Fall migration is also staggered, as birds head south when the breeding season is over.

The birds are heading north for the summer.

Patrick waited until the birds quit honking and headed back toward the water.

The birds are beginning to turn and are heading once more toward the south.

When winter snow and ice cover the breeding grounds the birds head south to Britain.

He got a good look before the bird, under assault by crows, headed back out to sea.

The bird flew over a grassy field and then headed back out over the Atlantic.

The birds headed southeast in the direction of the Deadly Desert.

What makes migratory birds head south each winter, or how some animals know when to hibernate are among the questions answered.

The second bird was breaking through the cloud and heading for the Flying Lab.