Duft ducks at the Lake Mainit [EAAF158] ⓒ Godofredo Jakosalem
Three ecologically important wetlands in the Philippines have been newly designated as Flyway Network Sites (FNS) under the East Asian–Australasian Flyway Partnership (EAAFP), recognising their vital role in supporting migratory waterbirds along one of the world’s most significant flyways. The designations were formally announced on 10 November during the welcome dinner ceremony of the 12th Meeting of Partners (MOP12), where representatives of the sites were presented with official FNS certificates by the Chair of the Partnership.
The newly designated sites—Lake Mainit [EAAF158], Agusan Marsh Wildlife Sanctuary [EAAF159] and Sibugay Wetland Nature Reserve [EAAF160]—become the Philippines’ fifth, sixth, and seventh Flyway Network Sites. Their addition strengthens the Flyway Site Network, which consists of wetlands of global importance that provide essential habitats for migratory species along the East Asian–Australasian Flyway (EAAF).
Lake Mainit, located within the Mt Hilong-hilong Key Biodiversity Area, is the fourth largest and deepest lake in the Philippines. Covering nearly 14,000 hectares, the lake provides essential hydrological services, including groundwater recharge, flood control, and sediment capture. It supports exceptionally high numbers of waterbirds as a key feeding and stopover site for migratory species, with counts in some years exceeding 50,000 individuals. Regularly recorded species include the Little Egret (Egretta garzetta), Wandering Whistling Duck (Dendrocygna arcuata) and Tufted Duck (Aythya fuligula), with the site supporting more than 1 per cent of the Tufted Duck’s global population.
Lake Mainit [EAAF158] ⓒ Department of Environment and Natural Resources of the Philippines (DENR)
The Agusan Marsh Wildlife Sanctuary (AMWS) is an extensive inland wetland situated in the central Agusan River Basin. Characterised by shallow lakes and ponds, swamps, marshes, peatlands and areas subject to seasonal flooding, the marsh plays a crucial role in natural water storage, flood regulation and groundwater recharge. AMWS also serves as a vital habitat and stopover site for migratory waterbirds, offering abundant feeding grounds and secure roosting areas. Species such as the Little Egret (Egretta garzetta), Intermediate Egret (Ardea intermedia), Marsh Sandpiper (Tringa stagnatilis) and Whiskered Tern (Chlidonias hybrida) are commonly recorded. Surveys have documented more than 20,066 individual waterbirds, underscoring the sanctuary’s regional and international conservation significance.
Agusan Marsh Wildlife Sanctuary [EAAF159] ⓒ DENR
Also included in the latest round of designations is the Sibugay Wetland Nature Reserve, which encompasses forested wetlands, intertidal flats, and marine waters within Sibugay Bay. The reserve supports a wide diversity of shorebirds and waterbirds, including eight globally threatened species, comprising four Endangered and four Vulnerable species. Endangered species recorded at the site include the Far Eastern Curlew (Numenius madagascariensis), Great Knot (Calidris tenuirostris), Siberian Sand Plover (Charadrius mongolus), Black-faced Spoonbill (Platalea minor) and Sharp-tailed Sandpiper (Calidris acuminata), reinforcing the site’s importance as a migratory stopover and feeding area along the flyway.
The designation of these new Flyway Network Sites strengthens the EAAFP Flyway Site Network, which refers to the network of internationally important wetlands used by migratory waterbirds throughout the flyway. The framework aims to secure sites that meet agreed criteria, such as supporting large numbers of migratory waterbirds, including threatened and near-threatened species, or functioning as key staging areas during migration.
The ecological, social, and conservation values of Lake Mainit, Agusan Marsh Wildlife Sanctuary, and Sibugay Wetland Nature Reserve are particularly significant. As refuges for migratory waterbirds facing widespread habitat loss and population declines across the flyway, their designation reflects growing recognition of the Philippines’ wetlands as critical links in migratory pathways that sustain waterbird populations across East Asia–Australasian Flyway.
Red-necked Stint with legflags at Sibugay Wetland Nature Reserve [EAAF160] ⓒ Dante Oporto
Lake Mainit [EAAF158]
- Site Information Sheet: https://eaaflyway.org/wp-content/uploads/2025/12/EAAF158_Lake-Mainit-SIS.pdf
- More photos: https://flic.kr/s/aHBqjCE5uS
Agusan Marsh Wildlife Sanctuary [EAAF159]:
- Site Information Sheet: https://eaaflyway.org/wp-content/uploads/2025/12/EAAF159-Agusan-Marsh-Wildlife-Sanctuary-SIS.pdf
Sibugay Wetland Nature Reserve [EAAF160]
- Site Information Sheet: https://eaaflyway.org/wp-content/uploads/2025/12/EAAF160-Sibugay-Wetland-Nature-Reserve-SIS.pdf
- More photos: https://flic.kr/s/aHBqjCE8L7
