WHERE’S WALDO? Find Kitten-Cute Treefrogs for Fun and Science

Photos and Text by Barbara J. Saffir

Look closely. I mean REALLY closely. A hidden treasure that sparked a global study could be hiding in plain sight: mutant blue-colored frogs. And they’re back this summer at Huntley Meadows Park in Alexandria and Leesylvania State Park in Woodbridge—and just waiting to be discovered. Be the first to find these curious critters in your neighborhood or during your travels—for the joy of a rare discovery and to help scientists learn more about their little-understood condition called “axanthism.”

Axanthism, according to The Blue Frog Project, which was published last year, is caused by “changes in diet or genetic mutations [that] can reduce the amount of yellow pigment in skin such that a normally green frog appears blue (axanthic).”  Records of blue frog sightings remained rare—until iNaturalist citizen-science app users like me started documenting them in 2019.

Most of the blue-colored frogs in the DC area are mutated green treefrogs (Dryophytes cinera). The first documented blue frog in our region appears to be by Virginia photographer Mar Acevedo at Huntley Meadows Park on Aug. 31, 2019. After several specimens were posted to iNaturalist, I queried Rayna Bell, a herpetologist who then was working in Washington, DC for the Smithsonian National Museum of Natural History and asked her whether anyone was studying them. That simple query helped prompt her to create the Aberrantly Blue Frogs project on iNaturalist, which eventually sparked the five-year global Blue Frog Project study of the mutant blue frogs, mentioned above. It found “over 300 records of axanthism in 36 species across the frog tree of life by leveraging iNaturalist observations.” The study found far more records using iNaturalist in the last 15 years (when iNaturalist debuted) than in a century of formal scientific literature. Dr. Bell, now Curator of Herpetology at the California Academy of Sciences, and her colleagues are continuing their studies and hope to include some specimens from Huntley. 

Stop by Huntley Meadows Park between mid-August and mid-October and you could find gobs of the little green treefrogs (GTFs), depending on the weather, time of day, and your luck.

If you’re lottery-lucky, you may get to eyeball the blue beauty that is luring more treefrog fans to the popular wetlands park. This year is special because these distinctive mutants are not found every year.

So, what should we know about green treefrogs? They live near water from spring through early fall but sometimes they’ll just pop up on a backyard barbecue or on the windows of houses and other buildings. You can start looking in April when they come out to breed but they’re easier to see in the late summer. (Other frog and toad species can be found starting as early as February in the DC region.)

And what a find they are. To their fans, little green treefrogs are as cute as kittens, as adorable as teddy bears, and as fantastic as fairies. 

And since these charismatic night-hunters sleep most the day and are queens and kings of camouflage, it’s a fun but challenging game trying to find them, like “Where’s Waldo.”  The little creature’s average size ranges from thumb-nail (as juveniles) to about 2.3 inches (as adults), about the length of an average woman’s thumb. And even the “normal” green ones can change from bright yellow-green to olive green to brown, and all shades in between, depending on the weather, their perches, and other conditions. Green treefrogs have sticky feet like their more famous Amazonian cousins, gold eyelids, and white and/or gold “racing stripes.” Each morning, they slumber in the sun to warm up, but when it gets too hot, they usually flip around to the shady side of a leaf or stem where they were hanging out.

Is it worth looking for these enchanted charmers?  Ask ARMN member Manoma Sirisena. She has seen several blue frogs over the past few years. It’s a “surreal experience,” she said. “What’s not to love about treefrogs?” she added. “They have these big, beautiful eyes. I’ve heard people say they look like cartoon characters.” And their presence signals that their habitats are healthy ecosystems.

Green treefrogs live in coastal states from Delaware to Texas and in parts of Arkansas, Tennessee, Kentucky, Illinois, and Missouri. But don’t bother looking for them west of I-95 in Virginia and Maryland because most are found in or near the coastal plain, which is roughly east of I-95.   

If you find a partially- or completely-blue frog, please document it by uploading a photo to iNaturalist, along with the Aberrantly Blue Frogs iNaturalist project. And please share your discoveries with others, too!

Even if you don’t spy the blue superstar, if you look very carefully, you will likely see at least several snoozing green treefrogs and may stumble upon other fun finds.