This Bornean endemic is known from throughout Kalimantan (Indonesia), Brunei, and Sabah and Sarawak (Malaysia). It is present in relatively steep terrain from 150–2,200 m asl.
Habitat and Ecology
Adults can be found on the floor and herb stratum of lowland and montane rainforests. It has also been recorded from old secondary forest and selectively logged forest (Inger et al. 2017), provided that clear water is maintained and available (P. Yambun pers. comm. January 2018). It requires small, clear, rocky-bottomed streams to breed in, an environment that persists only where forest cover is intact. Larvae live in torrents, clinging to rocks and feeding on lithophytes.
It is known to be abundant at its known localities. There are some localised habitat loss that may be causing some declines, however the population is considered to be relatively stable (P. Yambun pers. comm. January 2018).
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). The subsequent siltation of streams is an additional threat. In Sarawak, the lowland forest range of this species outside of protected areas is threatened by logging concessions, small scale subsistence logging and agriculture, and oil palm plantations (I. Das and Y.M. Pui pers. comm. March 2018).
This species is known to occur in several protected areas throughout Borneo. In Sabah, it occurs in many well-protected areas, including Kinabalu and Crocker Range National Parks, Danum Valley Conservation Area, Tawau Hills Park, and Imbak Canyon Conservation Area. However, in Kalimantan, some of the existing forest preserves and parks are not well protected as local use of the forests causes degradation.
Effective preservation of lowland forest is needed to conserve this species because oil palm plantations are encroaching into protected areas. 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).
More information is needed on this species' distribution, population status, 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. Ansonia longidigita. The IUCN Red List of Threatened Species 2018: e.T54473A114916400. http://dx.doi.org/10.2305/IUCN.UK.2018-1.RLTS.T54473A114916400.en .Downloaded on 18 November 2018