This species is known from three closely adjoining localities in the foothills of the East Usambara Mountains in northeastern Tanzania. All records (Kwamgumi FR, Mtai FR, and Segoma FR) have been from below 410m asl. Its extent of occurrence (EOO) is 43 km2.
Habitat and Ecology
It is a terrestrial species of lowland forest, but also has been recorded in mildly disturbed, selectively logged forest areas. Its breeding behaviour is unknown, but it might breed in puddles in tree roots like some congeners.
It appears relatively uncommon within its very small known range given the scarcity of individuals collected and survey effort: broad scale biodiversity surveys in East Usambaras found few individuals (12 in total) (Poynton and Clarke, 1998) and a survey in 2012 found 2 individuals from 3 days of intensive survey effort (S. Loader pers. comm. December 2015). Due to ongoing decline in the quality and extent of its habitat, its population is suspected to be decreasing.
There is ongoing loss of its habitat due to agricultural encroachment, wood extraction, and human settlement.
It occurs in the Kwamgumi, Segoma and Mtai Forest Reserves.
The forest reserves in which it occurs are not well protected and are in need of improved management.
Further information is required on the species distribution, population status and breeding strategy.
Red List Status
Critically Endangered (CR)
Listed as Critically Endangered because its extent of occurrence (EOO) is 43 km2, all individuals occur in one threat-defined location, and there is continuing decline in the extent and quality of its habitat.
IUCN SSC Amphibian Specialist Group 2016. Mertensophryne usambarae. The IUCN Red List of Threatened Species 2016: e.T54890A84397352. http://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T54890A84397352.en .Downloaded on 18 January 2019