Australian Migratory Birds: Nomads, Shorebirds and the Great Flyway

When people think of bird migration, they often picture the vast seasonal movements of the Northern Hemisphere—swallows returning to Europe in spring, geese flying south in V-formations. Australia, however, presents a fundamentally different picture. The continent’s bird movements are shaped by its unpredictable climate, its position at the southern end of a major migratory flyway, and the boom-and-bust cycles of its interior. Understanding Australian migratory birds requires understanding three distinct phenomena: true migration by shorebirds from the Northern Hemisphere, regular but varying movements by species like the Silvereye, and the uniquely Australian phenomenon of nomadism.

The East Asian-Australasian Flyway

The most dramatic and predictable bird movements in Australia involve migratory shorebirds. These species undertake one of the most extraordinary feats of travel in the animal kingdom, flying thousands of kilometres between breeding grounds in the Northern Hemisphere and non-breeding grounds in Australia. The majority of these birds use the East Asian-Australasian Flyway, a route spanning from New Zealand and Australia through Asia to Alaska, with crucial staging sites such as the mudflats around the Yellow Sea in China and Korea.

Most migratory shorebird species breed in northern China, Mongolia, Siberia and Alaska during June and July, then migrate to Australia for the non-breeding season. They leave the Northern Hemisphere around July and arrive in Australia from late August onwards, with adults of more southerly breeding species arriving first, followed by adults from farther north and then juveniles. Species such as the Curlew Sandpiper and Sharp-tailed Sandpiper typically arrive in Australia from August to November and depart for their breeding grounds in Siberia from March to mid-April. The Great Knot, Bar-tailed Godwit, and Eastern Curlew are among the many species that make this journey, with Roebuck Bay and Eighty Mile Beach in Western Australia regularly supporting over 500,000 birds at any one time.

[Menu:Australian Birds : Facts and Information]

• Australian Bird Conservation and Threats: Avifauna Under Pressure
• Australian Bird Species and Families: The Major Groups
• Australian Birds by Diet: From Nectar to Fish
• Australian Birds by Habitat: A Land of Parrots
• Behaviour and Adaptations: Nectar Feeding to Social Learning

The Birds and Parrots of Australia

The energy demands of migration are staggering. Shorebirds markedly increase their food intake rates to store fat as fuel, and over a period of as little as six weeks, they can almost double their weight and transform their appearance. Before departure, they reduce the size of digestive organs such as the liver, which are not necessary during flight, and store protein as a thick skin layer to repair muscle damaged during the journey. They can fly higher than 5,000 metres to find favourable winds.

Not All Australian Birds Migrate: The Nomadic Strategy

A crucial distinction must be made between true migration and nomadism. As early as 1885, Australian naturalist E.P. Ramsay observed that “strictly speaking we have no migration among our birds”—a statement that, while an overstatement given the shorebird flyway, captures the essential character of most Australian bird movements. Rather than following fixed seasonal routes, many Australian birds are nomadic, wandering in response to rainfall, flooding, or food availability.

This pattern is particularly pronounced among Australian waterfowl. Populations of Anatidae—ducks, geese and swans—do not migrate as they do in the Northern Hemisphere, but rather display typical nomadic traits, sometimes moving large distances across continental Australia in response to flooding or drought. The Australian Pelican can establish large breeding colonies at the edges of transient lakes, exploiting waterflows that bring large numbers of fish to ephemeral water bodies. Budgerigars, perhaps the most famous Australian nomads, display partial north-south movement patterns loosely coinciding with rainfall, and Emus in Western Australia show similar rainfall-driven movements, sometimes passing through good feeding grounds while moving towards recent rainfalls.

Nomadism is predominantly a southern hemisphere phenomenon and is particularly common among Australian birds, where boom-bust cycles drive resource fluctuations. Rather than displaying random opportunistic movements, Australian nomads such as finches and honeyeaters may display seasonal directionality and endogenously controlled behaviour consistent with that of long-distance migrants of the Northern Hemisphere.

Regular Migrants and Partial Migrants

Some Australian birds do undertake regular, predictable migrations. The Silvereye (Zosterops lateralis) migrates from Tasmania to as far as southern Queensland, though a 2024 study using 16 years of weather radar data revealed that “they might not all do that every year and sometimes they migrate shorter distances”. The Dollarbird breeds throughout eastern Australia and migrates mostly to New Guinea for the winter. Latham’s Snipe, a non-breeding migrant to south-eastern Australia, takes passage through northern Australia in late July to early August, arriving in south-eastern Australia between August and November, and leaves by mid-April back to Japan and Russia to breed.

The Fork-tailed Swift is another regular migrant, typically migrating to northern Australia and then travelling south around October, known for its high mobility while in Australia. These swifts are primarily aerial, rarely landing, and spend much of their time foraging in large flocks high above the canopy.

Threats to Migratory Birds

Migratory shorebirds face severe threats across their range. The greatest is habitat loss at key staging sites, particularly in the Yellow Sea, where tidal flats declined from 1.12 million hectares in the 1950s to 389,000 hectares by the 2000s—a loss of up to 65% over 50 years. The Saemangeum reclamation project in South Korea, which impounded approximately 29,000 hectares of tidal flats behind a 33-kilometre sea-wall in 2006, supported at least 330,000 migratory shorebirds prior to reclamation, including 30% of the world population of Great Knot. Following completion, an estimated 130,000 migratory shorebirds disappeared from the flyway population within the first two years, and 300,000 had disappeared by 2013, including an estimated 104,000 Great Knots.

Analysis of shorebird population trends in Moreton Bay over 15 years found that abundances of at least seven migratory shorebird species declined significantly by between 43% and 79%, while resident shorebird species showed no significant trends. Australia-wide decreases have been recorded in 12 of 19 migratory shorebird species, with estimated annual rates of decline of between 1.98% and 9.53%.

In Australia, threats include human disturbance at feeding and roosting sites, habitat loss and degradation from pollution, changes to water regimes, and the spread of mangroves into mudflats and coastal saltmarshes.

Conclusion

Australian migratory birds present a complex picture. The shorebirds that travel from Siberia and Alaska along the East Asian-Australasian Flyway represent true migration on a spectacular scale, while species like the Silvereye and Dollarbird undertake more modest but regular seasonal movements. Yet the dominant pattern among Australian birds is nomadism—a strategy of wandering in response to the continent’s unpredictable rainfall and resource fluctuations. Whether following ancient flyways across oceans or drifting across the inland in search of ephemeral plenty, Australia’s migratory birds are shaped by the unique rhythms of the southern continent.