The study presents the results of the bird assessments in the Lake Mainit Watershed from August to September 2013, March to May 2014, and September to November 2017. The study was part of the Protected Area Suitability Assessment (PASA) of the proposed Lake Mainit Protected Area establishment. A total of 138 species from 56 families were recorded from the ten sampling sites. About 45% were endemic and 13% within the threatened classification of the International Union for Conservation of Nature (IUCN). Specifically, 8% of the birds were categorized near-threatened, and 4% were vulnerable. The recorded bird species constituted about 20% of the birds in the Philippines and were higher than those recorded in Eastern Mindanao Biodiversity Corridor (EMBC) and Mt. Hilong-hilong. However, the existence of this avifauna is continuously threatened by anthropogenic factors. Resource extraction was apparent, which includes timber and other forest product harvesting. In some sampling sites, small scale mining was evident supporting the livelihood of the people. Several sectors and groups also pose a conflict in resource use like the Mineral Production Sharing Agreement (MPSA) and Certificate of Ancestral Domain Tenure (CADT). Nonetheless, the presence of unique and threatened species of birds supports the importance of establishing the site as a Protected Area (PA). Hence, proper planning and management measures are imperative to address the conflict between conservation and the people's livelihood.