Austral storm petrel

Austral storm petrels, or southern storm petrels, are seabirds in the family Oceanitidae, part of the order Procellariiformes. These smallest of seabirds feed on planktonic crustaceans and small fish picked from the surface, typically while hovering. Their flight is fluttering and sometimes bat-like. Historically, they were grouped together with the Hydrobatidae in an encompassing storm petrel group, though genetic testing found them to be distantly related, and so they were split.

Austral storm petrels have a cosmopolitan distribution, being found in all oceans, although only Wilson's storm petrel and white-faced storm petrel are found in the Northern Hemisphere. They are almost all strictly pelagic, coming to land only to breed. Little is known of the behaviour and distribution at sea for many species, where they can be hard to find and harder to identify. They are colonial nesters, displaying strong philopatry to their natal colonies and nesting sites. Most species nest in crevices or burrows, and all but one species attend their breeding colonies nocturnally. Pairs form long-term monogamous bonds and share incubation and chick-feeding duties. Like many species of seabirds, nesting is highly protracted with incubation taking up to 50 days and fledging another 70 days after that.

The family contains ten species assigned to five different genera. Several species are threatened by human activities. The New Zealand storm petrel was presumed extinct until rediscovered in 2003. The principal threats to storm petrels are introduced species, particularly mammals, in their breeding colonies; many storm petrels habitually nest on isolated mammal-free offshore islands and are unable to cope with predators such as rats and feral cats.