Pacific Tree Frog — Part 3

Hyla regilla Baird and Girard

The eggs are laid in February (Feb. 12th, Carmel, Cal. L. S. Slevin, Collector.) and later. They are small (1 mm. diameter) and are in clusters of from twenty to fifty. The clusters are attached to grasses and leaves in the shallow water. (Fig. 167.) The tree frogs themselves may be found either in the water or under stones and leaves nearby, depending on the temperature of the day.

Hyla regilla breeds in shallow ponds at Seattle, Washington, in late February, at the same time that Rana pretiosa is laying its eggs. The breeding-time begins earlier in southern California; the metamorphosis may be completed in April. The young tree frogs are small (1/2 inch long), but show the typical pattern on the head and back as well as the dark and light parallel bands on the sides of the head.

This tree frog is hardy. In captivity it hides during the greater part of the time, under moss or leaves. It eats small earthworms and beetle larvae from acorns and chestnuts, with the usual eagerness displayed by members of the group.

It frequently sings in captivity, usually from under cover of moss or ferns. The call reminds one of that of Hyla pickeringii, in that it consists of a series of short untrilled notes. It differs in pitch and quality from that of Pickering's frog. The pitch is relatively low, about G of the second line; the quality is harsh, often grating. The throat-pouch is yellowish brown when distended; it is much broader than deep, and when fully inflated is at least three times as large as the frog's head. This Hyla very often sits with the vocal pouch partially distended, the small bag palpitating with the breathing movements. Sometimes, when taken in the hand, the frog will swell the throat and give the call which sounds like the harsh sound made by various mechanical toys. When greatly annoyed or when injured, this tree frog, like Hyla versicolor, gives out a milky secretion from the skin of the upper surface of the body.

Hyla regilla is an attractive little frog. It is delicately formed and beautifully coloured. Besides the colouring already described, it shows much iridescence. Various parts shine with gold and bronze; the iridescence is marked in the region below the eye and on the shoulder and upper arm.