Common Gull vs Western Gull

In short

The Common Gull (Larus canus) and Western Gull (Larus occidentalis) can be distinguished primarily by size and plumage. The Western Gull is larger with a heavier build and a more robust bill. Common Gulls have a medium to pale gray mantle and generally darker eyes, while Western Gulls have a darker mantle and lighter eyes.

Identification tips

1. Look for the larger size and heavier build of the Western Gull. 2. Check the mantle color: darker in Western Gulls. 3. Note the eye color: generally darker in Common Gulls. 4. Observe the habitat: Western Gulls are more coastal.

Size

The Western Gull is larger and heavier than the Common Gull, with a more robust bill.

Plumage

Common Gulls have a medium to pale gray mantle and generally darker eyes. Western Gulls have a darker mantle and lighter eyes. Common Gulls often lack the white spot between gray and black on primaries, though this is variable.

Behaviour

Western Gulls are often found in colonies on islands and offshore rocks, while Common Gulls have a broader range of nesting sites.

Habitat

Common Gulls are more widespread, found in various habitats including inland areas, while Western Gulls are typically coastal, nesting on islands and offshore structures.