Procellariidae

Procellariidae
Name	Procellariidae
Taxon	Procellariidae
Authority	Leach, 1820
Subdivision ranks	Genera
Subdivision	See text.

Procellariidae. This family of seabirds, commonly known as petrels, shearwaters, and fulmars, constitutes a major group within the order Procellariiformes. They are pelagic, highly adapted for life on the open ocean, and are found from the Arctic to the Antarctic waters. Known for their exceptional olfactory capabilities and long-distance migrations, they are a key component of marine ecosystems worldwide.

Taxonomy and systematics

The family Procellariidae was formally described by the English zoologist William Elford Leach in 1820. It is one of four families within the order Procellariiformes, alongside Diomedeidae, Hydrobatidae, and Oceanitidae. Molecular phylogenetic studies, including those analyzing mitochondrial DNA, have helped clarify relationships within the family, leading to the recognition of several major groups. The family is divided into numerous genera, including Pterodroma (gadfly petrels), Calonectris and Ardenna (shearwaters), Fulmarus (fulmars), and Procellaria. The taxonomy of some groups, such as the Pterodroma petrels, remains complex and is subject to revision with ongoing research, including work by institutions like the British Ornithologists' Union.

Description and morphology

Procellariids exhibit a range of sizes, from the small diving petrel-like species to the large giant petrels, which rival some albatrosses in wingspan. They possess characteristic tubular nostrils, a feature shared with other Procellariiformes, which house their highly developed olfactory glands. Their wings are long and narrow, an adaptation for dynamic soaring over ocean waves, a flight technique mastered by birds like the sooty shearwater. The plumage is typically shades of black, white, gray, and brown, often with darker upperparts and lighter underparts. Their legs are set far back on the body, making them awkward on land but powerful swimmers.

Distribution and habitat

Members of this family have a truly global distribution across all the world's oceans. Different species occupy distinct pelagic realms, from the cold waters of the Southern Ocean, home to the Antarctic petrel and snow petrel, to the temperate and tropical seas. Key breeding sites are often remote, predator-free islands, such as those in the South Georgia, the Antipodes Islands, the Galápagos Islands, and the Aleutian Islands. Many species are highly migratory; for example, the short-tailed shearwater undertakes a remarkable trans-equatorial migration from breeding grounds in Tasmania to feeding areas in the North Pacific Ocean.

Behaviour and ecology

Procellariids are primarily planktivorous, piscivorous, or scavengers, feeding on krill, squid, small fish, and offal. Species like the northern fulmar are notorious scavengers around fishing vessels. They are colonial nesters, often returning to the same burrow or cliff ledge site annually. Courtship involves complex vocalizations and displays. A single egg is laid per breeding season, and both parents share in the long incubation and chick-rearing duties. Their highly developed sense of smell is crucial for locating food across vast ocean expanses and for finding their nesting burrows at night.

Relationship with humans

Historically, procellariids have been exploited by humans. On islands like Saint Helena and Tristan da Cunha, species such as the great shearwater were harvested for food, oil, and feathers. They feature in the maritime folklore of many cultures, including those of Polynesia and New Zealand, where the Māori people used the feathers of certain petrels. In modern times, some species have benefited from fisheries discards, while others suffer from bycatch in longline and gillnet fisheries, a significant threat documented by organizations like the International Union for Conservation of Nature.

Conservation

Conservation status varies widely among species. While some, like the northern fulmar, have expanded their ranges, many are threatened. The IUCN Red List classifies numerous species, such as the Balearic shearwater and the Magenta petrel, as Critically Endangered. Primary threats include invasive species like rats and cats at breeding colonies, plastic pollution, climate change affecting prey distribution, and fisheries bycatch. Conservation efforts led by groups like BirdLife International focus on island restoration, predator eradication, and advocating for bycatch mitigation measures under agreements like the Agreement on the Conservation of Albatrosses and Petrels.

Category:Procellariidae Category:Procellariiformes