Look at Wind and Monarch Migration
drive to migrate is strong. One September afternoon in Iowa, biologist
Dr. Royce Bitzer watched how wind affects monarchs as they fly. Unless
the monarchs stayed close to the ground, he noticed, the wind carried
many in the wrong direction.
wind was blowing from the southeast at 13-18 mph. Yet
quite a few monarchs were being forced westward if
they got more than 6 to 8 feet above the ground. But the ones that stayed
low were making their way south-southwest to southwest. It
seemed that day as if there was a definite boundary layer near the ground
within which the monarchs could make their way south, but if they rose
above that level, they would end up struggling and getting blown off
course," he observed.
Strong is the Wind Today?
can learn how to read the speed of the wind by watching its effects.
How strong is the wind when leaves rustle, trees
toss, or dust flies?
It's hard for us to imagine the importance of wind in the daily life of
a butterfly. We're so heavy. Only the most powerful winds on the planet
could carry us away. A butterfly, however, weighs about as much as a scrap
of paper its size. Consider this:
Many Butterflies in a Piece of Paper? If the average monarch
butterfly weighs 500 mg, how many could you cut from one sheet of paper?
(Assume the paper measures 8.5 X 11 inches). Describe how you solved
the problem as part of your answer.
the math yourself.
see how we solved the problem. >>