Question

why do birds fly south for the winter​

Answer 1

Explanation:

Why do birds migrate? ... Birds that nest in the Northern Hemisphere tend to migrate northward in the spring to take advantage of burgeoning insect populations, budding plants and an abundance of nesting locations. As winter approaches and the availability of insects and other food drops, the birds move south again.

Answer 2

Birds fly south in the winter in search of alternate food sources, and even though their summer home might be nicer, they return home in the spring when their usual food stocks are replenished.