Sibuyan is a crescent-shaped island of Romblon Province, Philippines. It has an area of 445 sq km. Primary forests cover 140 sq km, or 33% of the land area of Sibuyan. However, most of the lower altitude forest has been logged or is secondary. Mt Guiting-guiting Natural Park (equivalent to the IUCN category of National Park) was established to protect these forests, which are mainly in the centre and north of the island, and covers an area of about 157 sq km out of Sibuyan’s total area of 445 sq km. The Park is remarkable for its outstandingly scenic landscape with twin towering peaks set amidst closed canopy forests. Its forests remain largely intact, and include the entire elevational gradient from lowland dipterocarp forest (at 200-900 m) and mangroves, through montane forest (above 700 m) to mossy forest, heathland and montane grassland around the peaks. The whole island is likewise proclaimed as an initial component as protected area as a mangrove forest swamp reserve.
The island has lived with its isolation from the rest of the world since its birth. Never in its geological history has it ever been connected with any part of the Philippine archipelago. Seismic forces pushed up a 2,000-meter peak from the earth’s crust, forming a series of smaller peaks and slopes. The peak is Mt. Guiting-guiting (literally means “the saw-toothed mountain”, in reference to its jagged ridge. And because of the steep slopes, much of its original forest remains untouched), and the rest is the island as we find it today.
Known for its biodiversity, Sibuyan has been dubbed by local and international natural scientists as the Galapagos of Asia. Its significance to the world’s animal and plant diversity cannot be taken lightly—one of the richest spots in the world in terms of density, diversity and endemism of flora and fauna.
Exact figures of plant species are hard to give, as biologists continue to stumble upon species yet unidentified by the scientific community. In one study, the National Museum identified 1,551 trees in a single hectare, with 123 species of trees. Of this number, 54 are found nowhere else in the world. Sibuyan’s forest has been proclaimed as the world’s densest forest.
There are estimated to be 700 vascular plant species on the island.
There are 131 species of birds that share the skies with ten species of fruit bats, and the plethora of land-dwelling mammals, reptiles, and rodents have yet to be fully catalogued. It is likely that several of these birds will prove to have important populations in the extensive forests of Mt Guiting-guiting National Park. Three subspecies are endemic to Sibuyan, Colasisi Loriculus philippensis bournsi, Philippine Pygmy-woodpecker (Dendrocopos maculatus ménagei) and Orange-bellied Flowerpecker (Dicaeum trigonostigma sibuyanicum), all of which were recorded there in the early 1990s, and two more to Sibuyan and other nearby islands. Five species of mammals (all threatened) (one fruit bat and four rodents) are endemic to Sibuyan, and the critically endangered fruit bat Nyctimene rabori occurs there.
Scientists have yet to fully catalog the land-dwelling mammals, reptiles, and rodents that can be found in the island.