Why do birds migrate?

Every autumn, many birds pack their bags, or rather their wings, and set off on a journey of thousands of kilometers. In spring they return to the same place. This great journey is called migration, and it is one of the most amazing feats in nature.

Why they leave

The main reason is food. In winter, cold regions have few insects, fruits and seeds, and lakes freeze. Birds travel to warmer places where they find food all year round.

Why they come back

In spring, the northern regions fill with food and long hours of daylight, ideal for raising chicks. That is why many birds return to the same place where they were born or where they nested the year before.

Record travelers

The Arctic tern makes the longest journey: it goes from one end of the Earth to the other and can travel about seventy thousand kilometers a year. The bar-tailed godwit crosses the Pacific Ocean without stopping, more than eleven thousand kilometers, in almost a week.

How they find their way

Birds use several clues at once: the Sun by day, the stars at night, the Earth magnetic field, rivers, mountains and coastlines, and even smells. Many young birds learn the route by following the adults.

Flying in a V

Geese and cranes fly in a V shape. This way, each bird uses the air moved by the one in front and gets less tired. They take turns at the front to share the effort.

Dangers of the trip

Migrations have risks: storms, lack of food at stopovers, lit buildings and glass. That is why it is important to protect wetlands and natural areas where birds can rest.

A fun fact

Some birds, like storks and swifts, arrive in Spain in spring. Today many storks no longer leave in winter, because they find food at landfills.

Activity: draw a route

With a world map, draw the journey of a stork from Europe to Africa and mark places where it could rest. It is a trip of thousands of kilometers!