Ghost Frogs: Heleophrynidae

Physical characteristics: The Natal ghost frog has a brown to black head and back with yellowish to green blotches, and a lighter colored underside with markings on its throat. Like other ghost frogs, its body is flattened a bit, and it has small triangular-shaped pads on the tips of its front and back toes. Its large, bulging eyes have vertical, cat-like pupils.

Geographic range: It lives in the Drakensberg and Maluti moun-tains of South Africa, Lesotho, and Swaziland from 1,900 to 8,776 feet (580 to 2,675 meters) above sea level.

Natal ghost frogs' sticky, wide front and back toe tips help them to climb easily up even the wet and slippery sides of streamside rocks. (Illustration by Patricia Ferrer. Reproduced by permission.)

Habitat: The forests and sometimes the grasslands of the eastern mountains of southern Africa are home to these frogs. As the breed-ing season draws near, they travel 0.6 miles (1 kilometer) or more to reach a fast-moving stream where they mate and have their young.

Diet: Tadpoles are vegetarian and scrape algae from rocks with their small teeth. As adults, Natal ghost frogs eat spiders, small insects, and other invertebrates.

Behavior and reproduction: These frogs usually hide in holes along stream banks and cliffs during the daytime, but sometimes venture out to waterfalls, where they sit in water-splashed areas and look for things to eat. They are most active at night, however, and do the bulk of their hunting then. Their breeding season begins after the heavy spring rains. During this time, the males begin calling from hideaways under rocks, or in plants near a stream, or in the splashing water from a nearby waterfall. Their call sounds like the repeated ringing of a small, quiet bell. The females arrive, mate with the males, and lay their eggs beneath underwater rocks. In about four or five days, the eggs hatch into tadpoles. The tadpoles turn into froglets when they are 2 years old.

Natal ghost frogs and people: People rarely see this frog.

Conservation status: While the World Conservation Union (IUCN) does not list this rather common frog as being at risk, it does note that the frog's numbers are slowly dropping. It believes several things are to blame. First, loggers and/or farmers are cutting down the forests that are home to this species. The removal of the trees can also muddy up the streams and rivers and make it difficult for the frogs to breed there. This muddying happens because plants, including trees, help keep rain from quickly washing down hills and slopes and taking the soil with it into the water. In addition, people are draining away water from under the ground. People are also putting barriers, or dams, in the rivers. Both activities can cause the levels of the rivers and streams to fall. If too much water disappears, the tadpoles, which need water to survive, could die. Another threat comes from fish, such as trout, that people put in the rivers. People may add trout to a waterway for sport fishing or for food. The problem is that the trout eat many other animals, including tadpoles and frogs. ∎