Gray Gull Leucophaeus modestus Scientific name definitions

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

Diet and Foraging


Microhabitat for Foraging

Gray Gull forages actively at sea and on the beach; at sea, it feeds on zooplankton swarms and shoals of fish (32). Occasionally, it forages on fish escaping from other animals, like South American Sea Lions (Otaria flavescens; 32).

Food Capture and Consumption

Feeds much like sandpipers in the wave-washed littoral zone, taking mole crabs from 1 hour before low tide to 2 hours after. It surface-plunges for fish and nereid worms, scavenges in harbors, and follows fishing boats (33).

Gray Gull has a duplex retina, with a high number of rods, allowing them to see at night (34). It also adapts to the dark faster than other nocturnal gulls, such as the Ring-billed Gull (Larus delawarensis) (34). This might allow them to feed at night, and move to their colonies in the middle of the Atacama Desert.


Major Food Items

Feeds mainly and sometimes exclusively on mole crabs (Emerita analoga). It also feeds on fish (especially on Peruvian Anchovy [Engraulis ringens] and Sardines [Clupeidae]), nereid worms, and offal. Chicks are primarily fed fish, with adults making only one feeding trip per day to the desert areas in which it breeds. In an extralimital record in Mexico, it was recorded feeding on ray carcasses tossed away by people (Montejo and McAndrews, eBird).

Food Selection and Storage

Nothing known.

Nutrition and Energetics

Nothing known.

Metabolism and Temperature Regulation

Nothing known.

Drinking, Pellet-Casting, and Defecation

Nothing known.

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