ability to fly allows them to travel long distances. They can do
this more quickly, more safely, and using less energy than animals
that have to walk. That is why so many different kinds of bird migrate.
Some insects migrate too, even though their smaller size makes the
journey more difficult. Among non-flying land animals, only a few
undertake long-distance migrations. They are usually large mammals
such as the caribou.
do birds migrate?
a lot of energy, and it is dangerous. The birds have to pass through
a lot of unfamiliar places. Many die along the way. Food supply
is the main reason birds make such long, hazardous trips. If birds
stayed south all summer, they would have to compete with other southern
birds for the limited supply of food. This would be especially difficult
when it came time to feed a nest full of hungry chicks. By travelling
north in the summer, birds find good habitat with fewer competitors
than there would be if they all stayed in the south.
Not all birds
migrate. Some live in the tropics year-round. Others stay in the
north all year. Birds that don't migrate are those that can tap
into a particular food source that's available year-round. For example,
woodpeckers can dig into the bark of trees where many insects spend
How do birds
up extra body fat, which gives them the energy for the trip. The
fat can be up to fifty percent of the bird's body weight when it
sets out on its migration flight. Most birds stop to eat during
the migration, but they still rely on stored fat to make it through.
It can be hard to find food when travelling through unfamiliar areas.
Some birds fly at night when they migrate. Others fly during the
day. Birds try to use weather patterns to assist their migration
flights. For example, they will wait for a tail-wind before starting
out on migration. This way, they can complete the trip faster and
How do birds
find their way?
Birds can sense
the Earth's magnetic field, and they use a variety of visual clues
such as the stars and land features to help them navigate. Although
many birds have an instinctive urge to migrate, birds learn their
specific migration route the first time they make the trip south
with their parents.
a problem when biologists wanted to establish a new population of
the whooping crane, an endangered species. Biologists were able
to raise the whooping cranes in captivity, but the cranes would
not migrate! Biologists taught the cranes to follow a small, manned
airplane called an ultralight. This plane led the birds on their
thousand-mile journey from Wisconsin to Florida, and after that
first time, the birds knew how to make the trip on their own. more
This bird migrates over 20,000 miles each year, flying from the
arctic to the antarctic and back. No other species travels farther.
Godwit. This bird, related to sandpipers, makes the longest
non-stop migratory flight. It flies 7,000 miles over the
Pacific Ocean from Alaska to New Zealand! The trip takes five or
six days. more
Best-known of migratory insects, the monarch butterfly travels from
the US and Canada to Mexico, where it spends the winter. Individual
monarch butterflies never complete the return voyage. They lay eggs,
and their offspring continue northward to lay more eggs, so by the
end of summer monarchs have repopulated much of the continent. more
The snow goose is famous for congregating in huge flocks during
its migration from the arctic to the southern US. As many as a million
of these beautiful white birds can be seen in one place!
Snow Geese in New York State