Dumaran Island was one of the earliest Spanish settlements in Palawan. Hence, land conversion from forest to agriculture started quite early, and forest cover is much lower than in most other parts of the archipelago. All natural terrestrial ecosystems in Dumaran are tree-dominated. On Dumaran Island only few small and isolated forest patches remain, none of them larger than 103 ha. The most abundant formation is evergreen and semi-evergreen lowland forest.
However, the remaining forest patches are extremely important for biodiversity conservation. Three critically endangered species occur in the same habitat: Philippine Cockatoo, Philippine Pangolin and Palawan Forest Turtle. Ornithological surveys so far yielded 136 species from the island, many of which are threatened or endemic. There is a particularly rich cavity-nesting bird assemblage found on the island, with all four woodpeckers and all three parrot species known from Palawan present there. The globally threatened Palawan Hornbill still occurs in good numbers in the forests, and this species was recently chosen as the municipalities’ flagship species.
Katala Foundation currently co-manages two areas on the island: The Dumaran Island Critical Habitat, including the Omoi and Manambaling Cockatoo Reserves (the first of its kind in Palawan) and the traditional cockatoo roost site in Lagan. A Local Protected Area Management Committee (LPAMC) functions as its management body and a management plan is in preparation.
Aside from the nest protection scheme for the cockatoo, this has been expanded to other cavity-nesting bird species of conservation concern. Artificial nest boxes are currently field-tested for Palawan Hornbill and other cavity nesters. Since the cockatoo population seems to be overaged, with low reproductive rates observed, the existing cockatoo population is supplemented with birds rescued or confiscated from other project sites, after careful quarantine and health screening. Most of the released birds do well in the wild, and readily integrate into the wild flock.
An important component of the conservation work on Dumaran is the reforestation effort within the critical habitat. Native trees are propagated in one main and several satellite nurseries, and corridor and buffer zone of the protected area is continuously replanted.