This species has been found in southern and western Sabah (Malaysia), central Sarawak (Malaysia), and western Kalimantan (Indonesia), on Borneo. It is a lowland species found up to 350 m asl. It is likely to be found more widely.
Habitat and Ecology
This species inhabits primary and old secondary lowland rainforests, where males call from small trees along riverbanks. It has also been found at the forest edge, but it is not likely to tolerate much habitat disturbance (I. Das pers. comm. March 2018). It presumably breeds by direct development, where eggs are laid on leaves.
It can be locally common in some areas. However it can be difficult to observe due to its arboreal nature (I. Das pers. comm. March 2018). Due to ongoing decline in the extent and quality of habitat, the population is suspected to be decreasing.
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, its lowland forest habitat 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). The subpopulation within Gunung Mulu National Park is well protected and not threatened at present (Y.M. Pui and I. Das pers. comm. March 2018).
This species is present in several protected areas, including Crocker Range National Park (Sabah), Long Bisai Indigenous Forest Area, Bukit Baka Bukit Raya National Park, and Gunung Bondang Protected Forest (Kalimantan), and Gunung Mulu National Park (Sarawak).
Effective preservation of lowland forest is needed to conserve this species because oil palm plantations are encroaching into protected areas in Kalimantan (Indonesia Red List Assessment Workshop May 2017). 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 research is needed into the taxonomy, population status and natural history.
Red List Status
Near Threatened (NT)
Listed as Least Concern in view of its wide distribution and presumed large population. However, since this species depends on primary and old growth secondary lowland forest and there is ongoing decline in the extent and quality of these habitats due to widespread forest loss within its range, its population should be monitored.
IUCN SSC Amphibian Specialist Group 2018. Philautus hosii. The IUCN Red List of Threatened Species 2018: e.T58854A114924804. http://dx.doi.org/10.2305/IUCN.UK.2018-1.RLTS.T58854A114924804.en .Downloaded on 15 November 2018