Did
you notice that . . .
1.
Robins winter in many places.
2.
There are many more sightings in the eastern half of the continent
than in the western half.
Why
do you think that's true?
-
There really are more robins in the East. Why? Because
the western states and provinces (except for those on the coast)
get less rainfall. (See
for yourself!) The greater amount of moisture in the East
means good things for robins: more lakes and rivers for drinking
water, more water for fruit-bearing trees, and softer soils where
earthworms thrive.
- Also:
There are more Journey North participants in the eastern part
of North America.
3.
The largest number of robin sightings are along the coasts in the
winter.
Why do you think that's true?
- Look
at this map of extreme
minimum temperatures and this map of extreme
maximum temperatures. Do the coasts or the central part of
the U.S. appear to have less extreme (more mild) temperatures?
- What
did you just learn about robins and moisture?
-
What did you just learn about the locations of Journey North participants?
Center
the map on your computer screen.
Hold a piece of string or a rubber band taut across the screen.
Move it to where half the triangles are above it and half are below
it. At what latitude is the center of the wintering range of robins
in this sample map?
Part
2: Six Weeks Later
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