This species is currently known only from approximately 1,300–2,000 m asl in Lam Dong, Dak Lak and Khanh Hoa Provinces in the Central Highlands of Viet Nam (Orlov et al. 2008, Le 2011, Orlov et al. 2012, J. Rowley unpubl. data). This may not represent the actual limits of the species' range as similar habitat and elevations to those in its known localities extend into adjacent western Ninh Thuan Province. Further surveys may uncover its presence there, therefore its range has been projected beyond known sites to include these areas of suitable habitat. This species' extent of occurrence (EOO) is 4,138 km2, which consists of five threat-defined locations.
Habitat and Ecology
This species is associated with evergreen forest and has mostly been observed in trees or other vegetation above the ground adjacent to streams including cascades (Orlov et al. 2008, Le 2011, J. Rowley unpubl. data). The species breeds mostly in streams; amplexus occurs on the leaves and branches of trees adjacent to streams (Le 2011). Calling males, amplexus, tadpoles and metamorphs have been observed in March and May (J. Rowley unpubl. data). Most observations of this species' tadpoles have been in pools within streams (J. Rowley unpubl. data).
Little is known about the size and trends of this species' population except that it has been detected in relatively few surveys (Orlov et al. 2008, Le 2011, Orlov et al. 2012, J. Rowley unpubl. data). It has been described as the most abundant frog during the wet season at a survey site in Bidoup-Nui Ba National Park (Le 2011), and relatively abundant during the breeding season (J. Rowley pers. comm. December 2015). Deforestation continues to affect habitat in the species' range (Meyfroidt and Lambin 2008, Sodhi et al. 2009, Meyfroidt et al. 2013), and is very likely causing declines. Surveys are needed to determine its relative abundance and population trends.
This species is likely threatened by collection from the wild to meet high demand from the international pet trade, as is the case for similarly attractive frog species from the region (Rowley et al. 2010). Habitat loss and degradation due to rapidly expanding agriculture is an ongoing threat to biodiversity throughout Viet Nam (Sodhi et al. 2009). In the Central Highlands, large areas of forest are converted to agricultural land to grow cash crop plantations (e.g. rubber, coffee and tea) (Meyfroidt and Lambin 2008, Meyfroidt et al. 2013). The species is also very likely threatened to some degree by habitat loss.
This species is known from Chu Yang Sin and Bidoup-Nui Ba National Parks (Orlov et al. 2008, Orlov et al. 2012). Phuoc Binh Proposed Nature Reserve is included in parts of this species' predicted range; it may occur there also.
Increased protection of evergreen forests where this species occurs may be needed to mitigate further declines. Effective trade management should also be implemented to ensure the species is not harvested from the wild.
In order to ensure the species' long-term survival, the lack of data must be addressed; research should be carried out to determine its true distribution, relative abundance, rates of harvest, and threats.
Red List Status
Near Threatened (NT)
Listed as Endangered as this species has an extent of occurrence (EOO) of 4,138 km2, is expected from five threat-defined locations, and is facing a continuing decline in the quality of parts of its habitat.
In the Rhacophorus calcaneus group of Orlov et al. (2012), who noted extensive confusion with Rhacophorus robertingeri in the literature and who discussed previous confusion in the range.
IUCN SSC Amphibian Specialist Group 2018. Rhacophorus calcaneus. The IUCN Red List of Threatened Species 2018: e.T48103132A87891016. http://dx.doi.org/10.2305/IUCN.UK.2018-1.RLTS.T48103132A87891016.en .Downloaded on 23 January 2019