Daytime green, the polkadot treefrog may have spots of yellow or red.
The Polkadot Treefrog, Hypsiboas (formerly Hyla) punctata, a Kermit lookalike, occurs pretty much throughout South America from Colombia to Argentina and from Bolivia to Brazil’s Caribbean coast. It is also found on Trinidad and Tobago. Swamps, marshes, irrigated gardens, slow-flowing oxbows, and many other moist and wet sites are home to this 1 ½ inch long frog.

In fact, it was about 20 years ago that, in company of several other treefrog species, I met the polkadot species in a water lettuce choked oxbow of Peru’s Rio Orosa. Drawn to the oxbow by the squawks, churrs, and whistles of the frogs, it soon became apparent that the chuckling notes were produced by the little reddish popeyed treefrogs with the Kermit facial expressions. Polkadot treefrogs! I collected a couple to assure that we could all get satisfactory photos (the frogs were returned to the oxbow the next night).

Yes, when found they were reddish with brighter orange dorsal polkadots and a greenish overcast. But they were not that color the next morning! In fact, except for the Kermit-like expression, they looked like different frogs. All were decidedly green, some pale, some bright lime. On some the polkadots had remained orangish, on others the dots were bright yellow. The night to day color change (metachrosis) was remarkable.

But within the last couple of years something more remarkable than mere metachrosis has been accidentally learned. The polkadot treefrog, fluoresces!

As stated in an article by Amanda Ellis: “According to (researcher) Carlos Taboada and colleagues the fluorescence intensity represents about 18−29% of the luminosity under twilight conditions and is suspected to play a possible role in the communication, camouflage and mating of the frog.”

Be this as it may, Patti, Jake, and I have seen hundreds of polkadot treefrogs at dusk and later and we have never noticed any indication of fluorescence under natural light. Now I’m really wondering about my field acumen.