Gray Gull Leucophaeus modestus Scientific name definitions

Fernando Medrano, Ignacio Escobar Gutiérrez, and Rodrigo Silva
Version: 2.0 — Published December 23, 2022



Breeding Sites

The breeding sites of Gray Gull remain mostly undiscovered. Most of what is known is related to their colonies, but there are also scattered nests distributed through the desert (see Breeding). Known sites are distributed as follows:


In Peru, there is one record of a failed breeding attempt on Independencia Island (17). An identified colony in El Cangrejal, on the coast of Ica (18) no longer exists (C. Zavalaga, personal communication). However, it is highly probable that there are several breeding colonies in the Peruvian desert. There are inland records of individual Gray Gulls up to 40 km from the coast in the Valle de Locumba, near Tacna (J. Vizcarra, personal communication).


In Chile, few breeding colonies have been discovered, although there are many mature individuals along the coast.

In the regions of Arica and Parinacota there are no known breeding colonies (R. Peredo, personal communication) even though there are records of several hundred individuals flying over the desert in Pampa Chaca and Pampa Camarones (19). A similar situation has also been observed in the region of Tarapaca, and only a few scattered nests have been recorded in Tente en el aire. However, dozens of birds have been recorded flying over the salt-flats of Pampa Quiuña (Manríquez et al., eBird), Pintados, and Llamara during the night, suggesting larger colonies have yet to be discovered (19).

In the region of Antofagasta, there have been several known breeding colonies. Aguilar-Pulido et al. (20) surveyed the historical breeding colonies, finding active colonies in 2021, which included Cerro Posada (750 breeding pairs), El Tigre 2 (2,000 breeding pairs), Pampa Barrancas (80 breeding pairs), Colupo D (10,000 individuals), Pampa Lidia (91 breeding pairs), and Los Vientos (63 breeding pairs). All the other known colonies were inactive, including Cerro Chanchito, El Pedregal, Central, El Tigre 1, Lealtad, San Martin, Tigre, Colupo A, Colupo B, Colupo C, Quimurku, Sierra Valenzuela, Ercilla, Llanos, Cerro Negro, Domeyko, Cerro Plomo, Cerro Trapecio, and the coastal Playa Brava and Playa Grande colonies (21, 22, 23, 24, 22, 25, 20).

The region of Atacama contains only scattered nests in the Pampa del Indio Muerto (Caballero, eBird 1, 2), near the only known breeding colony for Ringed Storm-Petrel (Hydrobates hornbyi).

Finally, there is an old record of a breeding attempt far from the Atacama Desert, in the Maule region of Chile. In this attempt, a dozen pairs had nests in the wetland of Reloca, but all of them were unsuccessful. There are no current recordings of this behavior in the area (M. A. Vukasovic, personal communication).

Distance from the Coast

Most of the colonies from the Antofagasta region are either 20–40 km (45% of the colonies) or 80–100 km (30% of the colonies) from the coast (20).

Non-breeding Distribution

In the non-breeding season, Gray Gull moves both north and south, reaching from Ecuador in the north to the Arauco Gulf in Chile in the south (26), and occasionally reaching Chiloé (19). During the non-breeding season, it is mostly coastal but has been recorded on inland lakes, especially in the Los Lagos region in Chile (e.g. Troncoso, eBird; Gamberini, eBird).

Extralimital Records

Gray Gull has occasionally been documented as a vagrant far from its typical range. A record in Louisiana in 1987, which would represent the northernmost record, has been a subject of debate, since a melanistic Laughing Gull (Leucophaeus atricilla) cannot be ruled out (S. Finnegan, flickr). In 2009, one was recorded in Celestún, Mexico (Scott, eBird; Montejo and McAndrews, eBird); another was recorded in 2021 near Campeche (Reyes, eBird). In 2015, Gray Gull was recorded in Tolar Grande, Argentina (27). In 2019, it was reported in Ilha Comprimida, in Brazil (28). It has also been recorded from the Altiplano, far from its regular range, in Toconao (Páez, eBird) and San Pedro de Atacama (Rivas and Heindl, eBird).

Historical Changes to the Distribution

Historically, the Cerro Negro Norte had as many as 50 breeding pairs, Cerro Plomo had approximately 12,000 breeding pairs, and scattered nests were recorded in Sierra Valenzuela and Cerro Negro. Furthermore, there are other abandoned breeding colonies in Colupo, Lealtad, El Tigre, El Pedregal, Antucoya, Quimurku, and Sierra Valenzuela (20). In 2017 the breeding colony of Cerro Plomo was not occupied (19). Surprisingly, in 2014–2015 two new breeding colonies were established next to the sea in Playa Grande (40 breeding pairs) and Playa Brava (150 breeding pairs) (17). In 2017, the breeding colony of Playa Brava increased its size to 1,500 breeding pairs (19), but these colonies do not exist any more. Later, some nest were described from Cerro Trapecio (29). The southernmost known large colony is near Quillagua, in Cerro Chanchito, where there is a population of 30,000 breeding pairs (17, 30). Furthermore, in this region, dozens of birds have been recorded flying over Sierra Vicuña Mackenna (Contreras, eBird), Oficina Yugoslavia (Gallardo, eBird), and Quebrada San Ramón (Manríquez et al., eBird). Also, there are scattered nests near Cerro Paranal.

Distribution of the Gray Gull - Range Map
  • Year-round
  • Migration
  • Breeding
  • Non-Breeding
Distribution of the Gray Gull

Recommended Citation

Medrano, F., I. Escobar Gutiérrez, and R. Silva (2022). Gray Gull (Leucophaeus modestus), version 2.0. In Birds of the World (S. M. Billerman, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.grygul.02