This species occurs in central and southern Peninsular Malaysia, Singapore, Indonesia (Sumatra, Natuna Besar and Pulau Bintan), and Borneo (Kalimantan, Sabah, and Sarawak). It probably occurs more widely than current records suggest, especially in areas between known sites. It is a lowland species (Malaysia Red List Assessment Workshop January 2018), although the exact elevational range of this species is unknown.
Habitat and Ecology
Swamp forests are the primary habitat for this toad (D. Iskandar pers. comm. May 2017). It is known to breed in standing water. It has been recorded from rubber plantations, presumably close to primary forest (Dring 1979, Chan-ard et al. 1999).
There are no estimates of the size of subpopulations in Borneo; however it appears to be common, but not abundant in intact swamp forests. It is uncommon in Sumatra (Lim and Lim 1992), and it is locally common in Peninsular Malaysia and Singapore (Malaysia Red List Assessment Workshop January 2018). Due to ongoing decline in the extent and quality of habitat, the population is suspected to be decreasing.
The species' habitat is being rapidly reduced due to the expansion of oil palm plantations, infrastructure development and logging. Oil palm and forest concessions are the main causes of deforestation in Kalimantan, where oil palm plantations are encroaching into protected areas (Indonesia Red List Assessment Workshop May 2017).
This species is recorded from a few protected areas in Peninsular Malaysia including the Sungai Dusun Game Reserve, and at least 50% of the subpopulation occurs in protected areas in the country (Malaysia Red List Assessment Workshop January 2018). In Singapore, it is known from the Central Nature Reserves (Baker and Lim 2008). In Sumatra, it occurs in Lembah Harau Nature Reserve and Batang Toru Protected Forest (Indonesia Red List Assessment Workshop May 2017).
Preservation of some areas of swamp forest is needed to save the Bornean subpopulations. 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 information is needed on status of the subpopulations of mainland Southeast Asia.
Red List Status
Least Concern (LC)
Listed as Least Concern in view of its wide distribution, tolerance of a degree of habitat modification, and presumed large population.
Records of Ingerophrynus biporcatus from mainland Southeast Asia probably refer to this species, and are treated as such here.
IUCN SSC Amphibian Specialist Group 2018. Ingerophrynus quadriporcatus. The IUCN Red List of Threatened Species 2018: e.T54741A89871498. http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T54741A89871498.en .Downloaded on 23 January 2019