This species is endemic to western Cameroon at altitudes of 1,300–2,450 m Asl. The nominate subspecies is recorded from Mount Manengouba, Mount Mbam, Santa, Mount Bana, Mount Ngokham, the Bamboutos Mountains, and the Bafut-Ngemba Forest Reserve, and Mount Oku (Hirschfeld et al. 2016). The subspecies A. r. tchabelensis is known only from the southern slopes of Tchabal Mbaba, at 1,700–1,900 m Asl, in Cameroon, and might occur on the Mambila Plateau in eastern Nigeria. Its EOO is 25,143 km2.
Habitat and Ecology
This species lives in both the submontane and montane zones, and is typically associated with small streams in forest where it breeds. However, at higher altitudes above 2,000 m Asl it can also be found along streams in montane grassland, sometimes bordered with trees. It seems able to tolerate minor disturbance of its habitat. The subspecies A. r. tchabelensis lives in relict gallery forests in a generally deforested area.
It is a very common species. Due to ongoing decline in the extent and quality of habitat, the population is suspected to be decreasing.
Although it is likely that it can tolerate a degree of habitat alteration, this species is probably declining as a result of widespread habitat loss and degradation within its restricted range, mainly due to smallholder agricultural activities, subsistence wood extraction, human settlement and pollution.
A retrospective study analysing amphibian population declines (between 2004–2012) confirms the emergence of Bd in 2008 on Mount Oku and in 2011 on Mount Manengouba, suggesting that chytridiomycosis has driven community level declines of anuran biodiversity in this hotspot area (Hirschfeld et al. 2016). This species tested negative for Bd (Hirschfeld et al. 2016) so its susceptibility to infection remains unknown, however it was still found post Bd emergence on Mount Manengouba and Mount Oku (Hirschfeld et al. 2016). Stresses such as habitat loss are suspected to make amphibian species more susceptible to declines caused by chytridiomycosis, so this species could still be at risk of declines caused by infection (M.-O. Rödel pers. comm. July 2016).
This species occurs in the Bafut-Ngemba Forest Reserve.
More accurate species descriptions are required for the genus to aid identification of specimens (M. Hirschfeld pers. comm. July 2016).
Red List Status
Near Threatened (NT)
Listed as Near Threatened because its extent of occurrence (EOO) is 25,143 km2 and there is decline in the extent and quality of habitat which makes it close to qualifying as Vulnerable under criterion B.
IUCN SSC Amphibian Specialist Group 2017. Astylosternus rheophilus. The IUCN Red List of Threatened Species 2017: e.T54424A95848815. http://dx.doi.org/10.2305/IUCN.UK.2017-2.RLTS.T54424A95848815.en .Downloaded on 16 December 2018