Hidden in the Trees and Too Cool To ( Totally ) Freeze
By Assistant Naturalist Jordan Tremper
One of the freshly unfrozen ( and arguably most
adorable ) faces you can expect to see this spring at McCloud Nature Park is that of the Gray Treefrog . We have two kinds of Gray Treefrog in Indiana : the Eastern Gray Treefrog Hyla versicolor , which usually lives north of Indianapolis ; and the Cope ’ s Gray Treefrog , Hyla chrysoscelis , which usually lives south of Indianapolis .
These two species are nearly identical , with the same granular skin texture and yellow patch on their thighs . Their trilling songs are slightly different , with the Cope ’ s Gray Treefrog having a quicker trill than the Eastern Gray Treefrog . They both sing from mid-April through June , so soon there will be plenty of opportunity to hear them near woodland ponds .
Like all amphibians , the Gray Treefrog undergoes metamorphosis . It begins life as an egg that hatches into a tadpole that becomes an adult treefrog — all within 2 months ( presuming it is not eaten ). But growing legs and arms is no excuse to stop growing ! A freshly metamorphosed treefrog just past 0.5 ” can grow up to 2.5 ” long .
Like other treefrogs , the Gray Treefrog has bubble-shaped toe tips that act like suction cups and allow it to climb up grass blades , fence railings , walls , trees , and ( on occasion ) humans . The Gray Treefrog has another special ability : it can change color from gray to green to brown . Combined with the lichen-like look to its skin , the Gray Treefrog becomes a master of camouflage , able to blend in with the bark of any tree it calls home .
If you can see through its camouflage , you might be able to find it through the winter , hidden in logs , leaf litter , tree hollows , or roots . Of course , treefrogs won ’ t be very lively if there ’ s still snow on the ground . Contact with ice triggers the Gray Treefrog to freeze itself — literally ! Until the vernal sun thaws out land and frog alike , these treefrogs may be up to 40 % ice . Most creatures wouldn ’ t survive , but
Above : This Gray Treefrog spent a good deal of the summer singing in the McCloud Nature Center drain pipe . He was almost 2 ” long ! Left : Naturalists found this young adult Grey Treefrog crawling in the leafy undergrowth . It was only about a 0.5 ” long !
the Gray Treefrog floods its bloodstream with glycerol , which acts like antifreeze to prevent the ice from harming the frog .
Like the Gray Treefrog , the Chorus Frog , Wood Frog , and Spring Peeper also become frog-sicles during the winter . Even better , all these frogs ( along with the Cricket Frog and American Toad ) can be heard at McCloud . A few may begin singing as early as March , so if you get the hankering to dance the hokey-croaky , our frogs will have your backup music covered !
Winter / Spring 2021 • 21