Petrels and Shearwaters

Breeding in these seabirds occurs when an individual reaches sexual maturity, usually between three and seven years of age. After an elaborate courtship and mating, a single white egg is laid, usually in a burrow or crevice, although some of the larger members of this group lay eggs on bare ground. Adult birds show long term fidelity to their mate and to their nest site.

Incubation time varies from about 40 days in the smaller petrels to about 55 days or more in the larger species. Both sexes incubate and care for the chick, which is fed a regurgitated mixture of rich stomach oil and fishy remains. Chicks can store large deposits of fat between feedings, which may be at intervals from several days to a week.

Chicks take their first flight when they reach 46-100 days old. The young birds spend their first year at sea before returning to land to socialize and investigate future nesting sites. Petrels and shearwaters can live a relatively long life, reaching into the upper twenties.