What kind of frog is this?
Thank you for your question. The angle on this photograph is not the best for identification. I believe this is a Common Gray Treefrog, scientific name Hyla versicolor. There is another similar species, Cope's Gray Treefrog, scientific name Hyla chrysoscelis. They are virtually impossible to tell apart. You can distinguish them in the field based on their mating calls, otherwise the only way to differentiate them is their chromosome count. The Common Gray Treefrog has twice as many as the Cope's Gray Treefrog.
Despite the name, both species are capable of color change. They can be gray, greenish, brown or nearly white. They usually have a white spot underneath each eye, and bright orange or golden yellow coloration on the underside of each hind leg.
They spend most of their time in the trees, but both species descend from the trees to mate in temporary or permanent water bodies.
Here's a link to the Maryland Dept. of Natural Resources' Field Guide to Maryland's Frogs and Toads webpage for treefrogs found in Maryland:
I hope this answers your question, and thank you for contacting Ask an Expert.