Adult Description
- Small gull.
- Back and wings pale gray with white wingtips.
- Underside of wings blackish.
- Underparts white.
- Head black during breeding.
- Dark spot behind eyes and on cap in winter.
Immature Description
Juvenile Plumage: Much blackish on head, neck, and back, a black bar across the wing, and a black tail tip.
First Winter (Basic I) Plumage: similar to nonbreeding adult, but with brownish black bar across the base of the wing, much black in the outer wing, and a black band across the tip of the tail.
First Summer (Alternate I) Plumage: Like first winter, but with full or partial hood. Dark on back fades with wear. Center of tail tip often white.
Second Winter (Basic II) Plumage: Like adult, but variable black markings on upper wingtip, and paler under wings.Relative Size

crow-sizedMeasurements
- Both Sexes
- Length: 11.4-11.8 in (29-30 cm)
- Weight: 3.5-5.3 oz (100-150 g)
- Wingspan: 24.0 in (61 cm)