I am not sure what you mean. Do want the answer to be something like: a trait of birds? A bit of clarification would go a long way in answering this question. My best guess is 'something birds do.'
drive
Ospreys can be found in every continent except Antarctica and is heavily populated in North America (migrating to South America in winter) and Europe (migrating to Africa in winter).
Birds survive in the winter by migrating south for the winter to stay warm when spring comes around they migrate back.
Swallows fly south in autumn also known as migrating.
Some blue jays will migrate south for the winter. But some will also stay in the cold north. It seems that they alternate seasons, migrating one year and staying the next and then migrating again the next year.
By migrating south in the winter, the butterflies are able to avoid cold weather.
Turkeys are not migrating birds because they can not fly ant have enough fat in their bodys to survive the winter.
so they can stay warm for the winter.
If they are non migrating they stay where they are. They don't migrate.
Migrating
Black-winged stilts in many areas do not migrate at all, or go to the nearest ocean coastline. Migrating birds go south of the Sahara Desert in Africa.
In Winter they congregate in a forest in Mexico and in summer the migrate north over the continent of North America in spring, breading as they do so. Then in the Autumn the descendents of the migrating population fly South to their winter roost.