Black-headed Gull

Overview

The Black-headed Gull is a small, slender-billed gull widespread across Europe and Asia, with small numbers regularly reported along the northeastern coasts of North America. Despite its name, the breeding-season hood is a rich chocolate-brown rather than true black, a detail visible at close range or in good light. It is a highly social species, often seen loafing in large mixed flocks with other small gulls at reservoirs, harbors, and plowed fields.

In flight the species shows a distinctive pale wedge along the leading edge of the outer wing, formed by whitened outer primaries, which contrasts with a narrow black trailing edge. This wing pattern, combined with its buoyant, tern-like flight, helps distinguish it from superficially similar small gulls.

Feather Identification

• Wing feathers: Outer primaries are largely white with a thin black tip and trailing edge, creating the pale wing wedge visible in flight; inner primaries and secondaries are pale gray.
• Size and shape: Flight feathers are proportionately slim and pointed, matching the bird's light, buoyant build; primaries are shorter and less elongated than in larger gulls.
• Mantle and covert feathers: Soft pale gray with faint white fringing when fresh, becoming plainer with wear.
• Body feathers: White below, with a faint pinkish or grayish bloom sometimes present on the breast in breeding condition; hood feathers are dark chocolate-brown, not jet black, and molt to leave only a small dusky ear-spot in the nonbreeding season.
• Compared to similar species: Bonaparte's Gull shows a very similar white wing wedge but is smaller with a thinner black (not red) bill base and blacker hood; Little Gull shows dark, not white, underwings.

Plumage Details

Breeding adults show a dark chocolate-brown hood extending down the nape, a thin dark red bill, and red legs. In the nonbreeding season the hood is lost, leaving a white head marked with a small dark spot behind the eye and a smudge on the crown. Juveniles show variable brown mottling on the back and wing coverts, with a black band near the tip of the tail, and gradually acquire gray upperparts through their first year. First-winter birds retain a dark trailing edge to the wing and some brown coverts before completing their transition to adult-like plumage by the second year. The prebasic molt after breeding is protracted, with head feathers replaced gradually so that partially hooded individuals are commonly seen in late summer.

Habitat & Range

Black-headed Gulls breed colonially across temperate and subarctic Eurasia, from the British Isles to Kamchatka, nesting on marshes, islands, and lake margins. They are highly adaptable outside the breeding season, frequenting coastal estuaries, harbors, sewage outflows, refuse sites, and inland farmland far from water. The species is migratory to partially resident, with northern populations moving south and west to milder coasts in winter. Small numbers appear annually along the Atlantic coast of North America, particularly in the northeast, generally mixing in with flocks of Bonaparte's Gulls.

Behavior & Field Notes

Black-headed Gulls are gregarious at all seasons, forming dense breeding colonies and large nonbreeding roosts and feeding flocks. They forage opportunistically, taking invertebrates from mudflats and plowed fields, fish near the water's surface, and scavenging around human activity, often following boats or tractors. Flight is light and buoyant, with quick, shallow wingbeats reminiscent of a tern. Nests are shallow scrapes on the ground in dense colonies, often on islands protected from mammalian predators. The voice is a harsh, grating "kwarr" or laughing chatter, given frequently at colonies and roosts. Observers should note the bright white wing wedge and hood color when separating this species from Bonaparte's Gull in areas where both occur.