Cover photo by Trevor Hardaker.
Find the Mountain Caco in the FBIS database (Freshwater Biodiversity Information System) here.
Family Pyxicephalidae
Habitat
The Mountain Caco is restricted to high altitudes above 1200 m where it breeds in ponds, marshes, streams, and flooded grassland.
This species vies with C. striatum for the title of the smallest frog in South Africa. Its small size reflects a marked trend in the genus towards size reduction in high-altitude forms.
Behaviour
Very little is known of the life history of the Mountain Caco. Specimens recorded near Graskop, Mpumalanga Province, were calling from beneath grass at the edge of shallow puddles in inundated grassland, while another population was breeding at a seep on a grassy slope. Advertisement and (presumably) agonistic calls were recorded (L.R. Minter pers. comm.).
Status and Conservation
The Mountain Caco has been recorded from the Royal Natal National Park and the Giants Castle and Cathedral Peak nature reserves in KwaZulu-Natal Province, as well as Malolotja Nature Reserve in Swaziland. The species is locally abundant, and is not threatened or in immediate need of conservation action.
Distribution
There has been much confusion in the literature surrounding the separation and distribution of C. nanum and C. parvum, because the key in Poynton (1964) provides inadequate characters to separate these species. Poynton (1964) and Lambiris (1989a) listed grid localities where both species are supposedly present, but these were based on some specimens being identified as both nanum and parvum (Bates 1995). Material examined from all of these contested localities was found to be referable to C. parvum (E. Scott in prep.), and no specimens of C. nanum have been obtained from any of these localities.
C. parvum occurs in high-altitude habitats above 1200 m along the Drakensberg escarpment. It is known from the northern parts of Eastern Cape Province but appears to have its stronghold in KwaZulu-Natal, with an apparent gap between populations in this province and those farther north, in Swaziland and Mpumalanga Province. The identity of the isolated specimen from near Louis Trichardt (2330AB), mentioned by Poynton (1964), has not been confirmed.
C. parvum has been recorded in sympatry with C. nanum at Malolotja Nature Reserve (2631AA) in Swaziland (R.C. Boycott pers. comm.), and in the Maclear (3128AB) and Mount Frere (3028DD) districts in the Eastern Cape Province (M. Burger pers. comm.).
The advertisement calls of C. nanum and C. parvum are sufficiently different to allow recognition in the field and were used to identify populations during the atlas period. The distribution map for C. parvum presented here is based mainly on aural records. The atlas data are accurate but incomplete.
Further Resources
The use of photographs by Trevor Hardaker is acknowledged.
Mountain Caco Cacosternum parvum Poynton, 1963
Other Common Names: Mountain Dainty Frog (Alternative English Names); Berg Blikslanertjie (Afrikaans)
Recommended citation format: Scott, E; Tippett, RM. (2025). Mountain Caco Cacosternum parvum. Biodiversity and Development Institute, Cape Town. Available online at https://thebdi.org/2022/02/17/mountain-caco-cacosternum-parvum/
This species text has been updated and expanded from the text in the
2004 frog atlas: Scott, E. (2004). Mountain Caco Cacosternum parvum In Minter LR et al 2004.
References:
Minter, LR; Burger, M; Harrison, JA; Braack, HH; Bishop, PJ; Kloepfer, D. (Editors). (2004). Atlas and Red Data Book of the Frogs of South Africa, Lesotho and Swaziland. Smithsonian Institution, Washington, and Avian Demography
Unit, Cape Town.
Carruthers, V; du Preez, L. (2017). Frogs of southern Africa: A Complete Guide. Struik Nature, Cape Town.
Channing, A. (2001) Amphibians of Central and Southern Africa. Protea Book House, Pretoria
