Northern green frog

Description:

This is a female green frog. Green frogs are variable in color and pattern, but can be differentiated from similar species - such as bullfrogs and leopard frogs - by the dorsolateral ridges that run from behind each eye to about three-quarters of the way down the back. In leopard frogs, the ridge continues all the way down the back and bullfrogs lack these ridges altogether. Females and males can be differentiated by the size of the tympanum (the eardrum, located behind the eye and below the dorsolateral ridge). In females, it is about the same size as the eye and in males it is much larger than the eye.