Andean Gull

Overview

The Andean gull (Chroicocephalus serranus) is a large member of its genus, belonging to the subfamily Larinae within the family of gulls, terns, and skimmers. It is a species found primarily in South America, ranging from Colombia to Argentina.

Identification

• 42 to 48 cm long, weighing about 480 g, making it one of the larger members of its genus.
• Breeding adults feature a glossy black hood with a white crescent behind the eye, a mostly white body, a gray back, and a white tail.
• Wings display a gray upper surface with alternating white and black patterns on the primaries, while the underside is pale gray with large white 'mirrors' on the outermost primaries.
• Vocalisations include agitated, tremulous "yeeer" calls and hoarse, low raspy notes such as "raggh-aggh-keeaagh".

Habitat

Found year-round in the Andes from southwestern Colombia south to Chile and Argentina, specifically in the puna and páramo zones of the Altiplano at elevations between 3,000 and 5,300 m. During winter, individuals move to the coast, inhabiting river mouths and sand beaches from central Peru to northern Chile.

Diet

In mountainous areas, the bird feeds on earthworms, insects, amphibians, small fish, and occasionally the eggs and chicks of other waterbirds. Along the coast, its diet consists of offal, fish, and marine invertebrates, and it may also scavenge at ski resorts. It forages by walking, swimming, and flying to locate food.

Did you know?

The species has been recorded as a vagrant in Amazonian Peru and far southern Argentina, outside its typical high-altitude Andean range.