Introduction

Hyla - hyle is Greek for wood or forest

chrysoscelis - from the Greek word chryso for golden yellow colour and coeli for abdomen or belly

versicolor - from the Latin vertere meaning to turn or change, referring to being changeable in colour

Their calls are the only external characteristic distinguishing these two species.

Though they only grow to a maximum of 6 cm, grey treefrogs are the largest of the tree frogs in Canada. There are two different species of grey treefrogs, Hyla versicolor and Hyla chrysoscelis, but they look very similar. The two species are differentiated by microscopic examination of their red blood cells, as the tetraploid frogs have much larger cells. The mating calls of the grey treefrogs are also distinguishable, but they live in the same habitat and their behaviour is similar.