Which
Way to Mexico?
Do You Know?
Monarch butterflies
are born knowing the way to Mexico — do you? Guess which way they
should fly and, on the count of three, point in that direction. (Have
each person put a "Post-it note" on the wall, to mark the direction
of their guess.)
Mexico's
monarch sanctuaries are west of Mexico City, at 19N, -100W.
(Click on map to see more.)
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Try
This!
- Take out
a globe and find Mexico's monarch sanctuaries.
- Make and
cut out a small paper "compass rose," with a diameter of about
6 cm. Carefully label north (0 degrees), east (90 degrees), south (180
degrees) and west (270 degrees) on the compass.
- Put the
compass rose on the globe directly above your home town. (To ensure
that the compass shows direction accurately, align its north/south axis
parallel to the longitude lines at your latitude.)
- Place
a ruler on top of your compass and, pivoting from the center of the
compass, look below the ruler until it's lined up to make a straight
line between your home town and the sanctuaries.
- Mark the
place on the compass where the ruler intersects the compass. This reading
is the "bearing" from your home town to the sanctuaries. For
a closer reading, go back and fill in values on the compass to 10 degree
increments.
- Use this
bearing to mark the direction to Mexico in your classroom. Using a real
compass, align it to north. Then take your bearing measurement with
the compass. Draw an imaginary line to the classroom wall and mark the
wall with a monarch carrying a little sign, "This way to Mexico"
or "Mexico or bust!!"
- The next
time you're outside with a real compass, find the direction to Mexico
using your bearing measurement, and then point in the direction of the
Mexican sanctuaries.
- Finally,
the best part: Lie down on your back and watch for migrating monarchs.
Are they flying in the same direction you calculated?
If they're not, don't be surprised! You'll have uncovered one of the
greatest mysteries of the monarch migration.
How
Do They Do It? What Scientists Say
How DO monarchs orient and navigate to a small point on the
globe--to a place they've never been before? Scientists don't
fully understand the mechanisms involved. Read the excerpts
below and have students list factors scientists believe (or
once believed) are involved. Next, ask students to list questions
scientists still have.
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National
Science Education Standards
- Employ
simple equipment/tools to gather data and extend senses. (K-4)
- Use appropriate
tools and techniques to gather, analyze, and interpret data. (5-8)
- Although
men and women using scientific inquiry have learned much about the objects,
events, and phenomena in nature, much more remains to be understood.
Science will never be finished. (K-4)
National
Geography Standards
- How
to use maps and other geographic representations, tools, and technologies
to acquire, process, and report information.
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