The Glaucous Gull (Larus hyperboreus) is a large gull species that breeds in Arctic regions and winters at more temperate latitudes. With its pale gray body and wings and bright yellow eyes, the Glaucous Gull is a distinctive bird that stands out both at its breeding grounds and wintering sites. Understanding the range and distribution of Glaucous Gulls can provide important insights into their ecology and conservation. This article will provide a detailed overview of where Glaucous Gulls are found throughout their annual cycle.
Breeding Range
Glaucous Gulls breed in Arctic and subarctic regions of Alaska, Canada, Greenland, Iceland, northern Europe, and Russia. Their nesting range extends farther north than any other gull species.
In North America, breeding sites are located in:
- Alaska – Along the coasts of the Bering Sea, Chukchi Sea, and Beaufort Sea
- Canada – Arctic islands, Hudson Bay, Baffin Island, Labrador, Quebec, Northwest Territories, Nunavut, and Yukon
- Greenland – Coastal areas around the entire island
In Eurasia, breeding sites can be found in:
- Iceland – Coastal areas around the entire island
- Norway – Northern coastal areas and islands
- Russia – Arctic coastline, islands in arctic seas, Taymyr Peninsula, New Siberian Islands, Wrangel Island
- Svalbard – Islands in the arctic
Glaucous Gulls nest on inaccessible cliff ledges and rocky outcrops along the coast. They also nest on small islands in arctic rivers and lakes. The nests are built on the ground and consist of mounds of moss, grass, seaweed, or other vegetation.
Wintering Range
During the nonbreeding season, Glaucous Gulls migrate south to winter along coastlines and open waters at more temperate latitudes. Their winter range extends along:
- East coast of North America from Newfoundland to North Carolina
- West coast between Alaska and Washington
- Coastal regions of Iceland and western Europe
- Asia from Siberia to northern China and Japan
Some individuals also winter around the Great Lakes. Glaucous Gulls frequent harbors, fishing ports, beaches, and pack ice edges when foraging. They roost on beaches, docked boats, and ice floes.
Here is a table summarizing the primary breeding and wintering range of Glaucous Gulls:
Region | Breeding Range | Wintering Range |
---|---|---|
North America | Alaska, Canada, Greenland | East and west coasts of USA and Canada, Great Lakes |
Europe | Iceland, Norway, Svalbard, Russia | Coastal regions of Iceland and western Europe |
Asia | Russia | Siberia to northern China and Japan |
Migration Routes
Glaucous Gulls undertake lengthy seasonal migrations between their arctic breeding grounds and wintering areas at lower latitudes. They follow certain migration routes and stopover sites along the way:
- East coast North America – Migrate south along the Atlantic coast from the Canadian Arctic and Greenland to wintering sites farther south
- West coast North America – Follow the Pacific coast southbound from Alaska to Washington
- Eurasia – Migrate southward from arctic Russia and Scandinavia towards western Europe
- Asia – Follow coastline of eastern Russia and Siberia south towards China, Korea, and Japan
Notable stopover sites where large numbers congregate during migration include:
- St. Lawrence River, Quebec
- Great Lakes
- Glacier Bay, Alaska
- Point Barrow, Alaska
- Wrangel Island, Russia
Tracking studies using geolocators and satellite transmitters have yielded detailed maps of migration routes and connectivity between breeding and wintering sites for populations in North America and Eurasia.
North American Migration
- Birds from Alaska and northwest Canada winter along the west coast down to Washington
- Birds from Nunavut and Greenland migrate down the Atlantic coast to the northeast USA
- Interior Canadian arctic populations move south through the Great Lakes region
Eurasian Migration
- Russian arctic birds migrate southwest to Black Sea and Caspian Sea coasts
- Svalbard population winters in Britain, Ireland, and Norway
- Iceland birds disperse along coast from northern France to Iberian Peninsula
Vagrancy
While Glaucous Gulls primarily remain within their normal breeding and wintering ranges, vagrants occasionally turn up well outside expected areas, especially in autumn and winter. Vagrancy patterns include:
- West coast USA as far south as California
- Interior USA around Great Lakes and large reservoirs
- Western and central Europe away from the coast
- Inland China
Their large size, pale coloration, and bold streaking help identify Glaucous Gulls even far from typical range. Careful study is still required to distinguish vagrant Glaucous Gulls from similar Iceland Gulls in areas of overlap.
Global Distribution Map
This map provides an overview of the global distribution and movements of Glaucous Gulls throughout the year:
Key:
Breeding range shown in blue
Wintering range shown in red
Migration routes indicated by arrows
Habitat Preferences
Glaucous Gulls occupy the following habitats throughout their range:
Breeding
- Coastal cliffs, rocky islands, sea stacks
- Inland rocky outcrops near arctic lakes and rivers
- Low-lying tundra relatively free of snow
- Nest on ground in moss, grass, seaweed
Wintering
- Coastlines – beaches, harbors, fishing ports
- Offshore waters up to 300 miles out
- Pack ice edges
- Inland – large lakes, reservoirs, landfills
- Roost on docks, ice floes, buoys
Migration
- Coastlines
- Inland lakes and rivers
- Rest on sea ice
Glaucous Gulls require remote nesting sites near productive marine foraging areas during summer. In winter, they are flexible in exploiting both coastal and inland food sources.
Elevation Range
The elevation range occupied by Glaucous Gulls includes:
- Breeding sites – Sea level up to 300 m
- Wintering areas – Mainly coastal at sea level
- Vagrants may reach up to 1000 m elevation inland
They are not found breeding at high elevations in mountainous habitats, being limited to low Arctic coastal areas. During winter, the majority remain at sea level along coasts, though some wander widely inland and reach higher elevations occasionally.
Population Estimates and Trends
Global population estimates for Glaucous Gulls are around 300,000 to 400,000 individuals. Their numbers are distributed as follows:
- North America – 100,000 to 200,000 pairs
- Greenland – 10,000 to 20,000 pairs
- Iceland – 12,000 to 18,000 pairs
- Europe – 50,000 to 70,000 pairs
- Russia – 100,000 to 150,000 pairs
Local populations may fluctuate from year to year, but no significant long-term population trends have been identified globally. Numbers likely increased in parts of the range during the 20th century following human fishing activity and expansion of landfills as food sources. However, the species does not currently approach thresholds for conservation concern.
Conservation Status
The IUCN Red List classifies the Glaucous Gull as Least Concern. Populations appear stable and they occupy a wide global distribution. Their remote nesting habitat provides some protection against human disturbance. They are adaptable to utilizing human food sources in winter. While some populations are hunted or affected by contaminants, most seem to tolerate moderate levels of human impact without experiencing population declines. Continued monitoring is recommended to detect any emerging threats in the future.
Conclusion
In summary, Glaucous Gulls inhabit Arctic coastlines and islands during the breeding season before migrating long distances to winter at more southern latitudes in North America, Europe, and Asia. Their range spans latitudes from 80°N to 30°N. Though they primarily breed and winter along northern coasts, vagrants may turn up almost anywhere in the Northern Hemisphere during winter months. Careful assessment of distribution, movements, habitat use, and population trends is important for properly managing and conserving this circumpolar Arctic species. Ongoing tracking studies and population monitoring continue to provide valuable refinements to our understanding of where Glaucous Gulls occur around the globe throughout their annual cycle.