The hypothalamus sends signals to the pituary glands. The hypothalamus releases dopamine, so I think dopamine is a good answer?
Answer:
because they reduce interspecific competition
Explanation:
Narrower niches are known to be more specific and limited compared to broader niches, which are generally less specific and less limited. The species that live in broad niches are named generalists because they are able to withstand different conditions. A narrow niche is often correlated with reduced overlap and thus tends to reduce interspecific competition. For example, coral reefs consist of a wide variety of species (including anemones, sea sponges, sea fans, brain corals, etc) which have narrow niches, thus showing high biodiversity.