Small cephalopods, such as octopus and squid, make up the bulk of this species’ diet, although Murphy’s petrel also feeds on fish and crustaceans (3) (12). Its short, stout bill, equipped with a powerful hook and sharp cutting edge, is used for gripping and cutting up small squid and fish (13). This species also opportunistically scavenges on larger dead animals that are too big for the petrels to kill or swallow intact, feeding first on the easily-removed eyes (12).
Murphy’s petrel nests on the ground in small colonies, generally in shallow scrapes under trees, shrubs or low vegetation, or in cliff cavities (3) (11). Birds begin the breeding process in late March, and a single, large white egg is laid around late May to mid July (3). Incubation of the egg is shared alternately by both adults (13). The egg hatches in late July to August, and the juvenile Murphy’s petrel remains in the nest for around 100 days (3). The chicks are fed by the adults approximately twice every ten days. Studies suggest that although Murphy’s petrel seems to feed relatively infrequently, the chicks of this species probably receive larger meals than the chicks of other similar petrel species (12).
Outside of the breeding season, Murphy’s petrel migrates to the north and east Pacific, where it spends much of its time at sea. Non-breeding birds may remain in this region throughout the year, being recorded off California between April and July, Alaska in July, and Hawaii in September to November. Evidence suggests that this species probably migrates through the region in an anticlockwise direction (11).