First,
look at the sightings that are farthest south
for each date.
1.
To do this, hold your string against the bottom of your computer
screen when you have these words and at least the bottom half of
the map showing.
2.
Slowly move the string up the screen until you come to the first
triangle, or the first dot of each color. Notice where it is. (This
would be an even more accurate method if your string were curved
the same as the latitude lines.)
- Which
state has the most southern wintering report (the first triangle)?
- Where
do you find the first red dot? How about the first pink dot? The
first blue dot? These bottom dots show the southern range of "first
sightings."
What
direction does the migration seem to be moving (e.g., north or
south)?
Next,
look at the sightings that are farthest north
for each date.
Read
these instructions first, and then scroll to see the top half of
the map on your screen. Hold your string on the top of the screen
and move down, looking for the first triangle, and the first red,
pink, and blue dot as you move the string down. After you do
this, come back here and read on.
- Did
you see the same clear progression as you saw when you moved your
string up from the bottom? Probably not. Here's why:
The
very first robins to move are the ones most sensitive to weather,
daylength, and other signs of spring; some robins are
also more restless than others. The birds at either extreme
don't always
follow the "rules"!
Finally,
try to see the clusters of color.
Find
the latitude at which:
*
half the red dots are above it and half below it.
*
half the pink dots are above it and half below it.
*
half the blue dots are above it and half below it.
- Is
the biggest cluster of pink dots a bit north or south of the biggest
cluster of red dots? Where is the cluster of blue dots in relation
to the others?
- What
does this tell you about the general (average) progression of
the migration?
You Are
the Scientists!
By trying to make sense of the dots (data) on this map, you
are thinking like scientists. You are able to "eyeball"
the dots and look for patterns. Scientists might use different
types of graphs and math equations to more precisely analyze
what the data points reveal about the progression of migration.
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Part
3: Final Migration Map for the Year
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