This species appears to be endemic to the Kenyan Highlands above 1,800m asl, where it occurs on both sides of the Rift Valley, and on Mount Kenya and in the vicinity of Limuru. Records from Nairobi require confirmation. A related species has been found in the Udzungwa Mountains of southern Tanzania, but this has not so far been named.
Habitat and Ecology
It is a species of montane grassland, moorland and forest patches, and it survives in agricultural land. It breeds in small, shallow permanent and semi-permanent pools in open areas.
It is a reasonably common species. There is some evidence of a decline at one site, but there is no information as to whether or not such a decline might have been more widespread (M. Tandy pers. comm.).
There is little information on its threats, but although it is somewhat adaptable, it is possibly affected by the intensification of agriculture, overgrazing by livestock, and expanding human settlements.
It occurs in Aberdares and Mount Kenya National Parks. More work is needed to resolve the taxonomic status of this species and its relatives.
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.
Mills Tandy, Stefan Lötters, John Poynton, Kim Howell 2004. Mertensophryne lonnbergi. In: IUCN 2014