Mt Cagua lies at the northern end of the Sierra Madre mountains, in north-east Cagayan Province. The IBA includes two large blocks of old growth forest shown on recent forest cover maps, and extends south to the Mt Tabuan area, near Twin Peaks, north of Mt Cetaceo (PH014). Mt Cagua rises to just over 1,000 m, so the forest is mainly lowland in type, with limited areas of montane forest around the highest peaks.
Many of the threatened and restricted-range birds of the Luzon Endemic Bird Area have been recorded in or near to this IBA, including mainly lowland forest specialists. Many of these are known there only by historical records, including some from Cape Engaño at the northern extreme of the IBA. However, like other IBAs in the Sierra Madre, it is likely that the avifauna on Mt Cagua will prove to be similar to that of Northern Sierra Madre Nature Park (PH015). The relatively extensive forests in this IBA are likely to support significant numbers of Philippine Eagle. The record of the highly threatened Isabela Oriole is particularly notable.
Non-bird biodiversity: Baseline surveys of mammals and herpetofauna have not yet been conducted in the area. Populations of two northeast Luzon endemic rodents, the Sierra Madre Shrew-mouse Archboldomys musseri and the Northern Luzon Shrew-mouse Crunomys fallax have been recorded, and many other Luzon endemics may occur in the area.
BirdLife International (2020) Important Bird Areas factsheet: North Eastern Cagayan Protected Landscape and Seascape. Downloaded from http://www.birdlife.org on 26/10/2020.