This species is known only from isolated patches in a small area of the mountains of western Cameroon at 950-1,500 m asl: Mount Manengouba, the Bamileke Plateau (at Fotabong, Fontem, and the Mbos Cliffs), Mount Nlonako, and the Rumpi Hills. At Mwakoumel on Mount Manengouba, it co-exists with C. pulchra and C. melanogaster. Using its range as a proxy, the extent of occurrence (EOO) is estimated to be 426 km² based on availability of appropriate habitat. It is unknown whether this species is likely to occur more widely.
Habitat and Ecology
It lives in montane forests and gallery forests near fast-flowing streams in hilly country with high rainfall. It can survive in degraded, secondary habitat provided it is close to more mature forest. It breeds in streams.
The species is largely unknown and there is no quantitative information on its current population status. On Mount Manengouba, it was last seen in 2012, but is very rare there (M. Hirschfeld pers. comm. June 2012). As with other high-elevation amphibians endemic to West and Central Africa, its population is considered to be severely fragmented. The rationale for the severe fragmentation is that the species' dispersal ability is considered to be very limited; its habitat is being gradually fragmented by human activities and these fragments are separated by large extents of unsuitable habitat (further restricting its dispersal ability); and over half the population is estimated to occur in fragmented habitat patches.
The major threat is increasing habitat loss as a result of agricultural encroachment, including plantations of tree crops; expanding human settlements; and removal of wood by local people for firewood and building materials.
On Mount Manengouba, trampling by livestock in the forest is a threat to this species and degrades its habitat; the use of herbicides and pesticides here is suspected to have long-term effects on the stream habitat, affecting the larval stage, and this threat is expected to increase as human activity in the area increases (N. Gonwouo pers. comm. June 2012). Deforestation on Mount Manengouba also occurs due to the unsustainable collection of bark from Prunus africanus—a high-elevation tree endemic to the Cameroon highlands—by the method of tree ringing. The tree's bark is used in small amounts for medicinal purposes by local people. However, it is also sold to pharmaceutical companies in large amounts, in which case all the bark is removed from the individual trees, resulting in their death. The consequence of the latter practice changes the microclimate required for the species' survival (N. Gonwouo pers. comm. May 2012). Furthermore, as with other high-elevation species, the species' habitat may be affected by climate change (N. Gonwouo pers. comm. May 2012), although this necessitates further research.
It may occur in the Rumpi Hills Forest Reserve, but this reserve is not well managed for biodiversity conservation. The protected area network in western Cameroon urgently needs to be expanded to include the remaining montane forest habitats, particularly those on Mount Manengouba, which has been proposed as a protected area (N. Gonwouo pers. comm. May 2012). On Mount Manengouba, the harvesting of Prunus africanus should be sustainably managed, including education of the local people (N. Gonwouo pers. comm. May 2012). More information is needed on this species' distribution, population status, natural history and the potential impact of climate change.
Red List Status
This species is listed as Endangered because its extent of occurrence (EOO) is estimated to be 426 km², its population is considered to be severely fragmented, and the extent of its forest habitat in the highlands of western Cameroon is declining, most of it lacking protection on any level.
IUCN SSC Amphibian Specialist Group, 2015. Cardioglossa venusta. The IUCN Red List of Threatened Species 2015: e.T54411A16866960. http://dx.doi.org/10.2305/IUCN.UK.2015-2.RLTS.T54411A16866960.en .Downloaded on 16 November 2018