This Bornean endemic is widely distributed in relatively steep terrain in Sabah and Sarawak, Malaysia, and all provinces in Kalimantan, Indonesia. It is found at elevations from 150–750 m asl.
Habitat and Ecology
Adults disperse widely over the floor and herb stratum of lowland rainforest. It requires small, clear, rocky-bottomed streams to breed in, and larvae live in torrents, clinging to rocks and feeding on lithophytes. It appears to be somewhat adaptable to modified habitats, as it has been recorded from mature oil palm plantations in areas where there are clear streams with good water quality, and some recreational areas (Inger et al. 2017, P. Yambun pers. comm. January 2018).
It appears to be abundant at scattered lowland localities. Due to ongoing decline in the extent and quality of habitat, the population is suspected to be decreasing.
The main threat to the species is deforestation of large portions of the habitat, with the resultant loss of adult and juvenile (through the siltation of streams) feeding microhabitats. Conversion of forest to oil palm plantations is also a threat and it is possible that a broad portion of its range might soon be converted to Acacia plantations. Some of the subpopulations in Sarawak are threatened by logging and conversion of habitat for agriculture, both small and large-scale farming (Y.M. Pui pers. comm. March 2018). In Sabah, the species is adequately protected (P. Yambun pers. comm. January 2018).
In Sabah, it occurs in Kinabalu and Crocker Range National Parks, Danum Valley Conservation Area, and Tawau Hills Park. In Kalimantan, this species has been recorded from Gunung Palung National Park, Raya Pasi Nature Reserve, Bukit Baka Bukit Raya National Park, Gunung Nyiut Nature Reserve, as well as Sebadak Raya Village Forest, which is managed and maintained by indigenous people (Mediyansyah pers. comm. May 2017). It has also been recorded in the conservation area of forest concessions (Kutai Barat District) and oil palm concessions (Penajam Paser Utara District, East Kalimantan Province; Mediyansyah pers. comm. May 2017). In Sarawak, it is thought that more than 50% of the subpopulations occurs in protected areas (Y.M. Pui pers. comm. March 2018).
Sustainable management of conservation areas within the 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. 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 threats.
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 spinulifer. The IUCN Red List of Threatened Species 2018: e.T54483A114916610. http://dx.doi.org/10.2305/IUCN.UK.2018-1.RLTS.T54483A114916610.en .Downloaded on 12 December 2018