Grey Treefrogs (Hyla versicolor) are my favorite frog species at the moment. They are cute little colour changing, antifreeze laden, Lichen-Spirits who really belt it out when trying to find a date. I have been hearing them pretty much nightly lately, screaming their short trill all over nearly every wetland I encounter as long as it is fairly adjacent to trees. Because of their powerful calls permeating my late night waking life, I have been wanting to take a deeper dive. Hope you enjoy!

To learn more :

The Dermal Chromatophore Unit by Joseph T. Bagnara, John D. Taylor and Mac E. HadleyMetamorphosis by Peter B. Mills. Self-published, 2016.
Energetics of vocalization by an anuran amphibian (Hyla versicolor) Taigen, T.L., Wells, K.D. J Comp Physiol B 155, 163–170 (1985). https://doi.org/10.1007/BF00685209
Familiar Amphibians & Reptiles of Ontario by Bob Johnson. Natural Heritage, 1989.Reptiles and Amphibians of Toronto : Biodiversity Series pamphlet (pdf)
Amphibians and Reptiles of the Great Lakes Region by James H. Harding & David A. Mifsud. University of Michigan Press, 2017.
After the Ice Age by E. C. Pielou. University of Chicago Press, 1991.