Cacosternum thorini
Hogsback Dainty Frog
family: Pyxicephalidae
subfamily: Cacosterninae
Species Description: Conradie W 2014 The king of dwarves: a new cryptic species of Dainty Frog (Anura: Pyxicephalidae: Cacosternum) from the eastern GReat Escarpment of South Africa. Zootaxa 3785: 438-452.
Conservation Status (definitions)
IUCN (Red List) Status Endangered (EN)
Other International Status None
National Status None
Regional Status None

Country distribution from AmphibiaWeb's database: South Africa



View distribution map using BerkeleyMapper.

From the IUCN Red List Species Account:


Range Description

This species is known only from two threat-defined locations in the Amathole Mountains: near Hogsback and eastwards to Thomas River in the Eastern Cape Province of South Africa (Conradie 2014). It occurs in montane wetlands between 1,200 and 1,500 m Asl (Conradie 2014). Its EOO is 166 km2 and within that, its AOO is estimated to be 14 km2.

Habitat and Ecology

It inhabits wetlands in montane grassland. Each female lays about 40 eggs in separate pools. Males are territorial and occupy a single pool in main wetland.


It can be common in suitable permanent montane wetlands. However, its population is considered severely fragmented because the habitat between known sites of occurrence has been channalised and drained, therefore it is not suitable anymore. Recent surveys of all the wetlands in the Amathole Forestry Company area confirm the species to be present in nine out of 20 surveyed (W. Conradie pers. obs. October 2014).

Population Trend


Major Threats

The main threats are the drying out of wetlands due to their channelisation, increase of invasive plants, cattle farming, uncontrolled fires and small scale agriculture.

Conservation Actions

Conservation Actions
It is not known from any protected area. The Amathole Forestry Company is aware of this species and its limited range, and is managing the burning of the wetlands (W. Conradie pers. comm. August 2016). 

Conservation Needed
The habitat of this species would need to be protected and managed.

Research Needed
Studies on its population size, distribution and trends, life history and ecology, and threats are needed. It should be looked for in the Winterberg and montane wetlands further north to the Stormsberg area.

Red List Status

Endangered (EN)


It is listed as Endangered because both area of occupancy (AOO) and extent of occurrence (EOO) are very small (14 km2 and 166 km2, respectively), its population is considered severely fragmented with all individuals occurring in two locations, and there is continuing decline in the extent of its habitat in the permanent montane wetlands of the Eastern Cape Province in South Africa.


IUCN SSC Amphibian Specialist Group, South African Frog Re-assessment Group (SA-FRoG) 2017. Cacosternum thorini. The IUCN Red List of Threatened Species 2017: e.T76317542A76317884. .Downloaded on 24 February 2019


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