Amietophrynus superciliaris

African Giant Toad (Sclerophrys superciliaris)

The African giant toad, also referred to as the Congo toad or Cameroon toad, is a significant amphibian species belonging to the Bufonidae family. It is native to the tropical regions of Central and West Africa, with its distribution spanning countries like Cameroon, Nigeria, Ghana, and the Democratic Republic of the Congo, and possible presence in Liberia and Sierra Leone. This species thrives in subtropical or tropical moist lowland forests, freshwater marshes, and even heavily degraded former forest areas, often found in dense undergrowth and plantations.

Description and Identification

A visually distinctive amphibian, the African giant toad possesses a robust, broad ovoid body and a short snout. Its head features nearly-vertical sides and an unridged crown, with closely set eyes. A notable characteristic is the pointed projection extending from the upper eyelid. While the tympanum is indistinct, the parotid glands are large. The first finger of the hand is longer than the second, and males develop nuptial pads on their first two fingers. The hind limb toes are short and partially webbed. The skin on its back can be either smooth or bear small warts. Its coloration provides excellent camouflage, mimicking a dead leaf. The upper surfaces are typically pale brown, yellowish, or pinkish, with a distinctive backward-pointing V-shaped black mark between the eyes and sometimes dark spots on the back. A thin, pale stripe may run along the spine. The sides of the head and body are considerably darker than the upper parts, and the underparts are grey speckled with white. A thin white line borders the lower jaw. The limbs are marked with dark bands, and the back of the thigh, alongside occasional flanks, are a striking bright red.

Taxonomy and Subspecies

The African giant toad is considered a species complex, with distinct populations across its range. There have been proposals to divide the species into three taxa: two subspecies, S. superciliaris superciliaris (found in western Lower Guinean forests) and S. superciliaris chevalieri (found in Upper Guinean forests), and a new species, Sclerophrys channingi, identified in the eastern Democratic Republic of Congo. Genetic analysis supports these distinctions, with S. channingi differing genetically and morphologically, including less-pointed eyelid processes and a darker posterior abdomen.

Size and Reproduction

This is a large toad species. The subspecies A. s. chevalieri is the largest, with adult males averaging 127 mm (5.0 in) in snout-to-vent length, while A. s. superciliaris averages 112 mm (4.8 in). The newly described species, A. channingi, is smaller, averaging 109 mm (4.3 in). Females are generally larger than males. Breeding is thought to occur during the dry season, from January to March. Eggs are laid in streams in calm water, likely as long strings wrapped around submerged vegetation.

Diet and Behavior

Little is known about the specific biology of the African giant toad. Its diet is presumed to consist of invertebrates found in its environment, such as ants, which are a confirmed food source. In captivity, it has also consumed snails, insects, other frogs, and tadpoles. The species is nocturnal and its cryptic coloration makes it difficult to spot, leading to speculation that it may be more common than currently believed.

Conservation

Despite its wide distribution and presumed large population, which has led to its 'least concern' classification by the IUCN, the African giant toad faces threats, primarily from habitat loss due to logging activities. This is particularly critical in West Africa, where the species is restricted to primary forests. While it appears more adaptable in other regions, the loss of dense tree cover remains a concern. Historically, it was collected for the pet trade, and although this is now illegal, it may still occur occasionally.