Andean gull

The Andean gull (Chroicocephalus serranus) is a type of bird that belongs to the family of gulls, terns, and skimmers. This bird lives in several countries in South America, including Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru.

Andean gulls are part of a larger group called Larinae, which includes many different kinds of gulls. These birds are well adapted to the high-altitude environments of the Andes mountains, where they can often be seen near lakes, rivers, and coastal areas.

Because of where they live and what they eat, Andean gulls play an important role in keeping their habitats healthy. They help control the numbers of small animals and insects, and they also serve as a sign of how well the environment is doing. People who study birds and nature find Andean gulls very interesting because of how they have learned to survive in such challenging places.

Taxonomy and systematics

The Andean gull was once placed in a group called Larus. But new studies showed this group was not correctly organized. So, groups like the American Ornithological Society, the International Ornithological Committee, and the Clements taxonomy moved the Andean gull and 11 other birds to a new group called Chroicocephalus. However, BirdLife International still keeps them in Larus. All these groups agree that the Andean gull is a unique species with no close relatives.

Description

The Andean gull is a large bird. It measures between 42 to 48 cm (17 to 19 in) long and weighs around 480 g (17 oz). Both male and female birds look the same.

During breeding season, adult Andean gulls have a shiny black hood with a white patch behind the eye. Their bodies are mostly white with a gray back and sometimes a pinkish color on the belly. The tail is white. The top of their wings is mostly gray with a pattern of white and black on the primaries. The underside of the wings is pale gray with a darker outer edge and large white patches on the three outer wing feathers. Their bills, legs, and feet are blackish-brown with a hint of red, and their eyes are brown.

Outside of breeding season, adult Andean gulls have a white head and darker legs. It takes two years for an Andean gull to look like a fully grown adult. In the first year, young birds have some black spots on their heads, a complex black and white pattern on their wings, and a black band near the end of their tails.

Distribution and habitat

The Andean gull lives in the Andes mountains. You can find them from southern Colombia through Ecuador, Peru, Bolivia, Chile, and Argentina.

Some of these birds move near the coast in Peru and northern Chile when it is colder, but we do not know where they come from.

During breeding season, Andean gulls like lakes, marshes, and fields in high areas called puna and páramo. They usually live between 3,000 and 5,300 meters above sea level, but sometimes they can be as low as 1,200 meters in the south. In the winter, you might see them at river mouths and sandy beaches along the coast.

Behavior

The Andean gull searches for food in many ways. In the mountains, it eats earthworms, insects, small fish, and sometimes eggs or young birds. During winter, it also looks for food near ski resorts. Near the coast, it eats fish scraps, fish, and small sea creatures. It walks, swims, and flies to find its meals.

Breeding time for the Andean gull is mostly in July and August. These birds usually build nests in small groups but sometimes nest alone. They lay their nests along riverbanks and on islands in rivers and lakes. Most nests have two or three eggs, but sometimes there is just one or up to four. Not much is known about how long the eggs take to hatch or how the parents care for the young.

The Andean gull makes several different sounds, including a nervous "yeeer" call and a rough "raggh-aggh-keeaagh" sound, along with other low, grating notes.

Status

The IUCN says the Andean gull is safe right now. We do not know exactly how many of these birds there are or if their numbers are changing. There are no big dangers to them that we know of. However, these birds might be at risk because they live in remote, high-altitude lakes that are seeing more farming and human activity.