Glaucous Gull vs Glaucous-winged Gull

In short

The Glaucous Gull and Glaucous-winged Gull are large, pale gulls often found in overlapping coastal habitats. The most reliable field mark is the primary wingtip color: Glaucous Gulls have white wingtips, while Glaucous-winged Gulls have gray wingtips. Both species have similar overall structure, but subtle differences in plumage and behavior can aid identification.

Identification tips

• Check wingtip color: Glaucous Gulls have white wingtips; Glaucous-winged Gulls have gray wingtips.
• Consider size and bulk: Glaucous Gulls are slightly larger and bulkier.
• Observe habitat: Glaucous Gulls are more likely in Arctic regions; Glaucous-winged Gulls are coastal along the Pacific.
• Note plumage tone: Glaucous Gulls are paler overall compared to the slightly darker Glaucous-winged Gulls.

Size

Both species are large gulls, but the Glaucous Gull is slightly larger and bulkier than the Glaucous-winged Gull.

Plumage

Glaucous Gulls have white wingtips and a paler overall appearance, while Glaucous-winged Gulls have gray wingtips that match their mantle and upperwing color. Both have pale gray mantles, but the Glaucous-winged Gull's plumage is generally darker.

Behaviour

Both species are generalist feeders and can be seen scavenging or foraging along coastlines. Their behaviors are similar, often seen in mixed flocks with other gulls.

Habitat

Glaucous Gulls are more likely found in Arctic and sub-Arctic regions, often nesting on tundra and cliffs. Glaucous-winged Gulls are more coastal, frequenting the Pacific coast of North America.

Voice

Vocalizations are similar and not a reliable field mark for distinguishing these species.