Australian Ground Frogs: Limnodynastidae

Physical characteristics: Also known as the painted burrowing frog, the painted frog is tan, yellow, orange brown, or gray with dark brown or black spots and blotches on its head, back, and legs. The upper body is almost completely covered with small, rounded warts. The frog has short but not thin front legs and longer hind legs. On the toes of each back foot, it has a black bump that it uses as a shovel, or spade, for digging. This bump, which is called a tubercle (TOO-ber-kul), gives the frog another common name, the mallee spadefoot. (A mallee is a shrubby area where a type of eucalyptus grows.) The painted frog has a short head with a rounded snout and two large eyes with vertical pupils. Males and females look similar except during the breeding season, when the males develop tiny spines on top of their warts, giving them a prickly look. Adults grow to 1.8 to 2.3 inches (4.6 to 5.8 centimeters) long from snout to rump.

Geographic range: Painted frogs live in south-central Australia, including South Australia, and likely Victoria and New South Wales.

The painted frog lives in an area that typically has a very dry season and a rainy season. During the dry season, it stays underground in open forests or shrubby areas. In the wet, breeding season, it is found in grassy marshes, small ponds, and various pools of water. (Photograph by Harald Schüetz. Reproduced by permission.)

Habitat: The painted frog lives in an area that typically has a very dry season and a rainy season. During the dry season, it stays underground in open forests or shrubby areas. In the wet, breeding season, it is found in grassy marshes, small ponds, and various pools of water.

Diet: The painted frog probably eats insects and other invertebrates, but scientists have not studied them closely enough to say for sure.

Behavior and reproduction: At the beginning of the dry season, this frog digs down into the soil. Once in a suitable underground spot, the outer layer of its skin peels up from its body, but stays in one piece and attached to the frog's body to form a coat, or cocoon. Snuggled inside its cocoon with only its nose poking out, the frog enters a state of deep sleep, called estivation, which lasts until the rainy season begins in fall or winter. Once the ground becomes wet, the cocoon splits open, and the frog digs itself out of the ground. The frog apparently does all of its feeding during the rainy season. It also breeds at this time.

Males of this species, which some people call trilling frogs, float in the water and begin calling. The call is a two- or three-second purring or trilling sound. Males and females meet at marshes or other shallow pools, and the females lay clumps of up to 1,000 small eggs in plants at the edge of the water. The eggs hatch into tadpoles, which may grow to be as much as 3.5 inches (9 centimeters) long from snout to tail tip before they change into froglets.

Painted frogs and people: People rarely see this burrowing frog. Those who handle these frogs must wash their hands, because the frog's warts can ooze a gooey slime that is believed to make people sick if they get it in their mouths and swallow it.

Conservation status: The World Conservation Union (IUCN) does not consider this species to be at risk. Although it is not common, its numbers appear to be staying about the same. Some of the frogs live in protected areas, but others live in places that may be developed into farmland, which could hurt the frogs in the future. ∎