Palawan horned frog  (Megophrys ligayae)

Classified as Endangered (EN) on the IUCN Red List (1).

Named for the elongated, triangular ‘horn’ on each upper eyelid, the Palawan horned frog, like other members of the genus, is a superbly camouflaged amphibian, its light brown to grey body, with one or two pairs of ridges running down the back, showing a remarkable resemblance to a dead leaf. The head is quite large and wide, the snout is pointed, and there is a dark triangular blotch behind the eyes, which are dark brown, with vertical pupils (2) (3). A fold of skin separates the head from the body (2). As in other Megophryidae species, the long digits of the forefeet are unwebbed, while those of the hindfeet show some webbing (3), and the legs are relatively short and slender in comparison to the body (2). Although previously classified together with the Javan horned frog, Megophrys montana, the Palawan horned frog is now recognised as a separate species (1) (4).

The Palawan horned frog, as its name suggests, occurs on the island of Palawan, as well as on nearby Balabac, in the western Philippines (1) (2) (4). It appears to have a patchy distribution, although the species may be more widespread than is currently believed (1).

This species inhabits leaf litter on the floor of lowland and montane rainforest, and is usually found near the mountain streams in which it breeds (1) (2) (3).

The Palawan horned frog is reported to be active both day and night, moving along the ground in short hops rather than jumps, and relying on camouflage for defence (2). Little information is available on the biology of this species, but, like its close relatives, it is likely to feed on a range of invertebrate prey, and possibly also on smaller frogs. The males of some horned frog species call from shallow streams during heavy rain, producing a loud and mechanical-sounding ‘clank’ (3). The Palawan horned frog lays its eggs in mountains streams, where the tadpoles prefer quiet pools and are suspension feeders, filtering small food particles from the water (1) (2). However, little else is known about the life cycle of this species.

The main threat to the Palawan horned frog is the loss of lowland rainforest habitat to agriculture, while the pollution of mountain streams and rivers, from agricultural run-off and mining, is also negatively impacting the species (1) (2). The area occupied by the Palawan horned frog is now small and severely fragmented, which, together with the continued decline in the extent and quality of its habitat, puts it at particular risk of extinction (1). Many amphibian species are coming under increasing pressure from factors including climate change and disease (5), but it is not known to what extent these are currently affecting the Palawan horned frog.

The Palawan horned frog is found in several protected areas, although water pollution may still impact the species within these. Specific conservation measures recommended for this endemic amphibian include the regulation and proper disposal of agricultural chemicals, and the effective protection of the remaining rainforest, particularly that occurring along streams and rivers (1) (2). General conservation actions suggested for other amphibians, such as captive breeding, disease research and increasing public awareness (5), may also potentially benefit the Palawan horned frog, as may further research, surveys and population monitoring (2).

View information on this species at the UNEP World Conservation Monitoring Centre.

To find out more about the conservation of this and other amphibians, see:

• Amphibia Web:
  http://www.amphibiaweb.org/
• IUCN / SSC Amphibian Specialist Group:
  http://www.amphibians.org/
• Gascon, C., Collins, J.P. Moore, R.D., Church, D.R., McKay, J.E. and Mendelson III, J.R. (2007) Amphibian Conservation Action Plan. IUCN/SSC Amphibian Specialist Group, Gland, Switzerland and Cambridge, UK. Available at:
  http://www.amphibians.org/ASG/Publications_files/ACAP.pdf
• Amphibian Ark:
  http://www.amphibianark.org/