This species is known from three threat-defined locations: Mount Mulanje in southern Malawi and Mounts Namuli and Mabu in northern Mozambique, where it occurs as low as 700 m asl in the Ruo Basin and up to the plateau up to at least 2,500 m asl. As the region is poorly surveyed, it is unknown whether this species could occur more widely (J. Poynton pers. comm. 2012). Records from the Zomba Mountains (north of Mulanje) still need to be confirmed as the region requires extensive surveying. Records from Mounts Namuli and Mabu in northern Mozambique (Broadley 2008, Conradie et al. 2016) may not actually belong to this species, but are retained until formally described as a separate species. The extent of occurrence (EOO) is 7,959 km2, excluding the Zomba records.
Habitat and Ecology
This species inhabits montane evergreen forest, including high-altitude cedar forest. It is most common in the forest, pine plantations and the grassland adjacent to wooded areas. However, open grassland is considered only marginal habitat and, while the pine plantations are utilized as suitable habitat, they are not considered to be of major ecological importance. As the species colonizes pine plantations, it is assumed to be adaptable to only a moderate degree of disturbance, but in general it is believed to favour undisturbed habitats (J. Harvey pers. comm. 2012). It lives in the leaf-litter in areas of very high rainfall. This frog occasionally climbs trees up to at least two metres from the ground. It is presumed to breed by direct development, though the site of egg deposition is not known.
It was recorded as locally abundant in 2005 (Blackburn 2008) and 2009 (Conradie et al. 2011). Due to ongoing decline in the extent and quality of habitat, the population is suspected to be decreasing.
Mount Mulanje is a UNESCO-MAB Biosphere Reserve, but commercial pine plantations have been planted there and small-scale subsistence farming is encroaching on the reserve's protected grasslands and forests. Logging of the pine plantation and illegal logging of native forest by local people is occurring, though does not represent a major threat to this species. The alien invasive Bracken fern (Pteridium aquilinum) poses a threat by suppressing native vegetation and accumulating considerable amounts of dry matter to become a fire risk. The use of fire to manage the grassland, which is a part of the reserve management, is a possible threat to the individuals using edge habitat and the grassland adjacent to the forests. As with other high-altitude species, this species may be vulnerable to Batrachochytrium dendrobatidis infections, as well as to climate change, in as much as the changes would affect average temperature, rainfall, and the extent and viability of its habitat; although the actual effects are unknown.
It occurs in the Mount Mulanje UNESCO Biosphere Reserve. The Mount Mabu forest in Mozambique is under local protection and the core forested area remains intact (Conradie et al. 2016).
Improved protection of the species' habitat and continued management of this area is essential.
Further survey work is required to determine the current population status of this species and more information is needed on the species' taxonomy (in light of the unconfirmed records), natural history and threats (including the potential for chytrid infections and the effects of climate change). Monitoring of the species is required to establish population trends.
Red List Status
Listed as Vulnerable because its extent of occurrence (EOO) is 7,959 km2, it is known from three threat-defined locations, and there is a continuing decline in the number of mature individuals, as well as the extent and quality of its habitat.
IUCN SSC Amphibian Specialist Group & South African Frog Re-assessment Group (SA-FRoG) 2016. Arthroleptis francei. The IUCN Red List of Threatened Species 2016: e.T54371A77165298. http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T54371A77165298.en .Downloaded on 18 November 2018