Page 104 - The Miracle of Migration in Animals

THE MIRACLE OF MIGRATION IN ANIMALS

The Direction-Finding Expertise of
Butterflies

Migration of butterflies and moths may be seen insignificant,
but their migrating swarms sometimes number in the millions—and
under some circumstances, it takes a few generations to complete the
migratory circuit. Temperate-zone butterflies tend to migrate to find
feeding grounds, while tropical butterflies like the monarch migrate
towards the rainy regions that suit their needs. 33
The average life span of temperate-zone butterflies is between
three and four weeks. Yet in the course of their short lives, they some-
times travel from one country to another, and sometimes leave it to
other generations to complete the intercontinental migration.
Migrating flocks can consist of millions of butterflies. These lovely

brightly-colored insects, each species distinguished by different wing
patterns, use an interesting method to find their way on the journeys
that are a natural component of their lives.

How Do Butterflies Find Their Way?

In the temperate zone, there are few areas with flowers for but-
terflies to feed on, so these delicate little insects must migrate to reach
their best feeding grounds. They will fly in a straight line to a flowery
meadow, but on arriving they change their behavior and act as
though they live there. They feed from the flowers, mate, and the fe-
males lay their eggs. But their idyllic meadow life lasts only a short
time. Within a few minutes or several days, the butterflies leave the
field.
Butterflies migrate only at the hottest times of the day and then

only when the Sun is shining. When the Sun is at its brightest, they

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