(Part of the) common name of many species in the families Procellariidae (typical petrels and shearwaters), Hydrobatidae (storm-petrels) and Pelecanoididae (diving petrels) and in the plural the general name for the whole order of Procellariiformes. The order of petrels is a distinct group of seabirds characterised by their peculiar musky smell, thick plumage, webbed feet, and deeply grooved, markedly hooked bills with prolonged tubular nostrils (related to their great smelling capacities and excretion of excess salt by the nasal gland). They are all totally marine (and very helpless on the land), usually feeding on the larger zooplankton, cephalopods (cuttlefish, squids and octopods) or fish in the open ocean and they have a long breeding cycle and life expectation together with a low reproductive rate. A well-known example is the albatross.

Alternative forms for petrels : Hydrobates, Oceanites, Oceanodroma, petrel.