Goéland de Hemprich vs Goéland à iris blanc

The most reliable field mark to distinguish between the Sooty Gull and the White-eyed Gull is the eye color: the White-eyed Gull has a distinctive white eye ring, while the Sooty Gull does not. Both species are similar in size and structure, making eye color a crucial feature for identification.

Focus on the eye color: the White-eyed Gull has a white eye ring, while the Sooty Gull lacks this feature. This is the most reliable way to differentiate between the two species in the field.

Both species have similar plumage tones, but the White-eyed Gull's white eye ring is a key distinguishing feature.