Records of Philippine Birds in the Critical Watersheds of Surigao del Norte, Northeastern Mindanao, Philippines

The Philippines is recognised as a global biodiversity hotspot with exceptionally high bird endemism. However, many ecologically important regions, including those in Surigao del Norte, remain poorly studied. This study recorded birds in Baoy, Can-agtiw, and Agas-as watersheds with notes on diversity indices and notable and threatened species from August to September 2023. We utilised direct observation along established transect lines and mist-netting methods to record birds in the three watersheds. A total of 63 bird species belonging to 35 families and 14 orders were documented, including 33 Philippine endemics (52.38%). Overall diversity (H’) was 3.101, and Baoy watershed recorded the highest number of individuals and richness (647 individuals with 44 spp.). Several locally threatened species were also documented, including two critically endangered species, i.e., Philippine hanging Parrot (Loriculus philippensis) and Blue-naped Parrot (Tanygnathus lucionensis); the endangered Mindanao Hornbill (Penelopides affinis); and five vulnerable species, i.e., Philippine Hawk-eagle (Nisaetus pinskeri), Writhed Hornbill (Rhabdotorrhinus leucocephalus), Philippine Dwarf Kingfisher (Ceyx melanurus), Southern Silvery Kingfisher (Ceyx argentatus), and the Mindanao Wattled Broadbill (Sarcophanops steerii). Although preliminary, the high number of endemic and threatened birds highlights the conservation value of these watersheds as important critical habitats. These findings emphasise the need for targeted conservation efforts, including immediate protection of these habitats and improving watershed monitoring strategies essential to safeguarding bird populations and ensuring long-term ecological sustainability.