This species occurs in East Usambara and Nguru Mountains in northeastern Tanzania at around 170 to 1,000 m asl, and it is unlikely to be more widespread (S. Loader pers. comm. June 2012). It is estimated to occur in four threat-defined locations (S. Loader pers. comm. June 2012). Taking range as a proxy for extent of occurrence (EOO), this is estimated to be 864 km2.
Habitat and Ecology
It lives in submontane forests, and can survive mild disturbance where good vegetation cover remains, but cannot tolerate complete forest clearance. It lives on the forest floor, where it is semi-fossorial. The eggs are deposited in burrows where they develop directly without a larval stage. A single Probreviceps macrodactylus clutch was found to contain 32 eggs (Müller et al. 2007).
It is a locally common species and its population is not considered to be severely fragmented (S. Loader pers. comm. June 2012).
It is almost certainly being adversely affected by ongoing forest loss, especially for small-scale agriculture. Its habitat in the East Usambaras was historically affected by artisanal gold mining, but this is not likely to have had a major impact on this species (J. Vonesh and S. Loader pers. comm. June 2012) . Some of the major threats to the amphibians of the South Ngurus are forest loss and degradation as a result of fire, selective logging, encroachment from agricultural land and the removal of the forest shrub and herb layer for the cultivation of cardamom and yams (Menegon et al. 2008).
It occurs in the Amani and Nilo Nature Reserves and the proposed Mkingu Nature Reserve, in addition to several forest reserves across the East Usambaras and Ngurus (S. Loader pers. comm. June 2012). These reserves are relatively well protected in comparison to other protected areas in the region, but there is still a need for increased protection and improved management (S. Loader pers. comm. June 2012). More information is needed on this species' distribution, population status and natural history, as well as clarification of its taxonomic identity.
Red List Status
Listed as Endangered because its extent of occurrence (EOO) is estimated to be 864 km2, it is considered to occur in four threat-defined locations, and there is continuing decline in the extent and quality of its forest habitat in the Eastern Arc Mountains of Tanzania.
We follow Poynton (2003b) and Channing and Howell (2006) in considering Probreviceps rungwensis to be distinct from P. macrodactylus. In addition, we follow Mkonyi et al. (2004) and Channing and Howell (2006) in considering Probreviceps loveridgei to be distinct from P. macrodactylus. Furthermore, molecular data suggest that there are more than one species under the P. macrodactylus name (S. Loader pers. comm. June 2012).
IUCN SSC Amphibian Specialist Group 2013. Probreviceps macrodactylus. The IUCN Red List of Threatened Species 2013: e.T57980A3063584. http://dx.doi.org/10.2305/IUCN.UK.2013-2.RLTS.T57980A3063584.en .Downloaded on 21 January 2019