Shovel-Nosed Frogs: Hemisotidae

Physical characteristics: The marbled snout-burrower also goes by the common names of marbled shovel-nosed frog, mottled shovelnosed frog, pig-nosed frog, and mottled burrowing frog. The marbled snout-burrower is typically brown with darker brown markings on its back and head and often a light-colored stripe down the middle of the back. Its back toes have a little webbing, but the front toes have none. Its front legs are thick and strong. Females sometimes grow to as much as 2.2 inches (5.5 centimeters) long from snout to rump. Some scientists consider this frog not to be a separate species, but instead to be a subspecies of another species, known as Hemisus marmatorus. Sometimes species are split into one or more subspecies. The marbled snout-burrower also goes by the common names of marbled shovel-nosed frog, mottled shovel-nosed frog, pig-nosed frog, and mottled burrowing frog. (Illustration by Gillian Harris. Reproduced by permission.) This means that the frogs are still members of the same species, but are slightly different. Perhaps they live in separate places or have slightly unusual looks or behaviors.

Geographic range: It lives in much of central and southern Africa.

Habitat: This is a burrowing frog that spends most of the year underground in dry areas, often with few if any trees.

Diet: Marbled snout-burrowers eat a variety of insects above and below the ground.

Behavior and reproduction: Much of the time, marbled snoutburrowers search for and eat various insects that they either find along the ground or in the underground tunnels that they dig. They are especially fond of termites, particularly when the termites develop wings, which they do during part of their life cycle, and leave their termite hills. The frogs wait near the exits to the hills and grab the termites as they fly out.

The frogs mate and have their young next to pools of water or small ponds that remain filled with water all year. Males call and attract females. When a female approaches a male, he grabs hold of her, and she begins digging head first into the soft mud near but outside the pool or pond. When she has dug out a burrow—with the male still clinging to her—she lays her eggs inside the underground nest chamber. The male leaves, but the female stays with her eggs as they hatch into tadpoles underground. When rains come, the pool or pond overflows and soaks the burrow. The tadpoles then swim out. If too little rain falls and the burrow does not flood, scientists think that the tadpoles probably squirm onto the female's back and she carries them out of the burrow and into the nearby pool or pond. In that water body, the tadpoles develop into froglets.

Marbled snout-burrowers and people: People rarely see this mainly underground frog.

Conservation status: The World Conservation Union (IUCN) lists only nine species of shovel-nosed frogs and does not consider this species to be separate from Hemisus marmatorus. According to the IUCN, Hemisus marmatorus is not at particular risk. It lives over a large part of Africa, including protected areas, and is probably quite common. ∎