Question

two different types of birds want to build nests in the same hole in a tree. what are they doing? practicing parasitism; cooperating; practicing commensalism; competing

Explanation:

When two species seek the same limited resource (a tree hole for nesting), they engage in a struggle for that resource, which defines competition. The other options do not fit: parasitism involves one organism benefiting at another's expense, cooperation is mutual benefit, and commensalism is one benefit with no harm to the other.

Answer:

Competing