Caspian Gull vs Great Black-backed Gull

In short

The Caspian Gull and Great Black-backed Gull are both large gulls, but they differ significantly in size and plumage. The Great Black-backed Gull is notably larger and has a striking black back, while the Caspian Gull is smaller with a paler grey back. These differences are most apparent when the birds are seen side by side.

Identification tips

1. Size: Look for the larger size of the Great Black-backed Gull. 2. Back Color: Note the black back of the Great Black-backed Gull versus the grey back of the Caspian Gull. 3. Location: Consider the habitat; Great Black-backed Gulls are more coastal. 4. Behavior: Observe interactions; Great Black-backed Gulls are more dominant.

Size

The Great Black-backed Gull is the largest gull in the world, significantly larger than the Caspian Gull.

Plumage

The Great Black-backed Gull has a dark black back and wings, contrasting sharply with its white head and underparts. The Caspian Gull has a paler grey back and wings, with a more uniform appearance.

Behaviour

Both species are opportunistic feeders, but the Great Black-backed Gull is more aggressive and dominant, often displacing other gulls from feeding sites.

Habitat

The Great Black-backed Gull is often found in coastal areas, islands, and offshore rocks, while the Caspian Gull is more commonly found inland near large lakes and rivers.

Voice

Vocalizations are not a primary distinguishing feature between these species.