Family Pyxicephalidae

Cacosternum poyntoni Lambiris, 1988

Poynton’s Caco, Poynton se Caco (A)

By L.R. Minter

Currently accepted name: Cacosternum poyntoni
Red listing status: Data Deficient (2004)

RED LIST SPECIES

Status: Data Deficient (DD)

Identification

The single known specimen, found in a beer bottle at a plant nursery in April 1954, has a body length of 15 mm and differs from other Cacosternum species in its colour and markings: a bold reticulated pattern of dark brown blotches on a yellow background, both dorsally and ventrally (Branch 1988; Lambiris 1988, 1989).

Distribution

This species is known only from the type locality: Town Bush Valley, Pietermaritzburg, KwaZulu-Natal (2930CB).

Habitat

Savanna: Coast–Hinterland Bushveld. Lambiris (1989) described the habitat as “natural woodland with short grass”.

Life History

Nothing is known of the biology of this species.

Conservation

Status

Branch (1988) assigned C. poyntoni to the category “Indeterminate”, i.e. “Taxa that are suspected of being endangered, vulnerable, or rare but for which insufficient information is currently available”.

The species was not assessed during the CAMP workshop (Harrison et al. 2001) because its taxonomic status was regarded, by the majority of participants, as doubtful. Almost 50 years have elapsed since the type specimen was collected, and 15 years since it was formally described. During this time repeated visits to the type locality have failed to produce additional specimens. In addition, the habitat has been invaded by alien plants and is highly degraded.

Although it could be argued that C. poyntoni qualifies for placement in the IUCN “Extinct” category, the strength of this argument is weakened by the fact that it is known from a single specimen, which apparently differs from other similar species only in its colour and markings (characters that exhibit considerable intraspecific variation in amphibians). Since its taxonomic status is in doubt, a cautious approach is taken here in assigning C. poyntoni to the category “Data Deficient” pending the publication of new evidence pertaining to its species status (E. Scott in prep.; see C. n. nanum species account).

The species is not known from any protected area.

Threats

The habitat at the type locality has been degraded and is now totally overgrown by exotic ginger and wattle.

Conservation actions

A further search should be made at the type locality and surrounding area in optimum weather conditions. The result of this survey should be reported in the form of a short note in an appropriate herpetological journal or newsletter. This would assist in bringing closure to this taxonomic problem.

Current distribution map

Undated records;  pre-1996;  1996 to 2002;  2003 to present