This species occurs in montane forests in central Viet Nam (Thua Thien-Hue, Da Nang, Quang Nam, Kon Tum and Gia Lai Provinces) at relatively high elevations, between 1,100-1,905 m asl (Orlov et al. 2004, Rowley et al. 2011, J. Rowley pers. comm. 2015). The type locality is Bach Ma National Park, Viet Nam (Orlov et al. 2004). It also occurs in the provinces of Salavan and Khammouane in southern Lao PDR (Luu et al. 2014). Because suitable habitat is widely available, its range has been projected beyond known sites to include these areas of suitable habitat. These areas were excluded from the estimate of extent of occurrence (EOO) resulting in a value of 21,941 km2, within which its area of occupancy (AOO) is estimated to be 2,977 km2.
Habitat and Ecology
It occurs in high elevation montane evergreen forests where it has been observed on leaves and branches of low-lying vegetation above shallow, non-flowing water bodies (Orlov et al. 2004, Rowley et al. 2011, Luu et al. 2014, J. Rowley pers. comm. 2015). This usually includes shallow pools and puddles that are near streams (Orlov et al. 2004, Rowley et al. 2011, Luu et al. 2014, J. Rowley pers. comm. 2015), although the species has also been observed in large numbers on emergent vegetation in a large swamp (J. Rowley pers. comm. 2015).
Females are known to deposit clutches of 5-8 eggs on top of leaf surfaces near the tip, with each clutch appearing like a clump of clear jelly (Orlov et al. 2004, J. Rowley pers. comm. 2015). Orlov et al. (2004) reported the presence of an attendant male guarding a clutch. While larvae have been observed at various developmental stages (Orlov et al. 2004), the reproductive and breeding biology of the species remain poorly known (J. Rowley pers. comm. 2015).
The abundance and population trends of this species are unknown. However, it is not thought to be severely fragmented and, due to ongoing habitat loss, its population is suspected to be decreasing.
Due to human population growth and increasing demand for agricultural and timber products as well as road construction, the loss of montane forest habitat is ongoing and expected to increase throughout central Viet Nam (Meyfroidt et al. 2013, Truong Nguyen pers. comm. 2015). Thus, habitat loss due to expanding human settlements, shifting and small-scale agriculture, logging and roads is a threat to this forest-dependent species.
It occurs in a number of protected areas in Viet Nam, including Bach Ma National Park, Ba Na National Park (Orlov et al. 2004), Kon Ka Kinh National Park, and Ngoc Linh Nature Reserve (J. Rowley pers. comm. 2015). In Lao PDR, the species is found in Xe Xap National Biodiversity Conservation Area and Hin Nam No National Biodiversity Conservation Area (Luu et al. 2014). Nonetheless, parts of the species’ range lie outside protected areas and are susceptible to habitat loss.
Improved protection of forest habitat throughout the species range is required.
Further biological and ecological research of the species is needed for a better understanding of its distribution and abundance, which would assist future conservation actions.
Red List Status
Near Threatened (NT)
Listed as Near Threatened since the species has an area of occupancy (AOO) of 2,977 km2, an extent of occurrence (EOO) of 21,941 km2, and there is ongoing degradation and loss of its habitat, which may be causing the population to decrease. It is thus close to qualifying as Vulnerable B1ab(iii)+B2ab(iii).
IUCN SSC Amphibian Specialist Group 2016. Gracixalus supercornutus. The IUCN Red List of Threatened Species 2016: e.T61890A47152824. http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T61890A47152824.en .Downloaded on 15 December 2018