Green Frogs and Bullfrogs only breed in permanent water bodies. Tadpoles dig into the mud over winter and it takes two or more years to metamorphose into frogs. Frog calls are used to establish populations of certain frogs in an area. Frog populations help gauge our understanding of the overall condition of the environment on land and in the water. Frogs are a marker of water quality because they lay their eggs in water and spend the early stage of their life in water as tadpoles.
Polluted water can kill eggs and tadpoles.
Frogs breathe through their skin so even adult frogs can be affected by polluted water. Frogs hop up to one mile from breeding ponds to feed. Without adequate undeveloped land for frogs to and roam and catch food, the populations can shrink. The following is a chart of which frogs call and when. The next time you hear a frog croak try to figure out which species it is.