Migration of the Wood Thrush

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Migration of the Wood Thrush
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• Every spring the Wood Thrush song birds take
  flight from their winter home in Costa Rica to
  live in their summer home in Maryland. What
  makes a tiny little bird fly thousands of miles
  year after year?

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First lets talk about what migration is

• Migration is the travel from one place to
  another.
• Birds usually migrate to find food. (not because
  they cant live in the cold or extremely hot
  weather)

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Triggers for Migration

• Seasonal changes
• Change in length of day light.
• Pressure changes

• Scarcity of food
• Changing weather

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Hours of Migration

• Large birds (Hawks, geese, ducks, etc) migrate
  during the day.
• Small birds like the Wood Thrush migrate at night
  to stay clear of the their larger preditors.

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How long do they travel

• Most of the Birds in America fly to their winter
  homes in Mexico and Central America
• The Wood Thrush spends about 6 to 8 weeks of
  traveling to Costa Rica

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Are there Dangers?

• Migration is very dangerous!
• Most birds fly at an altitude of 500 to 2,000
  feet.
• There are natural dangers (storms, predators) and
  man made dangers (habitat destruction, airplanes,
  tall buildings,)

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Are there Helpers?

• Birds use these clues to help them find their
  way
• star patterns
• earth's magnetic field
• landscape features (such as mountain ranges,
  rivers, coastlines)
• wind patterns

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So if Migration is such a big hassel why do it?

• Migration is a ancient phenomena
• It helps keep populations surviving when there is
  inadequate food source available or when a
  certain food source is needed. Example the W.
  Thrushes Fatten up on tropical berries and seeds
  in the winter, and they feed their young insects
  they find in Maryland.

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Evolutionary Benefits

• Migration aids in the process of natural
  selection.
• Natural Selection is the force behind evolution.
• Migration ensures that the strongest individuals
  will live long enough to reproduce, therefore
  producing a new generation of strong birds.

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El Fin

• Hooray the Wood Thrush made it to Maryland!