Mt Halcon rises to 2,580 m, and is the third highest mountain in the Philippines. With its associated peaks, it includes the northernmost portion of the mountainous spine of the island of Mindoro. The Mt Halcon IBA extends for almost 60 km along the border between Mindoro Occidental and Mindoro Oriental. The western slopes of the mountains have a seasonal climate with wet and dry seasons, whereas the eastern slopes have an evenly distributed rainfall, leading to a large diversity of natural vegetation types. In the east, the lower slopes support dipterocarp forests, with lower montane forest between about 1,000 and 1,700 m, in places with large areas of bamboo thicket and landslides with herbaceous cover. Mossy forest is found from c.1,700 to 2,200 m, and alpine shrubs and heath above this around the peaks of the mountains. On the western slopes are “parang” vegetation with patches of dipterocarp forest and stands of Mindoro pine. In places the forest is naturally stunted (only c.10-12 m tall) with a highly uneven canopy and many needle-leaved trees, for example around Ilong Ridge. However, very large areas have been cleared and in 1991 kaingin (shifting cultivation) was found to be penetrating far up the most accessible valleys. In the area on Mt Ilong visited in that year, the lower edge of forest was at around 750 m. It descended somewhat lower on ridges and valley sides to the north and south, but was broken-canopied there. Between 750 and 850 m, logging by pit-saw was intensive and the forest very open, with trees up to 20 m tall and a dense scrub layer. Only above 850 m did natural primary forest of the lowland/lower montane transition type exist, extending up to 1,000 m with a canopy around 15 m tall. These mountains are a tribal territory of both the Iraya Mangyan and Alangan tribes, who have ancestral land claims on the area. Mt Halcon and its secondary peak and slopes are the watersheds of important riverine systems on the island, vital for agricultural productivity in the lowlands of northern Mindoro. The spectacular mountains in this IBA are popular with mountaineering clubs.
The Mt Halcon is one of the most important sites for biodiversity conservation on Mindoro. It includes the largest area of montane forest on the island, and is particularly important for the conservation of those threatened and restricted-range species of the Mindoro Endemic Bird Area which occur in montane forest, including the endemic Mindoro Imperial-pigeon and Mindoro Scops-owl. All of the lowland forest Mindoro endemics were recorded there in the past, but this habitat type has been much reduced, and Mt Halcon is now unlikely to support large populations of these threatened lowland species, other than Scarlet-collared Flowerpecker (which ranges up to relatively high altitudes).
Non-bird biodiversity: Mt Halcon is clearly important for mammals, but is poorly known. For example, a survey in 1992 discovered a new species of Maxomys (a genus previously only known in the Philippines from Palawan), and a new species of forest mouse Apomys gracilirostris was discovered in 1995. The highly endangered Tamaraw Bubalus mindorensis, which is endemic to Mindoro, is found on the south and west slopes of Mt Halcon. This IBA is also the only known locality for the Mindoro climbing rat Anonymomys mindorensis. The threatened endemic Philippine crocodile Crocodylus mindorensis has been recorded at one of the rivers inside this IBA. Mt Halcon is the type locality of the Mindoro tree frog Philautus schmackeri, which is confined to this island. A threatened butterfly species, Euploea tobleri mangyan, is known only from this IBA.
BirdLife International (2023) Important Bird Areas factsheet: Mount Halcon. Downloaded from http://www.birdlife.org on 09/02/2023.