Great Black-backed Gull

Larus marinus

The great black-backed gull is the largest member of the gull and tern family Laridae. It is a very aggressive hunter, pirate and scavenger which breeds on the North Atlantic coasts and islands of northern Europe and northeastern North America. Southern populations are generally sedentary, while those breeding in the far north migrate farther south in winter. A few also move inland to large lakes and reservoirs. The adult has a white head, neck and underparts, dark blackish-grey wings and back, pink legs and the bill yellow with a red spot. Source

Where it is now

In the last 8 weeks this bird was recorded 6,229 times across 48 areas (each area is a 5 degree square).

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Movement and weather

Each season it is first heard regularly where daytime highs are around 14°C (typically 7 to 20°C, from 7 areas). That range is wide, so temperature alone does not explain when it turns up.

Over the weeks it was present in the past year, its centre in Europe ranged from 58°N in December to 71°N in May, about 1,500 km apart.

Arrival dates

The week it was first heard regularly in each region, after at least six weeks away. Dates differ from south to north, so a region has a range.

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Figures are effort corrected and come from automatic sound identification, which makes mistakes. How this is measured and how it compares with human observers.