Base your answer to the question on the information below and on your knowledge of biology.

There are two different species of finch that live on the same small island, species A and species B. Both species successfully feed and reproduce on the island. Species A nests in pine trees and eats large seeds. Species B nests in hollowed-out dead logs and eats small insects.

The factor most often acting as a selecting agent for the survival of a species in a particular location is the