Diving petrel

The diving petrels form a genus, Pelecanoides, of seabirds in the family Procellariidae. There are four very similar species of diving petrels, distinguished only by small differences in the coloration of their plumage, habitat, and bill construction. They are only found in the southern hemisphere. The diving petrels were formerly placed in their own family, the Pelecanoididae. Diving petrels are auk-like small petrels of the southern oceans. The resemblances with the auks are due to convergent evolution, since both families feed by pursuit diving, although some researchers have in the past suggested that the similarities are due to relatedness. Among the Procellariiformes the diving petrels are the family most adapted to life in the sea rather than flying over it, and are generally found closer inshore than other families in the order. The genus Pelecanoides was introduced in 1799 by the French naturalist Bernard Germain de Lacépède for the common diving petrel. The genus name combines the Ancient Greek pelekan meaning "pelican" and "-oidēs" meaning "resembling". The diving petrels were formerly placed in their own family, Pelecanoididae. When genetic studies found that they were embedded within the family Procellariidae, the family Pelecanoididae were merged into Procellariidae. Four species are usually recognised: A fifth species, the Whenua Hou diving-petrel (Pelecanoides whenuahouensis), is sometimes recognised. It was first described in 2018 and is found around Codfish Island / Whenua Hou, New Zealand. In the bird list maintained by Frank Gill, Pamela Rasmussen and David Donsker on behalf of the International Ornithological Committee the Whenua Hou diving-petrel is treated as a subspecies of the South Georgia diving petrel. The evolution and systematics of these birds is not well researched. Several populations were described as distinct species and while most of them are only subspecies, some may indeed be distinct. The prehistoric fossil record was long limited to very fragmentary remains described as P.