True Frogs: Ranidae

Physical characteristics: As its name suggests, the micro frog is tiny. In fact, they are some of the smallest frogs in the world. Adults reach just 0.4 to 0.7 inches (1.0 to 1.8 centimeters) long from the end of the snout to the back of the rump. Their hind legs are fairly short and end in long-toed feet. The front legs are short and thin. The toes have some webbing between them, but the very long fourth toe on each rear foot is mostly free of webbing. These frogs come in several different pale or dark colors, including green, tan, reddish brown, gray, and black. A dark stripe runs from the eye to the front leg. Many frogs have a noticeable, but thin, light-colored or greenish line that starts at the snout and continues over the top of the head and down The male and the female look very much alike. The male, however, has a large vocal sac that covers half of his underside. The vocal sac is usually not noticeable unless the male is calling. (Illustration by Jacqueline Mahannah. Reproduced by permission.) the back to the rump. Some micro frogs also have dark patches low on their sides and dark-colored speckles on top of the back and head. The back and top of the head have a few, small, scattered warts. The underside of the frog is smooth and dappled with black and white. Sometimes the underside is pale-colored without the black-and-white pattern. The eyes are large and brownish, and the snout is short and slightly narrower toward the front. The male and the female look very much alike. The male, however, has a large vocal sac that covers half of his underside. The vocal sac is usually not noticeable unless the male is calling. To make his call, he blows up the vocal sac to a size almost as big as his entire body.

Geographic range: The micro frog lives at the bottom of Africa in southwestern Cape Province, South Africa.

Habitat: It makes its home in rotting plant roots of shrub-filled woodlands near small pools that fill with water only during part of the year.

Diet: Scientists are not sure what it eats, but if it is like other small frogs in its family, it probably eats small insects or other invertebrates.

Behavior and reproduction: Scientists know little about this frog outside of its breeding season, which runs from June to July. When they are ready to breed, the males sit in the water along the edge of the pool. There, hidden among plants that grow in the shallow water, they call with about half of their bodies above the surface. Each male calls with a one-second long scratchy noise that sounds like "tschik," which they repeat five or six times. Females follow the calls, and a male and female pair off. The female lays about twenty eggs, each of which is small and coated with gel. The eggs stick together in a clump and attach to underwater plants. The eggs hatch into tadpoles. They continue to grow in the water for the next six or seven months. In December, when they have reached about 1 inch (2.5 centimeters) long— 70 percent of which is tail—they turn into baby frogs.

Micro frogs and people: People rarely see this tiny frog.

Conservation status: The IUCN considers this frog to be Critically Endangered, which means that it faces an extremely high risk of extinction in the wild. It lives in a very small area and does not do well around humans. People are, however, moving closer to the frog to construct homes and enlarge their farms. In addition, they are draining water from the wetlands where the frogs breed and have introduced new plants, which are also using up water. ∎