tungara frog, (Physalaemus pustulosus), terrestrial, toadlike frog common in moist, lowland sites from Mexico to northern South America.
The frog is cryptically coloured, its rough brown skin matching the leaf litter in which it lives. Although a mere 25–35 mm (1–1.4 inches) in length, this small amphibian consumes a wide range of insects; unlike many frogs of its size, it does not specifically feed on ants.
The breeding behaviour and calls of the tungara frog have been well studied. At the onset of the wet-season rains, males seek out small, shallow pools. From the pools, they begin calling at dusk, producing a series of clucks, glugs, mews, and whines. This attracts other male and female tungaras to the site, but it also attracts predators such as snakes, opossums, bats, (see rainforest ecosystem sidebar, “Singing a Different Tune”) and other frogs. Calling males can be seen floating on the water, their vocal sacs inflated on both sides of the body. Some males initiate the chorus and call persistently; others only answer, and some remain silent.
After mating is initiated, the female carries the male to a nesting spot, generally somewhat removed from the calling site. There they spend up to an hour and a half constructing a nest: the female lays a combination of eggs and jelly, which the male collects with his hind feet, fertilizes, and whips into a foam mass the size of a fist. These foam nests float on the water and may have 100–200 eggs within them. The eggs hatch before the end of two days, and the brown, nocturnal tadpoles descend from the foam into the water, where they will eat detritus. If the pool has dried, the tadpoles will aggregate beneath the foam, where they can survive for up to five days. Tungara frogs may reproduce two to three months after metamorphosis. Tungara frogs belong to the family Leptodactylidae.