Though they do not bird migration, many are at least somewhat nomadic.

It is strongly bird migration, with many northern birds moving south during the winter.

It is a long-distance bird migration moving in winter to Indonesia.

They are bird migration and winter in southern South America.

"However, if they are participating in tracking bird migration that is a whole other story."

The area also plays a role in bird migration, serving as a place of rest and nourishment.

A flyway is a flight path used in bird migration.

The principal research focus is on bird migration through banding studies.

Cape May is a great place for bird migration.

The main bird migrations, when a wide variety of species may be seen, take place in spring and autumn.