Single-brooded, and both parents incubate. Incubation period 23-27 days. Begins breeding in 3d yr. This colony was destroyed when mainland predators crossed to Negit Island on a landbridge that emerged with receding lake waters. Diversion of feeder streams from Mono Lake into the Los Angeles Aqueduct has caused the lake to lose about half its volume since the early 1940s.
Life history notes on the California gull.
Great Basin Nat. Bent, A. C. 1921. Life histories of North American gulls and terns. Cogswell, H. L. 1977. Water birds of California.