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Location Philippines, Region IV
Central coordinates 120o 55.00' East  12o 48.00' North
IBA criteria A1, A2
Area 5,000 ha
Altitude 50 - 400m
Year of IBA assessment 2001

Haribon Foundation

Site description 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.

Key Biodiversity 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.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Philippine Duck Anas luzonica resident  1990-1999  present  A1  Vulnerable 
Mindoro Bleeding-heart Gallicolumba platenae resident  1990-1999  present  A1, A2  Critically Endangered 
Spotted Imperial-pigeon Ducula carola resident  1950-1959  present  A1  Vulnerable 
Black-hooded Coucal Centropus steerii resident  1990-1999  present  A1, A2  Critically Endangered 
Mindoro Hornbill Penelopides mindorensis resident  1990-1999  20 individuals  A1, A2  Endangered 
Scarlet-collared Flowerpecker Dicaeum retrocinctum resident  1990-1999  common  A1  Vulnerable 

IBA Monitoring

2015 very high very unfavourable medium
Good - based on reliable and complete / representative data

Biological resource use hunting & collecting terrestrial animals - unintentional effects (species is not the target) happening now whole area/population (>90%) moderate to rapid deterioration very high
Climate change and severe weather habitat shifting and alteration likely in long term (beyond 4 years) whole area/population (>90%) slow but significant deterioration medium
Human intrusions and disturbance work and other activities happening now small area/few individuals (<10%) slow but significant deterioration low
Natural system modifications dams & water management/use - abstraction of surface water (agricultural use) happening now some of area/population (10-49%) slow but significant deterioration medium

Forest   0 0 very poor (< 40%) moderate (70-90%) very unfavourable

Most of site (50-90%) covered (including the most critical parts for important bird species)  A management plan exists but it is out of date or not comprehensive  Substantive conservation measures are being implemented but these are not comprehensive and are limited by resources and capacity  medium 


IUCN habitat Habitat detail Extent (% of site)
Wetlands (inland)   -
Forest   -
Artificial - terrestrial   -

Protection status Not officially protected.

Further web sources of information 

Alliance for Zero Extinction (AZE) species/site profile. This site has been identified as an AZE due to it containing a Critically Endangered or Endangered species with a limited range.

References Brooks et al. (1995b); Dutson et al. (1992); Evans et al. (1993a).

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Recommended citation  BirdLife International (2015) Important Bird and Biodiversity Area factsheet: Mount Siburan. Downloaded from on 27/11/2015

To provide new information to update this factsheet or to correct any errors, please email BirdLife