Catanduanes is an island of 182,300 ha which lies about 10 km off the tip of the Caramoan Peninsula in southern Luzon. The terrain on the island is hilly, particularly in the central portion, but the highest point only reaches just over 800 m. The substantial forests which remain in central Catanduanes are therefore all lowland dipterocarp in type, and are the largest remaining forest block in the whole of the Bicol Region. Forest is found above 490 m, and is estimated to cover a total of about 69,770 ha. It includes considerable areas of old growth dipterocarp forest (reported in 1997 to cover 5,876 ha), and closed-canopy forest in areas that show evidence of having been logged. These forest areas are the source of water for Catanduanes Province. One hydropower project is currently operational, that supplies power to urban areas of the island. The forest areas were proclamation as a Watershed Reserve in 1987 because of these important functions. The whole area is state-owned.
Many of the threatened and restricted-range birds of the Luzon Endemic Bird Area have been recorded on Catanduanes. Extensive lowland forests are reported to remain there, so it could support important populations of many of these birds. This is one of the few islands near Luzon where there has been a relatively recent record of Philippine Cockatoo, and Cream-bellied Fruit-dove appears to be particularly numerous there. Two of the restricted-range species are represented on Catanduanes by endemic subspecies, Luzon Bleeding-heart G. l. rubiventris and Grey-backed Tailorbird O. d. nilesi.
Non-bird biodiversity: Mammals recorded in this IBA include endemic species such as Philippine Nectar Bat Eonycteris robusta, Large Rufous Horsesheo Bat Rhinolophus rufus, Mottle-winged Flying Fox Pteropus leucopterus, Southern Luzon Giant Cloud Rat Phloeomys cumingi, Philippine Warty Pig Sus philippensis and Philippine Brown Deer Cervus mariannus. The area also harbors a significant number of endemic amphibians and reptiles including the Truncate-toed Chorus Frog Kaloula conjuncta, Rough-backed Forest Frog Platymantis corrugatus, Common Forest Frog Platymantis dorsalis, Giant Philippine Frog Rana magna, Woodworth’s Frog R. woodworthi, Mindoro Narrow-disked Gecko Gekko mindorensis, Philippine Calotes Calotes marmoratus, Common Flying Lizard Draco spilopterus, Common Burrowing Skink Brachymeles boulengeri, Two-digit Worm Skink Brachymeles samarensis, Northern Keel-scaled Tree Skink Dasia grisea, Yellow-striped Slender Tree Skink Lipinia pulchellum, Jagor’s Sphenomorphus Sphenomorphus jagori, Steere’s Sphenomorphus S. steerei, Black-Sided Sphenomorphus S. decipiens, Dog-faced Water Snake Cerberus rynchops, Philippine Cylindrical Snake Hologerrhum philippinum and Smooth-scaled Mountain Rat Snake Zaocys luzonensis. Globally threatened species, such as the Estuarine Crocodile Crocodylus porosus, the Endemic Sailfin Water Lizard Hydrosaurus pustulatus and Gray’s Monitor Lizard Varanus olivaceus) were also recorded in the area, and particularly noteworthy is the Catanduanes Narrow-mouthed Frog Kaloula kokacii, which is known to occur only on Catanduanes Island. Threatened marine turtles also occur in this IBA, such as the endangered Green Turtle Chelonia mydas and Olive Ridley Turtle Lepidochelys olivacea.
BirdLife International (2020) Important Bird Areas factsheet: Catanduanes Watershed Forest Reserve. Downloaded from http://www.birdlife.org on 25/09/2020.