By Ding Li Yong, Ayuwat Jearwattanakanok & Paul Insua Cao, 21st October 2021
Between the immense land masses of East Asia and Australia, South-east Asia lies near the geographical heart of the East Asian–Australasian Flyway, an important migratory corridor used by over 550 bird species. This includes several of Asia’s most threatened waterbirds. These species converge in South-east Asia in areas ecologically and geographically distant from their usual breeding grounds.
Spoon-billed sandpipers Calidris pygmaea raise their chicks in the wind-swept tundra of far north-east Russia, spotted greenshanks Tringa guttifer occupy the larch forests around Russia’s Sea of Okhotsk coast, black-faced spoonbills Platalea minor and Chinese egrets Egretta eulophotes breed on islets in the Yellow Sea off the Korean peninsula and China, great knots C. tenuirostris dwell on the pebbly tundra slopes of Siberian mountains, and far eastern curlews Numenius madagascariensis sing their haunting songs from south Siberian bogs. But on South-east Asia’s mudflats along the diverse coastlines of Myanmar, Malaysia, Thailand, Cambodia and Viet Nam, these species come together during their wintering period (September–April), or when they gather on their daunting, long-distance journeys to Indonesia and Australia.
Some of the best known of such sites lie within the inner Gulf of Thailand, an Important Bird and Biodiversity Area (IBA) that harbours extensive areas of coastal salt pans and intertidal flats. These species converge once again in Indonesia’s Batubara coast, Viet Nam’s Mekong Delta or Cambodia’s Koh Kapik mudflats. As a geographical confluence of so many migratory species, South-east Asia’s coastal wetlands are vital habitats and their protection is a conservation priority for migratory species in Asia.
In our review, we identified more than 180 IBAs that overlap with areas of coastal wetlands in the 10 countries of South-east Asia. Of these, 52 sites hold at least one threatened migratory species. However, far fewer of the IBAs identified actually overlap with protected areas such as nature reserves, wildlife sanctuaries or national parks. We found that there are large knowledge gaps regarding where many of the most important sites are located. This is demonstrated by ongoing studies including satellite tracking, and ground-surveys that we are leading. These studies continue to uncover areas of wetlands hitherto undocumented, yet holding threatened species or globally important numbers of migratory species.
The conservation of migratory waterbirds in South-east Asia faces three immediate challenges. Firstly, coastal wetlands that are globally important for migratory birds remain poorly represented in the region’s protected areas. For instance, few if any of the most important sites for shorebirds—the Philippines’ Manila Bay, Viet Nam’s Mekong Delta or Peninsular Malaysia’s Penang coast—are legally protected at the moment. Secondly, the direct threats faced by migratory shorebirds remain severe and may not be easily mitigated given the region’s rapid economic growth. There is a rapid increase in coastal land reclamation for competing uses such as wind farms, ports, airports and other infrastructure immediately threatening key sites. Thirdly, hunting of shorebirds at South-east Asian sites may lead to high mortality of shorebird populations, driving wider declines across the flyway.
Nevertheless, there are excellent models for migratory species conservation in the region. One of these is the Pak Thale Nature Reserve, a grassroots initiative led by the Bird Conservation Society of Thailand, a local non-government organization, to establish a protected area for threatened shorebirds. Under this initiative, wetlands are set aside for management and restoration with threatened shorebirds in mind, while local people and the local government are brought together to play a part through conservation groups, nature-based tourism, sustainable production of salt, and biodiversity monitoring. Lessons learnt from Pak Thale could inspire similar work in other sites or neighbouring countries.
There is potential to improve protection for the East Asian–Australasian Flyway’s shorebirds through efforts within South-east Asia’s 10 countries. Much of this may need to go beyond efforts such as planting mangroves. There is a need for more targeted investment in migratory species science, collaborations, coastal management and protected area designation. Above all, there is an urgent need for decision-makers and communities to realize that efforts for migratory shorebirds can also translate into long-term gains for both ecosystem services and livelihoods.
Acknowledgements: We thank Thattaya Bidayabha, Khwankhao Sinhaseni, Anuj Jain and Mike Crosby for their feedback and input. We are grateful to Nelson Khor and Toby Trung for the use of their images.
The article Conserving migratory waterbirds and the coastal zone: the future of Southeast Asia’s intertidal wetlands is available in Oryx—The International Journal of Conservation.