Several species of frogs live in the bog at the end of marisa's road. almost any night you can hear them croaking. this spring they seem to be less noisy. what change in the frog's environment could have affected their population?

Reduction of the size of the population

Explanation:

If they are less noisy, the size of the population might be lower. The possible reason for this may be an environmental alteration which has reduced the amount of individuals (for example: more predators, less food, polution in the water, between other reasons)