This species is endemic to the mountains of western Cameroon at 1,900-2,650 m asl in the Bamboutos Mountains of the Bamenda Highlands, the Bafut-Ngemba Forest Reserve, and Mount Oku. Individuals recorded on Mount Manengouba were in fact Cardioglossa manengouba (N. Gonwouo pers comm. May 2012; Blackburn 2008). Using its range as a proxy, the extent of occurrence (EOO) is estimated to be 1,383 km²
Habitat and Ecology
The species lives in montane forest, often in bamboo forest, and in degraded habitats containing trees. It is associated with areas around fast-flowing streams, where they sit on leaves, or hide in holes and under stones, and breed in streams.
It is believed to be common within its small range. However, as with other high-elevation amphibians endemic to West and Central Africa, its population is considered to be severely fragmented because its dispersal ability is very limited; its habitat is increasingly fragmented by human activities and these fragments are separated by large extents of unsuitable habitat thereby further restricting its dispersal ability; and the majority of the population is known only from fragmented habitat patches.
Major ongoing threats to this species are advanced deforestation; encroaching human settlements; agricultural expansion, which expands onto higher elevations on Mount Bamboutos; overgrazing and cattle trampling the forest to drink from streams; and the degradation of the species' aquatic habitat caused by the use of agricultural herbicides and pesticides (N. Gonwouo pers. comm. May 2012). As it is a high-elevation species, agricultural activities may push it to the extreme part of its elevational range and it may be susceptible to microhabitat changes caused by climate change including alteration of temperature and moisture gradients, and rainfall patterns. However, this necessitates further research.
The species occurs in the Bafut-Ngemba Forest Reserve, but is largely unprotected elsewhere in its range. A conservation project was conducted on Mount Oku for several years by BirdLife International, involving community management of the area by the local villages. However, this project ended in the mid-2000s.
IUCN SSC Amphibian Specialist Group, 2015. Cardioglossa oreas. In: IUCN 2014