Page 18 - The Miracle of Migration in Animals
P. 18
THE MIRACLE OF MIGRATION IN ANIMALS
sea, they have to keep constantly on the move. Their success in doing
so lies in their ability to gauge the tides. As the water level rises, the
larvae move up and down again as the tide goes out, to stay in the es-
tuary. To perform this seemingly simple operation, the larvae need an
important piece of information.
The times of high and low tide are 50 minutes later every day.
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