "stop" and the student puts his or her finger on the globe.)

2. Land or water? Your conclusion. After 20 tosses (or spins), tally your results. What can you conclude about the amount of land on Earth compared to the amount of water?
(About 75% of Earth's surface is covered with water. Only 25% is covered with land. What percentages do you get from your numbers?)

3. Where is the land? Look down at the Northern Hemisphere from the north pole (top of the globe). Next, flip the globe and look at the Southern Hemisphere from the South Pole.
Ask: Which hemisphere has more land?

Give Students time to compare the two hemispheres on the globe.

The Northern Hemisphere from the North Pole
The Southern Hemisphere from the South Pole

* Challenge students to use the results of the game and these maps of the hemispheres to explain why most migratory birds head north to breed. Think and Discuss!

4. Math Extension: Measuring Landmass in Each Hemisphere

Did you notice that the Northern Hemisphere has more land mass than the Southern Hemisphere does?

The blue shows the land mass in the Northern Hemisphere. (Click to enlarge.) The blue shows the land mass in the Southern Hemisphere. (Click to enlarge.)
Maps: National Center for Atmospheric Research

Try This!

  1. Enlarge the first map. Use the grid (latitude and longitude) lines to estimate the square units of land (in blue) in the Northern Hemisphere.

  2. Enlarge the second map. Use the grid (latitude and longitude lines) to estimate the square units of land there.
    Note: 97% of Antarctica (covering the south pole) is always covered in thick ice and snow. You can leave that out when counting square units.

  3. How do the land masses in the hemispheres compare? What is the ratio of land to water in each hemisphere?

    Ratios: Land and Water
    Northern Hemisphere: for every 1 unit (e.g., square mile) of land, there are . . . 1.5 units of ocean.
    Southern Hemisphere: for every 1 unit of land, there are . . . 4 units of ocean.
    The Earth's entire surface is about 3/4 water and 1/4 land!