This species is endemic to a portion of montane north-western Sabah, Malaysia in northern Borneo. A large subpopulation occurs in the vicinity of Mesilau in Kinabalu National Park between 1,600 and 2,000 m asl. It is possible that the species occurs more widely within the park, but there are no records yet (P. Yambun pers. comm. January 2018). There are reports of another small subpopulation on Mount Trus Madi at 1,300 m asl, however additional surveys are needed to confirm this. Attempts to locate the species on Gunung Mulu in Sarawak have not been successful.
Habitat and Ecology
Adults disperse widely over the floor of montane and submontane forests. It breeds in small, clear, rocky-bottomed streams and larvae live in torrents, clinging to rocks and feeding on lithophytes. It appears to be unable to adapt to modified habitats.
In the 2004 assessment it was considered to be locally very abundant, particularly in the form of tadpoles. However, in 2015 earthquakes and subsequent landslides completely wiped out the species' habitat at Mesilau, which are thought to have caused significant population declines of at least 80% (P. Yambun pers. comm. January 2018). A short survey was conducted at Mesilau in 2017 by A. Haas, and no individuals were found, however additional surveys are required (P. Yambun pers. comm. January 2018). There is a possibility that this species is extinct.
In 2015, earthquakes caused major landslides at Mesilau, within Kinabalu National Park, where the species was known to occur (Earth Observatory 2017, P. Yambun pers. comm. January 2018). If the species still occurs at Mesilau, the species could be threatened by the development of roads and facilities for tourism within the park (P. Yambun pers. comm. January 2018).
The species occurs in Kinabalu National Park, which is well protected.
There is a particular need to expand the existing protected area network (especially above 1,200 m asl) south of Kinabalu National Park.
Additional surveys are needed to determine whether the species occurs at other sites within Kinabalu National Park.
Red List Status
Listed as Critically Endangered because of population decline, estimated to be more than 80% over the past 10 years, inferred from the complete destruction of its forest habitat at Mesilau on Mt. Kinabulu due to high-magnitude earthquake and subsequent landslides in 2015.
IUCN SSC Amphibian Specialist Group 2018. Ansonia guibei. The IUCN Red List of Threatened Species 2018: e.T54468A123646580. http://dx.doi.org/10.2305/IUCN.UK.2018-1.RLTS.T54468A123646580.en .Downloaded on 21 January 2019