What is the advantage of seasonal migration in butterflies and birds?

weather, which is why they migrate during certain times of the year.

Explanation:

answer; the above statement is (true);

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.