This species is known from the lower slopes of Mount Cameroon at 700-1,200 m asl, from Mount Kupe around 900 m asl. The taxonomic status of the highly disjunct population from the highlands of west-central Togo ("Bismarkberg") is unclear, and there have been no records from Togo for more than 100 years. It possibly has a wider range across the Cameroonian highlands than is currently known.
Habitat and Ecology
It is associated with rocky streams and waterfalls in submontane forest and degraded secondary habitats. The lack of permanent streams at high elevations on Mount Cameroon probably imposes an altitudinal limit on the species in this part of its range, since it breeds in streams and lives exclusively in and around water.
It is common, perhaps even abundant, in suitable habitat on Mount Cameroon. A survey in eastern Ghana in 2001 very close to the Togo highlands failed to recover this species.
It is presumably at risk from forest loss due to agricultural encroachment and human settlement.
It does not occur in any protected areas, and protection of remaining forest habitat on Mount Cameroon and Mount Kupe is urgently needed. An ecotourism project has been established at Mount Kupe for some time, which aims to reduce hunting and agricultural expansion, and the area has been proposed as a Strict Nature Reserve (Réserve Écologique Intégrale). Further survey work is needed to confirm the existence and status of the population in Togo.
Studies are needed to determine whether or not specimens from Cameroon and Togo belong to the same species (M.-O. Rödel pers. comm.). It is currently unclear whether there are any Werneria species in Togo, but it has been suggested that if there is one, it could be either W. preussi or alternatively a different, distinct species, Werneria africanus, which would be an endemic species to Togo (see Segniagbeto et al. 2007).
Amiet, J.-L. & Rödel, M.-O. 2009. Werneria preussi. In: IUCN 2014