An ecologist studying communities would study which of the following? a. the development of males' mating dances in a particular species of spider. b. changes in the size of a mouse population after hawks, a main predator of mice, are introduced into the area where the mice live. c. changes in the abundance of a particular species of frog in a portion of a rainforest over time. d. the effects of soil erosion on plant species found on the side of a mountain

B. Changes in the size of a mouse population after hawks, a main predator of mice, are introduced into the area where the mice live

Explanation:

A community is defined as a group of populations of two or more different species which inhabit the same area at a certain time.

Community ecology is the study of the interactions between species in communities through time on a certain place. It includes the study of the distribution, structure, demography, and interactions between populations.