Page 228 - The Miracle of Migration in Animals

THE MIRACLE OF MIGRATION IN ANIMALS

nocturnal restlessness at the appropriate times of the year—spring
and autumn. Even though they had no natural environment to re-
mind them, some program in their bodies prepared them for migra-
tion. The scientists concluded that this behavior was
pre-programmed.
b) 97% of the captive birds began their activity at the same time
as birds in nature set off.
c) Different bird species subjected to the experiment showed dif-
ferent levels of activity, appropriate to their own migratory behavior.
For example, birds migrating over longer distances showed activity
over longer periods.
d) Crossbreeding trials showed that the quality of migratory ac-
tivity is population-specific and pre-programmed, or genetic.
Furthermore, birds in the experiment changed direction from
southwest to south at the time when they would be expected do so on
their normal migration crossing the Mediterranean near Gibraltar.
Accordingly, birds have a mechanism that tells them not only how
long the migratory activity will last, but also at what point in the mi-
gratory journey they must change direction.
Today, scientists agree that these exceptional skills are pre-pro-

grammed in birds, as is related in an article in Science magazine:
There is good evidence that young birds are equipped with endoge-
nous migratory programs, which tell them roughly how many days
and/or nights that they must fly, and in what direction. 71
Just as other researches revealed that penguins used the Sun to
navigate, scientists also discovered that penguins have a biological
clock that is adjusted in accordance with their original location. So the
Cape Crozier penguin migrated according to Cape Crozier time. In
addition, they discovered that young penguins were just as adept at
navigating as the adults, meaning that penguin chicks are born with
this knowledge. 72

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