Page 164 - The Miracle of Migration in Animals

THE MIRACLE OF MIGRATION IN ANIMALS

Green turtles migrate from the shores of Brazil to mate and lay their eggs on
Ascension Island. The navigational skill of this species astonishes
scientists.

away. Eighty days later, she was found again laying eggs on her orig-
inal nesting beach. Investigation of her ovaries showed that she had
not bred at all in the intervening eight years.
In this time, the turtle had traveled a minimum distance of 5,100

kilometers (3,100 miles). Assuming that her migration began the day
she was caught, she had to cover 32 kilometers (20 miles) a day to re-
turn to her breeding ground. First she would have had to go north-
east to cross the Gulf of Carpentaria, then after passing through
Torres Strait, head in a generally southerly direction. She must have
been exposed to a range of currents, some running with her, and

some against her. If this turtle had meandered at random, she would-
n’t have been able to complete the return journey so quickly. 47

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