The Gray Gull is one of the most common species on the Pacific Coast influenced by the Humboldt Current. For years it was a mystery as to where this species bred. They were seen copulating on the coast, vocalizing and displaying, but no nests were found. Given the many thousands present on shore it was a paradox that no colonies had been discovered. It was not until the early 1970s that it was confirmed that this gull breeds deep in the absolute desert of northern Chile. It takes flat areas in the desert, where often no measurable rainfall exists in a year, a decade, or more. Lacking the basic element of life, water, these breeding areas are surprisingly safe as there are few to no predators there. As the gulls are highly mobile they can commute from the inland colonies to the sea daily and provide food to the chicks. It is thought that the gray plumage coloration is an adaptation to life in hot, sunny places, as melanin keeps feathers from becoming faded and weakened by light, and that they may be able to use the dark plumage to radiate heat more efficiently than translucent white plumage. Most other desert nesting gulls, even if unrelated, are gray. The Gray Gull is vocally quite similar to the Laughing Gull (Leucophaeus atricilla) and is likely closely related to it.