Current view: Text account
Site description (2001 baseline):
Site location and context
Siburan is the largest tract of lowland forest known on Mindoro. It is adjacent to the large Sablayan penal colony, which restricts access to the forest and therefore provides some degree of protection. The forest is about 30 km south-east of Sablayan, with forest on the south and east edge of the penal colony. This forest is contiguous with the patchy forests on the limestone ridge running north from Malpalon (PH043). In 1991, it was estimated that about 1,500 ha of lowland forest remains, with a similar area of unvisited montane forest further east. The lowland forest is generally closed canopy with trees of up to 25 m or more and a relatively open forest floor. There are fewer limestone outcrops causing less disruption to the canopy than at Malpalon. The small Lake Lubao borders the forest.
Most of the threatened and restricted-range lowland forest birds of the Mindoro Endemic Bird Area have been recorded recently at Siburan. It is almost certainly the largest and most important lowland forest site on Mindoro, particularly given the current relatively low level of disturbance there. The protection of this IBA probably represents the best opportunity to prevent the extinction of the highly threatened Mindoro Bleeding-heart, Black-hooded Coucal and Mindoro Hornbill. Lake Lubao, bordering the forest, holds a few waterbirds.
Non-bird biodiversity: This IBA is likely to support endemic small mammals, etc., but surveys of the mammalian fauna and herpetofauna are yet to be conducted there.
Siburan is the largest tract of lowland forest known on Mindoro. It is adjacent to the large Sablayan penal colony, which restricts access to the forest and therefore provides some degree of protection. The forest is about 30 km south-east of Sablayan, with forest on the south and east edge of the penal colony. This forest is contiguous with the patchy forests on the limestone ridge running north from Malpalon (PH043). In 1991, it was estimated that about 1,500 ha of lowland forest remains, with a similar area of unvisited montane forest further east. The lowland forest is generally closed canopy with trees of up to 25 m or more and a relatively open forest floor. There are fewer limestone outcrops causing less disruption to the canopy than at Malpalon. The small Lake Lubao borders the forest.
Pressure/threats to key biodiversity
The future of Siburan is not secure, although there is presumably some degree of protection afforded by the proximity of the penal colony. The prisoners have some impact on the forest, as they use it for the collection of firewood, rattan and bamboo, and for snaring birds. Species such as Black-hooded Coucal may be confined to undisturbed areas of forest where dense tangles of vines and rattans are found, and this is being slowly cleared away from the forest nearest to the prison, due to the collection of rattan for furniture production by the prisoners. A large tree felled at this location was being milled on site for either furniture or building purposes. However, in general there are minimal signs of human activity in the forest, with very few paths and no logging reported.
A serious threat is posed to Siburan by encroaching slash-and-burn cultivation (kaingin), both by local people and the refugees. The influence of the penal colony has so far kept such deforestation to a minimum, but the forest has no formal protection and is likely to come under increasing pressure in the future.
Conservation responses/actions for key biodiversity
The Sablayan forest is under the jurisdiction of the Department of Justice, and an integrated social forestry project is running in the region.
It has been proposed that the forests of Siburan should be established as a new protected area, and it has been suggested that the increasing outside interest shown in the birds of Siburan could provide greatly needed encouragement to conservation in the area. This site provides a unique opportunity to see at least four species that are almost impossible to find anywhere else in the world.
Not officially protected.
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Mount Siburan (Philippines). Downloaded from
https://datazone.birdlife.org/site/factsheet/mount-siburan-iba-philippines on 22/11/2024.
