gaivota-de-cabeça-preta vs gaivota-de-bico-riscado

The Mediterranean Gull and the Ring-billed Gull can be distinguished by their bill and head markings. The Mediterranean Gull has a thicker, all-red bill and a distinctive black hood in breeding plumage, while the Ring-billed Gull features a thinner, yellow bill with a black ring near the tip and lacks a full hood.

Bill: Mediterranean Gull has a thick, all-red bill; Ring-billed Gull has a thinner, yellow bill with a black ring. Head: Mediterranean Gull shows a full black hood in breeding plumage; Ring-billed Gull has a white head with streaking. Underwing: Mediterranean Gull has a more uniform white underwing.

Both species are medium-sized gulls, but the Ring-billed Gull is generally slightly larger.

In breeding plumage, the Mediterranean Gull has a full black hood, whereas the Ring-billed Gull has a white head with only some streaking. The Mediterranean Gull also shows a more uniform white underwing compared to the Ring-billed Gull.