This species is endemic to the high slopes of the Drakensberg Mountains and Lesotho Highlands, in South Africa and Lesotho. It occurs between 1,800-3,000 m asl, with an extent of occurrence of 4,673 km2 and an area of occupancy of 88 km2. There are four threat-defined locations.
Habitat and Ecology
It lives in high-altitude riverine grassland. It breeds in seepage areas on the rocky banks of slow-flowing streams, or near the edges of pools. It lays its eggs in water. Tadpoles have been observed swimming under ice. Adults have been observed sitting basking on rocks. Breeding takes place throughout the year.
This species is relatively easy to find in its upland locations, and is locally abundant where it occurs. Large die-offs of both adults, juveniles and tadpoles have been observed over the past decade, especially around Mont-aux-Sources (J. Tarrant pers. comm. August 2016). There are several undocumented chytrid related die-off events recorded for this species at several sites (L. du Preez and C. Weldon pers. comm. December 2009), and chytrid infection rate is up to 38.6% in tadpoles (Smith et al. 2007), although these subpopulations at these same sites still appear healthy (L. du Preez and C. Weldon pers. comm. December 2009).
Large numbers of adults and juveniles die every year from chytrid infections (Meyer 2009). In addition, large tadpole die-offs from drying of streams and severe freezing in winter. Additional threats may include trampling and grazing. Greatest observed threat from climate change with extreme drying and chytrid acting on a limited number of locations.
Its range includes uKhahlamba-Drakensburg Park.
Studies on its population size, distribution and trends, life history and ecology, and threats are needed. In particular, the stability of the adult population should be assessed and chytridiomycosis impacts monitored.
Red List Status
Near Threatened (NT)
Listed as Near Threatened because the small EOO (4,673 km2) and AOO (88 km2) would qualify this species as Endangered were any threats to its habitat confirmed.
Until 2008 the Maluti River Frog was referred to Amietia vertebralis and the Phofung River Frog to Strongylopus hymenopus; a recent revision of type specimens has clarified the confusion between the two species, showing that Amietia vertebralis is widespread in Lesotho, KwaZulu-Natal and the Eastern Cape Province in South Africa, while Amietia hymenopus occurs within a more restricted range range in north-eastern Lesotho and the Drakensberg highlands (Channing 2015).
IUCN SSC Amphibian Specialist Group & South African Frog Re-assessment Group (SA-FRoG) 2016. Amietia hymenopus. The IUCN Red List of Threatened Species 2016: e.T58768A77166198. http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T58768A77166198.en .Downloaded on 18 January 2019