Migratory Flyway Conservation: Protecting Birds Along Their Entire Route
A migratory shorebird that breeds in the Siberian Arctic, stages in South Korea, and winters in Australia crosses the jurisdictions of at least four countries in each annual cycle. If any of the critical stopover sites in that journey is degraded — drained, reclaimed, or sufficiently disturbed during the fuelling period — the bird cannot complete its migration. The consequences propagate: breeding populations decline; the effect appears not at the stopover site, where the bird was only visiting, but at the breeding ground and wintering area, thousands of kilometres away. Migratory bird conservation therefore cannot be accomplished by any single country acting alone.
The flyway concept
The world's migratory landbird, waterbird, and shorebird populations are organized into flyways — broad geographic corridors that channel migration between breeding and wintering grounds. Eight major flyways are recognized globally: the East Atlantic Flyway, the African-Eurasian Flyway, the Central Asian Flyway, the East Asian-Australasian Flyway, the Mississippi Flyway, the Central Americas Flyway, the Pacific Americas Flyway, and the Atlantic Americas Flyway. These are not rigid channels but probabilistic corridors through which most individuals of a given population travel.
The flyway concept is operationally important because it defines the conservation unit. A species declining on its wintering ground in West Africa due to wetland drainage cannot be saved by protecting its breeding ground in Iceland. The problem and its solution are geographically separate. Coordinated management across the flyway is the only complete response.
East Asian-Australasian Flyway: the most threatened
The East Asian-Australasian Flyway (EAAF) is widely regarded as the flyway under greatest pressure. It connects breeding grounds across Russia, Alaska, and the Canadian Arctic with wintering areas in Southeast Asia, Australia, and New Zealand, passing through staging areas along the Yellow Sea coast of China and South Korea. The Yellow Sea intertidal mudflats are the critical fuelling bottleneck: shorebirds including Bar-tailed Godwit (Limosa lapponica), Great Knot (Calidris tenuirostris, Endangered), and Spoon-billed Sandpiper (Calidris pygmaea, Critically Endangered) depend on the extraordinary productivity of Yellow Sea mudflats to accumulate the fat reserves needed to complete their migrations.
Intertidal reclamation in China and South Korea has eliminated an estimated 65 percent of Yellow Sea mudflat area since the 1950s. The consequences have been tracked in annual population surveys: Great Knot populations have declined by approximately 75 percent since the early 1990s. The Saemangeum reclamation in South Korea, which converted 400 square kilometres of critical intertidal habitat to an industrial zone between 2006 and 2010, is one of the most clearly documented single conservation disasters in the history of migratory bird research. Population declines in EAAF shorebirds, documented by researchers in Australia and New Zealand, were attributable to events in South Korea.
East Atlantic Flyway: waterfowl and waders
The East Atlantic Flyway connects Arctic-breeding waders and geese with wintering grounds along the Atlantic coast of Europe and West Africa. The Wadden Sea — a 14,000-square-kilometre intertidal system shared between the Netherlands, Germany, and Denmark — is the most critical staging site. Wadden Sea National Parks in all three countries are UNESCO World Heritage Sites; their combined designation represents one of the clearest examples of flyway-level site protection.
The Icelandic-breeding population of Black-tailed Godwit (Limosa limosa islandica) migrates through Britain and Iceland and winters in estuaries from Portugal to Senegal. Research using satellite-tracked birds has shown that individual godwits use a small number of staging sites with remarkable fidelity across years — returning to the same estuary, sometimes the same meadow. This site fidelity makes individual key sites irreplaceable; losing any one of them impacts the population disproportionately.
The AEWA framework
The African-Eurasian Migratory Waterbird Agreement (AEWA) is a legally binding treaty under the Convention on Migratory Species (CMS) that covers 255 species of waterbirds. Signatory countries commit to species conservation plans, site protection, hunting regulation, and population monitoring. AEWA has produced International Species Action Plans for the most threatened waterbirds in the flyway, including the Sociable Lapwing (Vanellus gregarius, Critically Endangered) and the Slender-billed Curlew (Numenius tenuirostris, Critically Endangered, possibly extinct).
The East Asian-Australasian Flyway Partnership (EAAFP) operates as a non-binding regional arrangement, which reflects the political realities of coordinating conservation across China, North Korea, and other regional states. Despite the softer legal framework, EAAFP has produced coordinated site networks, shared survey protocols, and the political pressure that contributed to South Korea's designation of several Nakdong River estuary sites as Ramsar wetlands.
What birders can contribute
Population monitoring of migratory species depends on dedicated volunteer observers at wintering and staging sites. Shorebird count programs — WeBS in the UK, Shorebird 2020 in Australia, NANPAN in North America — produce the population estimates that feed flyway-level assessments. Submitting eBird checklists from staging sites, with accurate counts of species and effort data, adds to the density of observations that researchers use to model population trends across the flyway.
The policy and international framework
Migratory bird conservation operates across national boundaries by definition — a species can be fully protected in its breeding range while being hunted unsustainably in its wintering range or dying in unmarked transmission lines during migration. This international dimension requires policy frameworks that no single government can provide, which is why global conventions are the foundation of flyway conservation.
The Convention on Migratory Species (CMS), also known as the Bonn Convention, provides the legal basis for international cooperation on migratory species protection. CMS Agreements — legally binding instruments for specific species groups — include the African-Eurasian Migratory Waterbird Agreement (AEWA), which covers 255 waterbird species in 119 range states, and the Memorandum of Understanding on the Conservation of Migratory Sharks, which provides analogous frameworks for marine species.
The most concrete achievements of flyway conservation in recent decades have been in the East Atlantic Flyway, where the Wadden Sea — designated as a UNESCO World Natural Heritage Site in 2009 and extended in 2014 to cover the full Dutch-German-Danish coast — provides a coordinated management framework for the most critical shorebird staging habitat in Europe. The Trilateral Cooperation on the Protection of the Wadden Sea coordinates Germany, Netherlands, and Denmark in synchronized monitoring and habitat management.
The East Asian-Australasian Flyway Partnership (EAAFP) provides coordination across 37 partner countries for a flyway that has experienced the most severe shorebird declines of any flyway globally — primarily due to tidal flat reclamation in China and South Korea. The EAAFP's site network identifies critical staging areas and works with governments on protection and restoration.
Illegal bird killing in the Mediterranean remains one of the most politically difficult flyway conservation challenges. BirdLife International estimates that 25 million birds are killed illegally in the Mediterranean each year, predominantly by shooting and trapping in Malta, Cyprus, Egypt, Lebanon, and parts of Italy. The Committee Against Bird Slaughter (CABS) conducts monitoring and anti-poaching operations across the Mediterranean killing hotspots.
The North Atlantic Flyway and seabird routes
Seabird migration follows oceanographic features rather than continental corridors — the thermal fronts, upwelling zones, and productive current margins that concentrate fish. The North Atlantic Flyway used by Arctic Tern (Sterna paradisaea) — which migrates from breeding grounds in the high Arctic to wintering grounds in the Southern Ocean, a round trip of 90,000 kilometres — is one of the longest annual migrations of any animal on Earth. Tracking studies using geolocators have mapped the routes precisely, showing that most birds follow the prevailing wind systems in figure-eight loops rather than direct routes.
The conservation implications for seabirds on these routes involve not just staging and breeding site protection but management of the fisheries that their food chains depend on. Bycatch in longline fishing operations is the primary mortality source for many albatross species; the Agreement on the Conservation of Albatrosses and Petrels (ACAP) coordinates seabird bycatch reduction with fishing nations.