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Squeakers and Cricket Frogs: Arthroleptidae

Hairy Frog (trichobatrachus Robustus): Species Accounts



Physical characteristics: The hairy frog is a large, heavy-bodied frog that is most known for the long frills, or "hairs," that grow only on the males and only during the mating season. These frills are actually very thin bits of flesh that develop on the male's thighs and on the sides of the body from his front legs to the rump. Frogs breathe in oxygen with their lungs and through their skin. Actually, it is the blood vessels in the skin that are able to take up the oxygen. Hairy frogs have very small lungs. Scientists believe that the male's frills help them draw in extra oxygen by giving the frogs more skin, and therefore more blood vessels, through which to breathe. This is important for the Scientists believe that the male's frills help them draw in extra oxygen by giving the frogs more skin, and therefore more blood vessels, through which to breathe. (Photograph by R. Wayne Van Devender. Reproduced by permission.) males, which need all the oxygen they can get once they mate and start caring for their young.



Males also have many rough pads on the bottoms of their unwebbed front feet. Their back feet, which are webbed, also have a few pads, but not as many as the front feet have. The pads probably help them hang onto the female during mating. They have very long toes on their back feet. Both males and females are dark greenish brown to black and have a long dark blotch down the center of the back and smaller dark spots toward the rump. In especially dark frogs, the blotch and spots may be difficult to see. Hairy frogs have a yellow throat. Males grow larger than females. Males can reach 5.2 inches (13 centimeters) long, while females reach 3.6 inches (9 centimeters) in length.


Geographic range: Hairy frogs live in the western part of central Africa, including eastern Nigeria, Cameroon, Equatorial Guinea, and parts of the Democratic Republic of the Congo and Gabon. Scientists think it may also live in Angola, although they have not seen any there yet.

Habitat: Hairy frogs especially like to make their homes in areas where thick, lush forests surround fast-flowing streams and rivers. Sometimes, the frogs live on farms, such as tea plantations, but they usually prefer mountain forests. Hairy frogs stay on land nearly all year, but enter the streams and rivers to mate.


Diet: Hairy frogs eat insects and other arthropods that they find along the ground of the forest and the shores of streams.


Behavior and reproduction: Hairy frogs spend most of the year hopping along the forest floor looking for things to eat. When the rainy season comes, their attention turns to mating. Males enter streams and sometimes rivers that have a fast current, but they stay in a quiet spot where the water is very still. After spending a few extra days in the forest, the females join the males in the streams and rivers and mate with them. During mating, the male climbs onto the female's back and holds on near her front legs while she lays her eggs. The pads on his front feet probably help him cling to her body, which is wet and quite slippery.

Each female lays her eggs in the water, and the male stays with them. Water contains oxygen, and the frog's skin, including the frills on his sides and legs, take up this oxygen so the frog can breathe even when he is completely underwater. For this reason, the male can stay beneath the surface with the eggs for days without having to come up for air. The eggs hatch into tadpoles that have a large sucker on the belly side. The sucker helps them attach to rocks and other surfaces in the water. The tadpoles continue to live there, sometimes even venturing into the tumbling foam at the bottom of small waterfalls, before turning into froglets and climbing out onto land.


Hairy frogs and people: Some people collect and eat these large frogs and even the tadpoles. In places where a great deal of hunting takes place, the frogs can become scarce.


Conservation status: Although people do hunt the frogs for their meat, the World COnservation Union (IUCN) does not consider the species to be at risk for now, because the frogs live over a fairly large area, are quite common, and are not hunted everywhere they live. Conservationists are, however, keeping a watchful eye on the frogs. Some streams and rivers where the frogs mate are becoming more polluted, and this may be killing a number of the eggs, tadpoles, and/or frogs. ∎

FOR MORE INFORMATION

Books:

Channing, Alan. Amphibians of Central and Southern Africa. Ithaca, NY: Comstock Publishing Associates, 2001.

Passmore, Neville, and Vincent Carruthers. South African Frogs: A Complete Guide. Revised edition. Halfway House, South Africa: Southern Book Publishers and Johannesburg: Witwatersrand University Press, 1995.

Rödel, Mark-Oliver. Herpetofauna of West Africa. Vol. 1, Amphibians of the West African Savanna. Frankfurt: Chimaira, 2000.

Showler, Dave. Frogs and Toads: A Golden Guide. New York: St. Martin's Press, 2004.


Web sites:

"Breathing." The Frog. http://www.thefrog.org/biology/breathing/breathing.htm (accessed on April 10, 2005).

"Common Squeaker." Herpetology Department, California Academy of Sciences. http://www.calacademy.org/research/herpetology/frogs/list6.html (accessed on April 10, 2005).

"South Malawi Montane Forest-Grassland Mosaic." World Wildlife Fund. http://www.worldwildlife.org/wildworld/profiles/terrestrial/at/at014_full.html (accessed on April 10, 2005).

Additional topics

Animal Life ResourceAmphibiansSqueakers and Cricket Frogs: Arthroleptidae - Physical Characteristics, Habitat, Behavior And Reproduction, Conservation Status, Common Squeaker (arthroleptis Stenodactylus): Species Accounts - GEOGRAPHIC RANGE, DIET, CRICKET FROGS SQUEAKERS AND PEOPLE