Description of a Pacific Tree Frog (Hyla regilla)
The general form is delicate; length about 3 to 5 centimetres, with a flat head and prominent eyes, ear membranes are about one-half diameter of the eyes, parotaoid gland is absent. A fold of skin exists across the breast between the attachment of front legs, fore and hind legs are of moderate length; fingers and toes end in round disks, toes of the hind legs are webbed for half their length, the skin moist and covered with minute tubercles.
The colouration is highly variable; the ground colour can be brown, bronze, green or grey. A dark band is underlined by a lighter stripe usually from the nostril backward through the eye and ear to shoulder. Dark, elongated blotches usually present on the back and limbs and a Y-shaped blotch is often found on top of the head, the two arms extend over the eyes, with the stem pointing backward. The eye has a bronze iridescence. Under parts are whitish and occasionally salmon coloured. Some specimens lack the darker pattern except the dark bank through the eye; all are capable of changing colour to some extent.
The Pacific Tree Frog is readily recognised by the conspicuous disks on the toes and by the dark bands on the cheeks.
In British Columbia it is found chiefly in the south-central and south-western part of the Province, including Vancouver Island and adjacent islands.
Habitat and Habits:
One of our best known amphibians, it congregates in large numbers each spring in almost every pond and swamp and begins a chorus of loud croaking which may be heard a great distance. Only the males croak. In spite of their small size the sound is extremely loud, being amplified by a resonating sac which, when fully expanded, swells the throat to a size three times as large as the head. The individual call appears to consist of two notes, sounding much like the phrase “wreck it”. The croak is repeated at intervals of two or three seconds and may continue through the night and part of the day during the spawning season.
The eggs are laid in February, March, and April on the islands. They usually number twenty to fifty per adult and are enclosed in small clusters of jelly attached to grass stems or other similar supports, often below the waterline. The tadpoles develop rapidly so that on the coast young tree frogs are ready to leave the water by mid-July.
After leaving the water tree-frogs spend most of their life in shrubs and trees. Here they climb with ease, leaping from place to place and clinging to smooth surfaces, such as shiny leaves, by means of the adhesive pads on the toes. Their main food preferences are various insects which they catch with great skill by means of their sticky tongues. The male’s croak at this time is a grating sound not unlike the noise produced by dragging the finger-nail over a few inches of fly screening.
Adult Pacific Tree Frogs eat spiders and a wide variety of insects, which they hunt while climbing about on plants. Tadpoles graze on algae and detritus. In turn, tree frogs are preyed on by snakes, bullfrogs, and many birds and mammals, and tadpoles are eaten by larger frogs and fish.