This IBA includes the remaining forests of the Cuernos de Negros, an extensive mountain range in southern Negros Oriental province. The highest peaks are around Mt Talinis, which rises to 1,864 m, and are still covered with primary mid-mountain and mossy forest. On the eastern slopes of the mountains continuous forest descends to 1,100 m, and there are degraded patches on steep slopes down to 850 m. The forest is primary but clearance for agriculture has been extensive in the valleys and on some hillsides, reaching 1,300 m. To the north of Mt Talinis there are substantial areas of primary and secondary lowland dipterocarp forest around the twin lakes at Balinsasayao, with some patches of secondary growth in recently cleared areas. These two small crater lakes are separated by a narrow mountain ridge, and situated in a hollow between four mountains, Mt Mahungot to the south, Mt Kalbasaan to the north, Mt Balinsasayao to the east and Mt Guintabon to the west of the Twin Lakes. Lake Balinsasayao lies to the north-west of the ridge and Lake Danao to the south-east. Some lowland forest remains in the Dumaguete City watershed at c.300-500 m. In the past, the most extensive tracts of lowland forest were on the western side of the Cuernos de Negros, but there is little recent information on the status of the forests in this insurgency-troubled and remote part of the IBA. The area around Mt Talinis is under the jurisdiction of the Philippine National Oil Corporation (PNOC), which has a large geothermal power plant lower down the mountain. Negros Geothermal Reservation covers 133,000 ha, of which an area of 4,096 ha was reported to be forested in 1987. The forests of this IBA are the watershed for all of southern Negros Island. The Twin Lakes area is sparsely populated by subsistence farmers.
Most of the threatened and restricted-range species of the Negros and Panay Endemic Bird Area have been recorded in the Cuernos de Negros. The extensive montane forests there support important populations of several of these species, notably Negros Striped-babbler, which remains locally common in this IBA and is otherwise only known by a single record in Mt Canlaon National Park (PH063). The low altitude forests around Lake Balinsasayao and in the poorly known western section of the Cuernos de Negros may prove to support important populations of several of the lowland and lower montane specialists which are endemic to this EBA, including Visayan and Writhed-billed Hornbills, White-winged Cuckoo-shrike, Flame-templed Babbler, White-throated Jungle-flycatcher and Visayan Flowerpecker.
Non-bird biodiversity: The critically endangered Philippine Spotted Deer Cervus alfredi, Visayan Warty Pig Sus cebifrons and Negros Shrew Crocidura negrina occur in this IBA. This area includes some of the last known habitat for the Negros endemic Naked-backed Fruit Bat Dobsonia chapmani (which may already be extinct). It also supports populations of other large fruit bats, including the critically endangered Philippine Tube-nosed Fruit Bat Nyctimene rabori, the endangered Golden-crowned Flying Fox Acerodon jubatus and the vulnerable Little Golden-mantled Flying Fox Pteropus pumilus.
BirdLife International (2020) Important Bird Areas factsheet: Cuernos de Negros. Downloaded from http://www.birdlife.org on 19/01/2020.