Current view: Text account
Site description (2001 baseline):
Site location and context
North Negros Forest Reserve (NNFR) lies to the north of Mount Canlaon (PH063). It is an old forest reserve, mostly logged except for the two mountains, Mts. Silay and Mandalagan. These have extensive old growth forests on the higher slopes, and are connected by secondary forest. The area of NNFR is 80,454 ha, but only 16,687 ha of forest remains, of which c.75% is old growth and c.25% is secondary. The old growth is mainly above 1,000 m, but is found locally on very precipitous slopes at down to 700 m, and secondary forest is found at down to 400 m. The IBA is defined using the boundary of the remaining forest block, rather than the boundary of NNFR, as much non-forest land is included in that reserve.
Much of the forest in this IBA is montane, including mossy forest at the highest altitudes, most of which is primary. There are some areas of primary lowland dipterocarp forest on the lower slopes, and extensive areas of secondary lowland forest. The forest on slopes of Mt Mandalagan is heterogeneous owing to the many steep-sided gorges and ridges in the area, and is very broken. Extensive areas on the steep slopes are, however, not forest, but rather covered by grasses, tree-ferns and scrub.
This area is currently the largest tract of old growth forest left on Negros, which has only 4% of its original forest remaining. The secondary forest at 400 m is probably the only ‘true’ lowland forest remaining on Negros (although some forest survives at similar altitude in the Dumaguete City watershed area on Mt Talinis in PH066). This IBA forms the watershed of six major rivers in northern Negros that is the water source of 11 municipalities and cities and irrigates the islands' main rice production areas.
There have been several recent studies of the birds of Mt Silay and Mt Mandalagan (notably those of PESCP, the full details of which will be published shortly by Curio et al.), and many of the threatened and restricted-range species of the Negros and Panay Endemic Bird Area have been recorded there or reported by local people. This IBA includes the largest remaining areas of lowland forest on Negros, as well as extensive montane forests, and it is likely to prove to be very important for a number of threatened species, such as Negros-bleeding-heart, Visayan and Writhed-billed Hornbills and Visayan Flowerpecker.
Non-bird biodiversity: The NNFR harbours both endemic plants and animals. For plants these include hardwood tree species (Dipterocarps), palms, orchids, herbs and trees with medicinal value. Animals include Philippine Spotted Deer Cervus alfredi, Visayan Warty Pig Sus cebifrons and butterflies. A giant fruit bat, the critically endangered Negros Naked-backed Fruit Bat Dobsonia chapmani may already be extinct. Several additional endangered mammal species may be present, but no surveys have been conducted yet.
North Negros Forest Reserve (NNFR) lies to the north of Mount Canlaon (PH063). It is an old forest reserve, mostly logged except for the two mountains, Mts. Silay and Mandalagan. These have extensive old growth forests on the higher slopes, and are connected by secondary forest. The area of NNFR is 80,454 ha, but only 16,687 ha of forest remains, of which c.75% is old growth and c.25% is secondary. The old growth is mainly above 1,000 m, but is found locally on very precipitous slopes at down to 700 m, and secondary forest is found at down to 400 m. The IBA is defined using the boundary of the remaining forest block, rather than the boundary of NNFR, as much non-forest land is included in that reserve.
Much of the forest in this IBA is montane, including mossy forest at the highest altitudes, most of which is primary. There are some areas of primary lowland dipterocarp forest on the lower slopes, and extensive areas of secondary lowland forest. The forest on slopes of Mt Mandalagan is heterogeneous owing to the many steep-sided gorges and ridges in the area, and is very broken. Extensive areas on the steep slopes are, however, not forest, but rather covered by grasses, tree-ferns and scrub.
This area is currently the largest tract of old growth forest left on Negros, which has only 4% of its original forest remaining. The secondary forest at 400 m is probably the only ‘true’ lowland forest remaining on Negros (although some forest survives at similar altitude in the Dumaguete City watershed area on Mt Talinis in PH066). This IBA forms the watershed of six major rivers in northern Negros that is the water source of 11 municipalities and cities and irrigates the islands' main rice production areas.
Pressure/threats to key biodiversity
Owing to the rough topography and steepness of terrain, kaingin is encroaching into the montane forest here at a slower rate than elsewhere on Negros. However, many areas have been logged, and illegal commercial logging continues in the good quality residual timber stands. Two well-worn trails into the area are used to transport rattan and timber. The denudation of the lower slopes of Mts. Silay and Mandalagan has resulted in flash flooding during heavy typhoons. The most recent flooding in 1995 rendered hundreds homeless, destroyed agricultural land, sugar farms, rice plantations and fishpond holdings, and caused losses estimated at 60 million pesos.
Due to excessive hunting in the NNFR, larger birds are scarce, including hornbills and fruit pigeons.
Conservation responses/actions for key biodiversity
There have been several recent studies of the birds of Mt Silay and Mt Mandalagan (notably those of PESCP, the full details of which will be published shortly by Curio et al.), and many of the threatened and restricted-range species of the Negros and Panay Endemic Bird Area have been recorded there or reported by local people. This IBA includes the largest remaining areas of lowland forest on Negros, as well as extensive montane forests, and it is likely to prove to be very important for a number of threatened species, such as Negros-bleeding-heart, Visayan and Writhed-billed Hornbills and Visayan Flowerpecker.
The Negros Forest Ecological Foundation (NFEF, Inc.), in co-operation with the Provincial Environment Management Office (PEMO), has been running a conservation education project, to promote reforestation with native and exotic species, and support forest rangers. This started in 1986, and (although temporarily suspended) the focus of the project on NNFR has increased in the last five years.
Recently a NNFR Management Council was established, to consolidate all groups with an interest in the reserve into one united front. There is a need to strengthen this body and help it to develop protection and management measures. It has been proposed that this site should become a protected area under NIPAS, to conserve biological diversity and promote sound development. The work of the Management Council will complement the NIPAS process.
The biodiversity of NNFR is poorly known, and a project has been developed by PESCP (the Philippine Endemic Species Conservation and Research Project of the Frankfurt Zoological Society, conducted through the Animal Behaviour Research Group of Ruhr-Universität Bochum) to identify those components of biological diversity which are important for sustainable use, and monitor activities which may have an adverse impact on this diversity. This project aims to use research and management with public participation in order to monitor and avoid impacts that threaten biological diversity. Specific objectives include strengthening the NNFR Management Council; collecting baseline information on wildlife and the phenology and seed dispersal of forest trees by frugivores; investigating local agroforestry and livelihoods; and examining the potential of NNFR for ecotourism.
This IBA is within North Negros Forest Reserve, which was declared by Administrative Act No. 789 on 28 April 1935. It had an original area of 107,727 ha, but in 1946 this was trimmed down to 80,454 ha.
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Mount Silay and Mount Mandalagan (Northern Negros) (Philippines). Downloaded from
https://datazone.birdlife.org/site/factsheet/mount-silay-and-mount-mandalagan-(northern-negros)-iba-philippines on 23/12/2024.
