Common Gull vs Caspian Gull

In short

The Common Gull (Larus canus) and Caspian Gull (Larus cachinnans) can be differentiated by size, bill shape, and plumage details. Common Gulls are generally smaller with a more delicate bill, while Caspian Gulls are larger with a heavier bill. Pay attention to the mantle color and primary markings for more precise identification.

Identification tips

1. Size and Structure: Common Gull is smaller with a more delicate bill compared to the larger, heavier-billed Caspian Gull. 2. Mantle Color: Common Gull has a paler gray mantle, while Caspian Gull's mantle is slightly darker. 3. Primary Markings: Look for the extent of black on the primaries; Common Gull often lacks the white spots seen in Caspian Gull. 4. Eye Color: Common Gull generally has darker eyes than Caspian Gull.

Size

Common Gull is medium-sized, smaller and lighter than the larger Caspian Gull.

Plumage

Common Gull has a medium to pale gray mantle, often paler than Caspian Gull. The Common Gull's primary coverts show black extending to near tips on P8-P9, usually lacking the white spot seen in Caspian Gull. Caspian Gulls often have more extensive white in the wing tips and a slightly darker mantle.