This species has been found below 700 m asl in northern and western Borneo, where there are records from Sabah (Malaysia), Sarawak (Malaysia) and Kalimantan (Indonesia). It has also been found at Gunung Penrissen, at 1,000 m asl (Y.M. Pui unpubl. data March 2018).
Habitat and Ecology
This species has been found in primary and slightly disturbed lowland rainforests in flat and hilly terrain, where it perches on low vegetation overhanging small, rocky streams or swampy, muddy pools, in which it is presumed that the larvae also develop.
It can be common in suitable habitat. Due to ongoing decline in the extent and quality of habitat, the population is suspected to be decreasing.
There are no known threats to the species in Sabah, as its habitat is well-protected (P. Yambun pers. comm. January 2018). In Kalimantan, the principal threat to the species is rapid clear-cutting of lowland tropical rainforest in forest concession land and for oil palm plantations (Indonesia Red List Assessment Workshop May 2017). In Sarawak, the lowland forest range of this species outside of protected areas is threatened by logging concessions, small scale subsistence logging and oil palm plantations (I. Das and Y.M. Pui pers. comm. March 2018). Gunung Penrissen has been converted into an 18-hole golf course and a 25 acre area of ‘flower garden and theme parks’), or converted to cultivated land, but there is still some suitable habitat available.
In Malaysian Borneo it has been recorded from a number of isolated protected areas, including Tawau Hills National Park, Danum Valley Conservation Area, Sepilok Orang Utan Conservation Area, and Gunung Mulu National Park. In Kalimantan, this species has been recorded from Bukit Batikap Protected Forest, Murung Raya District, Central Kalimantan Province and Gunung Nyiut Nature Reserve, West Kalimantan Province. Other records occur in conservation areas of forest concessions in Kutai Barat District, East Kalimantan Province. In Sarawak, at least 50% of the population is thought to occur within protected areas (Y.M. Pui pers. comm. March 2018).
Sustainable management of conservation areas within forest and oil palm concessions need to be improved and continued (Mediyansyah pers. comm. May 2017). Effective preservation of lowland forest is needed to conserve this species because oil palm plantations are encroaching into protected areas in Kalimantan. Some oil palm companies and forestry companies designate High Conservation Value areas, which is required by some financial institutions providing loans. However, not all lenders require these areas to be set aside and the habitat within the HCVs could disappear if the lender or requirements change (Indonesia Red List Assessment Workshop May 2017).
Further work is required to improve the understanding of the species' population size, distribution and trends.
Red List Status
Near Threatened (NT)
Listed as Least Concern in view of its wide distribution and presumed large population.
IUCN SSC Amphibian Specialist Group 2018. Feihyla kajau. The IUCN Red List of Threatened Species 2018: e.T58999A114925891. http://dx.doi.org/10.2305/IUCN.UK.2018-1.RLTS.T58999A114925891.en .Downloaded on 20 January 2019