This species is currently known only from two areas: Dida'a, in the Arsi Mountains east of the Rift Valley, and from the Bale Mountains (Böhme and Rödder 2011), in Ethiopia, at 2,000-3,000 m asl. Each area is considered to comprise one threat-defined location. It is likely to occur more widely on the eastern side of the Ethiopian plateau (A. Mengistu and S. Loader pers. comms. June 2012). Its current range, taken as a proxy for extent of occurrence (EOO) is estimated to be 20 km2.
Habitat and Ecology
It occurs in montane grassland and has been found near streams, in cattle grazing fields and in mosaics of cropland, trees, shrubs, grassland and other natural vegetation and in roadside pools in rural towns and villages (Mengistu 2012; A. Mengistu pers. comm. November 2012). Its occurrence in altered habitats suggests that it has a degree of tolerance to habitat disturbance, although probably not to more intense urbanization or to intensification of use of agricultural chemicals in fields (A. Mengistu pers. comm. November 2012). As with other congeners, it is thought to breed by larval development in water.
Surveys conducted in 2010 in both the Arsi and Bale areas suggest that this frog is locally abundant (A. Mengistu pers. comm. June 2012). Its population is not considered to be severely fragmented.
It could be potentially threatened by mechanized agriculture, urbanization and pollution of aquatic habitats by agricultural chemicals (Mengistu 2012).
It is not known from any protected areas. More information is needed on its distribution, natural history and tolerance to threats. The record from south of Ketama, west of the Rift Valley needs to be taxonomically resolved.
Red List Status
Listed as Endangered given that its extent of occurrence (EOO) is estimated at 20 km2, it is known from two threat-define locations (and even if found elsewhere this is liley to be fewer than five locations), and there is a continuing decline in the quality of its habitat in the Arsi and Bale Mountains of Ethiopia.
Böhme and Rödder (2011) recorded Ptychana nana from the type locality, Arussi mountains, ninety years after its description. Furthermore, they discuss the taxonomic relationships of Ptychadena cf. nana from the Bale Mountains. A record referrable to Ptychadena nana was reported and questioned by Largen (2001) from south of Ketama, west of the Rift Valley, but this has yet to be confirmed or validated.
IUCN SSC Amphibian Specialist Group, 2013. Ptychadena nana. The IUCN Red List of Threatened Species 2013: e.T58512A16953411. http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T58512A16953411.en .Downloaded on 16 January 2019