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This species occurs on the islands of Busuanga, Culion, and Palawan, all in the western Philippines. It probably occurs more widely than current records suggest, especially in areas between known sites on Palawan. It is a lowland species occurring up to 300m asl, perhaps up to 500m asl.

This aquatic species inhabits clear, unpolluted swift-flowing mountain streams and rivers in lowland rainforests, where it usually floats near the surface of the water unless disturbed, when it will hide under submerged rocks. The breeding strategy of this species remains unknown. Tadpoles have never been observed, and eggs collected from gravid females were large, unpigmented, and few in number (Inger 1954), suggesting that it could possibly reproduce by direct development (Brown and Alcala 1983). However to date breeding habits have not yet been observed. It has not been found in open habitats outside forest.

It commonly occurs in large numbers where known, though the overall distribution is patchy and fragmented.

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The lowland rainforest habitat of this species is generally protected on the island of Palawan. However, some populations are threatened by habitat conversion, shifting agriculture, quarrying, large-scale mining, and pollution of streams and rivers from agricultural effluents. The collection of frogs for the pet trade (including internationally) is also a possible threat.

• 2.1.1 Shifting agriculture
• 9.3.4 Type Unknown/Unrecorded
• 3.2 Mining & quarrying
• 9.3.2 Soil erosion, sedimentation
• 5.3.5 Motivation Unknown/Unrecorded

There is a need for remaining intact lowland rainforest of Palawan to be designated as protected areas. Further research is needed to establish the levels of offtake of this species from the wild for the international pet trade; if proved to be a significant threat, then this species could also warrant listing by CITES.

• 2.1 Site/area management
• 4.2 Training
• 1.1 Site/area protection
• 2.3 Habitat & natural process restoration
• 5.1.2 National level
• 4.3 Awareness & communications
• 5.4.2 National level

Listed as Vulnerable because its Extent of Occurrence is less than 20,000 km2, its distribution is severely fragmented, and there is continuing decline in the extent and quality of its forest habitat.

• Alcala, A.C. and Brown, W.C. 1985. Philippine Amphibians: An Illustrated Field Guide. Bookmark Press, Makati City, Philippines.
• Brown, R.M., Diesmos, A.C. and Alcala, A.C. 2001. The state of Philippine herpetology and the challenges for the next decade. Silliman Journal 42(1): 18-87.
• Brown, W.C. and Alcala, A.C. 1983. Modes of reproduction of Philippine amphibians. In: Rhodin, A.G.J. and Miyata, K. (eds), Advances in Herpetology and Evolutionary Biology: Essays in Honors of Ernest E. Williams, Museum of Comparative Zoology, Cambridge, Massachusetts.
• Frost, D.R. 1985. Amphibian Species of the World: A Taxonomic and Geographic Reference. Allen Press and the Association of Systematic Collections, Lawrence, Kansas.
• Infante, C.R., Brown, R.M., Diesmos, A.C., Gee, G. and Dimalibot, J. 2002. The Search for the Lost Treasure of Palawan: the Philippine Flat-headed Frog. Haring Ibon: 12-15.
• Inger, R.F. 1954. The systematics and zoogeography of Philippine Amphibia. Fieldiana 33: 181-531.
• Inger, R.F. 1999. Distributions of amphibians in southern Asia and adjacent islands. In: W.E. Duellman (ed.), Patterns of Distribution of Amphibians: A Global Perspective, pp. 445-482. John Hopkins University Press.
• Myers, G.S. 1943. Rediscovery of the Philippine discoglossid frog, Barbourula busuangensis. Copeia: 148-150.
• Taylor, E.H. and Noble, G.K. 1924. A new genus of Discoglossid frogs from the Philippine Islands. American Museum Novitates: 1-4.