Narrow-Mouthed Frogs: Microhylidae

Physical characteristics: The Wilhelm rainforest frog has a dark brown or purplish brown body with yellowish tan spots and blotches on its back and legs. The snout is short and slightly upturned at the end. Its long, thin legs have lengthy toes that are tipped with wide, triangular-shaped pads. This species grows to 2 inches long (5 centimeters) from snout to rump.

Geographic range: The Wilhelm rainforest frog lives in the mountains of Papua, New Guinea, between 6,000 to 9,000 feet (1,900 to 2,800 meters) above sea level.

Wilhelm rainforest frogs may be found in many areas in the rainforest. They often climb high into trees, where they hide away in tree holes or inside plants that grow on the sides of the trees. They may also spend time along the ground, frequently tucked into burrows on the sides of stream banks or other steep areas. (Illustration by Brian Cressman. Reproduced by permission.)

Habitat: This species hides among rainforest trees and in holes along the ground in steep areas, especially on the edges of roads, and sometimes in grass near streams.

Diet: Scientists are not sure what specific kinds of food these frogs eat. If they are like many other members of the family, however, they eat some types of invertebrates.

Behavior and reproduction: Wilhelm rainforest frogs may be found in many areas in the rainforest. They often climb high into trees, where they hide away in tree holes or inside plants that grow on the sides of the trees. They may also spend time along the ground, frequently tucked into burrows on the sides of stream banks or other steep areas. The males call females from inside ground burrows or from hiding spots high in the trees. They mate in either place. Females lay strings of two dozen or so eggs in the burrow or high in the trees. Scientists have little information on their reproduction, but one report noted a string of 27, 0.2-inch (5-millimeter) eggs in a burrow, along with a frog—probably the male—staying with them. Instead of hatching into tadpoles, the eggs hatch right into froglets.

Wilhelm rainforest frogs and people: People rarely see this frog in the wild. It is not common in the pet trade.

Conservation status: The World Conservation Union (IUCN) does not consider Wilhelm rainforest frogs to be at risk. This frog lives in a fairly small area, but the area is in good shape and the frog is quite common. ∎