Western Gulls

The expanse of concrete straight ahead, once an army parade ground and later a playground for the children of federal prison guards, is now a nesting ground for Alcatraz's vast colony of western gulls. Each winter, up to 1,100 pairs of western gulls return to breed and raise their young. Around February, the territorial, lifelong partners arrive on the island ready to fight, if necessary, for the same nesting spots they have had year after year. Using bits of vegetation and man-made debris, they build circular nests on the concrete. In April and May, for approximately 28 days, they incubate their eggs. In June, 2,000 to 3,000 chicks hatch and raise their voices, creating a screeching racket that continues over the parade ground through July and August.

San Francisco, California · United States