This species is thought to be restricted to the Palawan Pleistocene Aggregate Island Complex (PAIC) where it occurs on Palawan, Calauit, Busuanga, Culion, Balabac and Ramos Islands in the Philippines between 0–700 m asl (A. Diesmos pers. comm. March 2018). A subpopulation from Bogani Nani National Park in northern Sulawesi, Indonesia, has also been attributed to this species.
Habitat and Ecology
This species inhabits lowland and lower montane rainforests, as well as secondary growth vegetation and some anthropogenic habitats, such as tree plantations. It breeds in streams by larval development. It is unlikely to tolerate much habitat disturbance and requires forest cover.
In the Philippines, it is common in forested areas and disturbed areas adjacent to forest. In Sulawesi, the species is uncommonly encountered. Due to ongoing decline in the extent and quality of habitat, the population is suspected to be decreasing.
The major threat on Palawan is the destruction and conversion of both lowland and montane rainforest habitat due to small-scale agricultural activities, large-scale oil palm plantations, wood collection for charcoal production, expanding human settlements due to high levels of immigration, nickel and chromite mining, and limestone, sand and gravel quarrying (Philippines Red List Assessment Workshop May 2017). In addition, the quality of its stream habitat is subject to pollution due to agricultural effluents, soil erosion, and mine-tailings (Philippines Red List Assessment Workshop May 2017).
In Bogani Nani National Park, there is encroachment by small-scale agriculture and wood collection.
The range of this species includes several protected areas including Bogani Nani National Park (Sulawesi), Calauit Island Game Preserve and Wildlife Sanctuary (Philippines), and Estrella Falls Protected Landscape (Philippines).
The Strategic Environmental Plan (SEP) for Palawan for areas was put into place by the national government in 1992, which aims to divide the island into a network of environmentally critical areas above 1,000 m asl (ECAN - Environmentally Critical Areas Network). The plan is operationalized on a local level by the Palawan Council for Sustainable Development. The map of these areas is currently being updated to include lowland areas below 1,000 m asl.
The Global Conservation Fund established a $1 million endowment fund for the Mount Mantalingajan range. The funds are held by the Philippine Tropical Forest Conservation Foundation and are used to protect remaining forest on the mountain.
The Philippine Tropical Forest Conservation Foundation is also managing about $30 million in funds from debt payments due to the US government, which are instead allocated for spending during 2016-2026 towards forest protection in three priority areas: Palawan Island, the Sierra Madre on Luzon Island, and eastern Mindanao Island.
Despite being present in several protected areas, the species is still threatened by the continuing decline in the quality and extent of its habitat. Therefore, required conservation measures include the regulation and proper disposal of pesticides and herbicides, and the effective protection of remaining rainforest, especially riverine habitats and gallery forests. In addition, improved enforcement of the SEP is needed as it has had limited success due to challenges in implementation.
Further work is required to clarify the identity of the Sulawesi records.
Red List Status
Least Concern (LC)
Listed as Least Concern due to its wide distribution and presumed large, common, and adaptable population.
The use of the name Sanguirana sanguinea as applied to both Philippine and Sulawesi taxa is a taxonomic arrangement in need of revision. It is expected that Sulawesi subpopulations referred to this species will soon be described as a new species. Song et al. (2002) reported this species for Hainan I., China, but this is likely a misidentification and thus excluded from this assessment.
IUCN SSC Amphibian Specialist Group 2018. Sanguirana sanguinea. The IUCN Red List of Threatened Species 2018: e.T58709A114915766. http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T58709A114915766.en .Downloaded on 20 February 2019