Brown Tree Frog

The photo is a brown tree frog sitting on my hand.

The farm is home to a host of amphibians. With the recent rains we hear a cacophony of lustful toads and frogs singing all night. Among the most commonly seen amphibians are the tree frogs because they roost under house eaves and on tree trunks and are easily seen.

Recently I’ve seen several brown tree frogs. I’d never seen this color before and wondered if it was a different species. We are in the range of four species of native tree frogs, the American Green Tree Frog (Hyla cinerea), the Squirrel Tree Frog (Hyla squirella), the Gray Tree Frog (Hyla versicolor), and the Tetraploid Gray Tree Frog (Hyla chrysoscelis). The latter two are virtually indistinguishable and can only be reliably identified by chromosome count; H. chrysoscelis has twice the chromosomes of H. versicolor. I searched the records for introduced species and found nothing. So, the brown frogs represent a new, unidentified species or are a color variation of one of the other species.

I’m pretty sure after examining them the brown frogs are not brown gray tree frogs of either flavor. That leaves H. cinerea or H. squirella. I’ve found references online indicating that both H. cinerea and H. squirella can be brown, so I’m assuming the brown frogs are one of these two species. I lean toward H. squirella based primarily on behavior. H. cinerea is a sessile, very inactive frog. When it jumps it goes from sitting still to jumping. It rarely crawls. H. squirella on the other hand is a very active crawling frog. It reminds me of Gollum from Lord of the Rings. The brown frog moves just like H. squirella.

I’m not a taxonomist and have no particular expertise concerning amphibians, so I’m not at all certain and am open to opposing views. Have any?