A male Barker, content and vocalizing.
We have in the southeastern USA a treefrog, Hyla gratiosa, that is not only large, but is capable of chameleon-like color changes, and that when vocalizing from a flooded ditch or woodland pond has a call that is unmistakeable. Then it is an oft repeated, loud, hollow-sounding, “woooook.” However, while waiting in the warm weather for breeding sites such as ditches and vernal ponds, to be filled by spring and summer rains, this treefrog may ascend high in woodland trees and produce a very different sound, one that is more like a “whirrrrr” than a “woooook.”

As mentioned, Barkers (they’re called this by many) are capable of rather rapid color changes. When “content” such as when inflated and floating on the water surface, often while holding on to an emergent or floating plant stem or sitting on a grassy shallow, they are of some shade of green and have very visible rounded solid or open-centered dorsal spots or ocelli. These may be darker or lighter than the frog’s dorsal ground color. If stressed or for other reasons known only to the frog, the green may quickly become gray or brown, again with or without very visible dorsal spots or ocelli. There is often a white labial and lateral stripe and the belly is usually dark with irregular light spots.

When adult Barkers are of heavier build than most other treefrogs and are also larger, usually being 2 to 2 ½ inches svl (snout-vent length). The skin appears granular.

Most common on the southeastern coastal plain and lowlands from extreme eastern Louisiana to central-eastern North Carolina, there are disjunct populations in more northerly states.