This species is endemic to the Kenyan Highlands above 1,800 m asl, east of the Rift Valley, on Aberdares Mountains (most commonly collected on the Kinagop Plateau), on Mount Kenya and in the vicinity of Limuru. The records from Nairobi are incorrect and might have been misidentified (P.K. Malonza and V. Wasonga pers. comm. June 2012). The extent of occurrence (EOO) is 16,455 km2 (using range as a proxy for the EOO) within which there are approximately five to six known sites that are thought to represent fewer than 10 threat-defined locations.
Habitat and Ecology
It is a species of montane grassland, moorland and forest patches, and it survives in agricultural land. It breeds by larval development in small, shallow permanent and semi-permanent pools in open areas.
It is a relatively common species in suitable habitat and was recoded during surveys in April 2012. The size of the population is unknown, but it is thought to be decreasing due to ongoing decline in the quality and extent of its habitat.
Although it is somewhat adaptable, it is possibly affected by the intensification of agriculture (mainly potatoes and cabbages), overgrazing by livestock (small scale), and expanding human settlements (P.K. Malonza and V. Wasonga pers. comm. June 2012).
It occurs in Aberdares and Mount Kenya National Parks.
Improved proctection of the species habitat is required.
More work is needed to resolve the taxonomic status of this species and its relatives, in addition to research on its ecology, population size, and distribution.
Red List Status
Listed as Vulnerable because the extent of occurrence (EOO) is approximately 16,455 km2 and it is restricted to fewer than 10 threat-defined locations. Furthermore, there is a continuing decline in the quality and extent of the habitat due to intensive agriculture and human encroachment.
We follow Poynton (1997) in considering Mertensophryne mocquardi and M. nairobiensis as distinct from this species. However, M. Tandy (pers. comm.) considers both M. mocquardi and M. nairobiensis to be synonyms of M. lonnbergi.
IUCN SSC Amphibian Specialist Group 2016. Mertensophryne lonnbergi. The IUCN Red List of Threatened Species 2016: e.T54694A16949350. http://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T54694A16949350.en