Comparing
Migrations
Why Do Rufous Hummingbirds
Seem Far Ahead?
Last
week (March 2007), many students asked, "How
can Rufous hummingbirds be in Canada already, when Ruby-throats
are still gathered in the southern United States?" Are
the Rufous hummers faster or more eager? Is this just an unusual
year? Let's explore!
-
This map shows the Rufous hummer migration on March 14, 2007.
Look at the leading edge (birds farthest north).
- Roll
your mouse over the map to see the leading edge of the Ruby-throated
migration on the same date.
- What
differences do you notice?
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