Canadian Arctic Bird Surveys Reveal Far Greater Populations Than Expected
Two decades of systematic fieldwork across tundra habitats have reshaped our understanding of abundance and distribution, highlighting the overlooked importance of “dry” habitats for millions of breeding birds
First comprehensive Arctic-wide effort
Between 1994 and 2018, biologists carried out more than 2,500 ground-based surveys across the Canadian Arctic. These represent the first systematic, stratified surveys of bird abundance and distribution at such a scale, covering wet sedge meadows, moist tundra, and the vast expanses of drier ground. Until now, population estimates for many species relied heavily on partial counts or expert opinion, often with margins of error spanning an order of magnitude.
The new work demonstrates that most shorebird species are far more numerous than previously thought. In many cases, estimates were several times higher than earlier figures. Six species alone – Semipalmated Sandpiper Calidris pusilla, Red Phalarope Phalaropus fulicarius, White-rumped Sandpiper Calidris fuscicollis, Pectoral Sandpiper Calidris melanotos, American Golden-Plover Pluvialis dominica and Red-necked Phalarope Phalaropus lobatus – each exceeded 3 million individuals in Arctic Canada.
Dry tundra holds unexpected importance
Shorebird densities were, as expected, far higher in wet and moist tundra, but the huge areal extent of dry habitats meant they supported over 40% of the total shorebird population. These areas, often dismissed as marginal, in fact shelter vast numbers of birds spread at low densities across the landscape. For landbirds such as the Lapland Longspur Calcarius lapponicus, dry habitats were dominant, with this single species estimated at over 80 million individuals – more than the next four most numerous species combined.
Population totals on an immense scale
Altogether, the surveys suggest around 263 million birds breed in the Canadian Arctic each year. Shorebirds contributed about 46 million, waterfowl another 46 million, seabirds and waterbirds around 5 million, and landbirds an immense 165 million. For many species, these are the first survey-based estimates ever produced for Arctic Canada. Some groups, including loons Gavia spp. and jaegers Stercorarius spp., have never previously had abundance estimates spanning their Canadian Arctic ranges.
Conservation implications
These revised estimates carry major ramifications for conservation programmes that designate key sites based on the proportion of a species’ population present. Many wetlands and coasts previously deemed of international significance may now fall below percentage thresholds, not because they host fewer birds, but because the populations are larger than once believed. At the same time, the recognition that huge fractions of populations occupy dry tundra raises new questions about how to monitor and protect birds breeding in such dispersed, low-density habitats.
Looking ahead
The surveys exceeded expectations in terms of precision and coverage, and repeat visits are now beginning to document population changes over time. Early results suggest declines for some northerly species and northward range shifts linked to climate warming. By establishing a robust baseline, these surveys provide an essential foundation for tracking Arctic bird populations into a future of rapid environmental change. They also offer a rare piece of good news: many Arctic shorebirds are more numerous than conservationists had dared to hope – though still vulnerable to accelerating declines along their migratory pathways.
September 2025
Share this story
