Leucophaeus modestus
The Grey Gull (*Leucophaeus modestus*), locally known as the Garuma, is a distinctive medium-sized gull of the Pacific coast of South America, renowned for its remarkably pale, "smoky grey" plumage contrasting with dark primaries, a dark bill, and dark legs. Adults typically measure 45-50 cm in length with a wingspan of 110-120 cm, weighing between 360-480 grams. Its overall light grey body, white head (often streaked grayish in non-breeding plumage), and striking dark outer wingtips make it ...
This species exhibits a dual habitat preference, breeding exclusively on barren, hyper-arid inland desert plains and sand dunes, often far from water. During non-breeding periods and for daily foraging, it relies entirely on productive coastal marine environments, particularly cold-water upwellin...
Primarily piscivorous, the Grey Gull feeds almost exclusively on small pelagic fish, such as anchovies and sardines, and squid, often foraging nocturnally. It occasionally supplements its diet with marine invertebrates and scavenged items along the coastline.
The Grey Gull exhibits remarkable behavioral adaptations, most notably its predominantly nocturnal foraging patterns; it actively hunts fish and squid during moonlit nights, a trait unique among gulls and believed to minimize kleptoparasitism from other coastal birds. During the day, non-breeding...
The Grey Gull's breeding range is highly restricted to the hyper-arid coastal deserts of northern Chile and southern Peru, primarily within the Atacama Desert. Specific breeding colonies are found several kilometers inland from the Pacific coast, often in elevated, flat gravel plains. Following t...
Least Concern
- The Grey Gull is the only gull species globally known to breed exclusively in hyper-arid inland deserts, often more than 100 kilometers from the sea. - Adults undertake daily round trips of up to 200 kilometers between their desert breeding colonies and coastal feeding grounds to provision thei...