How Bird Migration Works

Why birds migrate

Migration is a response to food and breeding. Following the end of the monsoon, insects and seeds thin out, so many species move to where food is more reliable. The trip back brings them to the nesting grounds they know.

Seasonal movement

Most Indian migratory species arrive on the plains between October and March. Some are summer visitors that breed in the mountains and leave before winter; others winter here and breed thousands of kilometres north.

Navigation

Birds use the sun, the stars and the earth's magnetic field together, and many navigate by remembering landmarks along a route they have flown before.

Challenges

Long flights cost energy. Storms, habitat loss and light pollution all make migration harder, and changing climates are shifting the timing of arrival.