What is interesting is the Gray Treefrog is actually two different species that are physically identical, the Eastern Gray Treefrog and the Cope’s Gray Treefrog. They can sometimes be told apart by their calls, but they are similar enough that confusing the two is easy. The only sure way to tell them apart is a genetic test. The Eastern Gray Treefrog is tetraploid (four copies of each chromosome) while the Cope’s Gray Treefrog is diploid (two copies of each chromosome). It makes for an easy genetic test to tell them apart, but it leaves field observations almost impossible to sperate them. I do not know which species is in this picture.