Question

When we talk about bird migration, what is the word migration referring to​

Answer 1

Explanation:

verb (used without object), mi·grat·ed, mi·grat·ing. to go from one country, region, or place to another. to pass periodically from one region or climate to another, as certain birds, fishes, and animals: The birds migrate southward in the winter.

Answer 2

Answer:

Migration carries high costs in predation and mortality, including from hunting by humans, and is driven primarily by availability of food.