Anderson's Hyla — Part 2

Hyla andersonii Baird

The specimen photographed moulted the skin February 10th. For several hours before the moult the skin was very dry and lustreless, and the frog kept rubbing one hand and then the other over the head and eyes, as if in discomfort. The skin was thin and white. It was shed in one piece and swallowed as it was shed, in just the manner described for the similar process in the toad and frog.

This Hyla differs conspicuously from Hyla versicolor and Hyla regilla, in fact from most of its nearest relatives in North America, by the fact that it has apparently but a limited power to change colour. The green may pale or deepen, it may even take on a tinge of brown; the lavender tints of hand and foot may be extremely light, or so dark that they become a deep purplish brown. But when we compare this with the radical and rapid changes in Hyla regilla and others, the limitation is very evident. As far as observed, the pattern of dress is never obscured.

Hyla andersonii is an agile climber, but ascends largely by clasping the hands and feet around the support. The adhesive power of the disks is relatively not great, and the under-surface of the body does not seem to aid them as much in climbing as it does many tree frogs. On a relatively smooth vertical surface up which Hyla cinera, versicolor, pickeringii, regilla, and many others will climb rapidly and with confidence, Anderson's Hyla holds itself with great difficulty, even for the space of a few seconds.

The call of the specimen that was found June, 1888, is described as made up of a shrill note repeated three of four times in succession. Those discovered in June, 1889, were found during and preceding a thunder storm, clinging to the under sides of pine twigs in a swampy thicket. Their throats were swollen in the manner characteristic of the Hylas, and before the disturbance came, their voices made part of a chorus that emanated from all parts of the swamp. The single note was compared to that of a guinea-fowl, or of the rail.

Hyla andersonii is certainly rare, and, as far as discovered, has an unusually limited distribution. However, it is probable that the apparent limit of range, and the seeming scarcity within this range, are due, in part at least, to the retiring habits of the tree frog, and in part to the inaccessible character of its chosen haunts.