This species is known from the mountains of eastern Nigeria and western Cameroon between 1,000-2,000 m asl. In Nigeria, it has been recorded from the Obudu Plateau. In Cameroon, it is known from Mount Manengouba, the southern fringe of the Bamileke Plateau (at Foto and Mount Bana), Mount Nlonako, the Bamenda Highlands (in the Bafut-Ngemba Forest Reserve), and the Rumpi Hills. At Mwakoumel on Mount Manengouba, it co-exists with Cardioglossa pulchra and Cardioglossa venusta. Its estimated extent of occurrence (EOO) is 16,351 km².
Habitat and Ecology
It lives in montane forest, including dense secondary growth. Males call from shady situations along streams. It is a stream-breeding species. The quality and extent of its habitat is thought to be declining.
It appears to be most abundant between 1,500 and 1,900 m asl, and was last recorded in 2012 (M. Hirschfeld pers. comm. June 2012). As with other high-elevation, forest-dependent amphibians endemic to West and Central Africa, the population of C. melanogaster is considered to be severely fragmented: 100% of the population occurs in isolated and fragmented habitat patches, which is increasingly fragmented by human activities, and these fragments are separated by large extents of unsuitable habitat thereby restricting its dispersal.
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 (M. Hirschfeld pers. comm. June 2012).
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 (Gonwouo pers. comm. May 2012). Furthermore, as with other high-elevation species, the species' habitat may be affected by climate change (Gonwouo pers. comm. May 2012), but this requires further research.
It is found in the Bafut-Ngemba Forest Reserve in Cameroon, which requires continued and improved protection. 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 (N. Gonwouo pers. comm. May 2012). Further research is required on this species' distribution, population status, natural history, and the impact of climate change.
IUCN SSC Amphibian Specialist Group 2015. Cardioglossa melanogaster. In: IUCN 2014