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The
family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Procellariidae is a group of
seabird Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same envir ...
s that comprises the fulmarine petrels, the
gadfly petrel The gadfly petrels or ''Pterodroma'' are a genus of about 35 species of petrels, part of the seabird order Procellariiformes. The gadfly petrels are named for their speedy weaving flight, as if evading gadflies ( horseflies). The flight action is ...
s, the diving petrels, the prions, and the shearwaters. This family is part of the bird
order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...
Procellariiformes Procellariiformes is an order of seabirds that comprises four families: the albatrosses, the petrels and shearwaters, and two families of storm petrels. Formerly called Tubinares and still called tubenoses in English, procellariiforms are oft ...
(or tubenoses), which also includes the
albatross Albatrosses, of the biological family Diomedeidae, are large seabirds related to the procellariids, storm petrels, and diving petrels in the order Procellariiformes (the tubenoses). They range widely in the Southern Ocean and the North Pac ...
es and the
storm petrel Storm-petrel may refer to one of two bird families, both in the order Procellariiformes, once treated as the same family. The two families are: * Northern storm petrels (''Hydrobatidae'') are found in the Northern Hemisphere, although some speci ...
s. The procellariids are the most numerous family of tubenoses, and the most diverse. They range in size from the
giant petrel Giant petrels form a genus, ''Macronectes'', from the family Procellariidae, which consists of two species. They are the largest birds of this family. Both species are restricted to the Southern Hemisphere, and though their distributions overla ...
s with a wingspan of around , that are almost as large as the albatrosses, to the diving petrels with a wingspan of around that are similar in size to the
little auk The little auk or dovekie (''Alle alle'') is a small auk, the only member of the genus ''Alle''. ''Alle'' is the Sami name of the long-tailed duck; it is onomatopoeic and imitates the call of the drake duck. Linnaeus was not particularly f ...
s or dovekies in the family
Alcidae An auk or alcid is a bird of the family Alcidae in the order Charadriiformes. The alcid family includes the murres, guillemots, auklets, puffins, and murrelets. The word "auk" is derived from Icelandic ''álka'', from Old Norse ''alka'' (a ...
. Male and female birds are identical in appearance. The plumage color is generally dull, with blacks, whites, browns and grays. The birds feed on fish,
squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fittin ...
and
crustacea Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group c ...
, with many also taking fisheries discards and
carrion Carrion () is the decaying flesh of dead animals, including human flesh. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...
. Whilst agile swimmers and excellent in water, petrels have weak legs and can only shuffle on land, with the giant petrels of the genus Macronectes being the only two species that can properly walk. All species are accomplished long-distance foragers, and many undertake long trans-equatorial migrations. They are colonial breeders, exhibiting long-term mate fidelity and site philopatry. In all species, a single white egg is laid each breeding season. The parents take it in turns to incubate the egg and to forage for food. The feeding area can be at a great distance from the nest site. The incubation times and chick-rearing periods are exceptionally long compared to other birds. Many procellariids have breeding populations of over several million pairs; others number fewer than 200 birds. Humans have traditionally exploited several species of
fulmar The fulmars are tubenosed seabirds of the family Procellariidae. The family consists of two extant species and two extinct fossil species from the Miocene. Fulmars superficially resemble gulls, but are readily distinguished by their flight on ...
and shearwater (known as muttonbirds) for food, fuel, and bait, a practice that continues in a controlled fashion today. Several species are threatened by
introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...
attacking adults and chicks in breeding colonies and by long-line fisheries.


Taxonomy and evolution

The
family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Procellariidae was introduced (as Procellaridæ) by the English zoologist
William Elford Leach William Elford Leach FRS (2 February 1791 – 25 August 1836) was an English zoologist and marine biologist. Life and work Elford Leach was born at Hoe Gate, Plymouth, the son of an attorney. At the age of twelve he began a medical appre ...
in a guide to the contents of the
British Museum The British Museum is a public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is among the largest and most comprehensive in existence. It docum ...
published in 1820. The name is derived from the
type genus In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal ...
''
Procellaria Procellaria is a genus of Southern Ocean long-winged seabirds related to prions, and within the order Procellariiformes. The black petrel (''Procellaria parkinsoni'') ranges in the Pacific Ocean, and as far north as Central America. The specta ...
'' which in turn is derived from the
Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through ...
word ''procella'' meaning "storm" or "gale". The type genus was named in 1758 by the Swedish naturalist
Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, ...
in the tenth edition of his ''
Systema Naturae ' (originally in Latin written ' with the ligature æ) is one of the major works of the Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the system, now known as binomial ...
''. Procellariidae is one of families that make up the
order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...
Procellariiformes Procellariiformes is an order of seabirds that comprises four families: the albatrosses, the petrels and shearwaters, and two families of storm petrels. Formerly called Tubinares and still called tubenoses in English, procellariiforms are oft ...
. Before the introduction of
molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
s, the traditional arrangement was to divide the Procellariiformes into a set of four families: Diomedeidae containing the albatrosses, Hydrobatidae containing all the storm petrels, Pelecanoididae containing the diving petrels and Procellariidae containing the petrels, shearwaters and fulmars. The family Hydrobatidae was further divided into two subfamilies, the northern storm petrels in Hydrobatinae and the southern or austral storm petrels in Oceanitinae. A 1998 analysis of mitochondrial cytochrome ''b'' sequences found there was deep genetic divergence between the two subfamilies. Subsequent large-scale multigene studies found that the two subfamilies were not
sister taxa In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...
. The storm petrels were therefore split into two families: Hydrobatidae containing the northern storm petrels and Oceanitidae, containing the southern storm petrels. The multigene genetic studies found that the diving petrels in the family Pelecanoididae were nested within the family Procellariidae. As a result, the diving petrels was merged into Procellariidae. The molecular evidence suggests that the albatrosses were the first to diverge from the ancestral stock, and the austral storm petrels next, with the procellariids and northern storm petrels splitting most recently. Within the procellariid family, a genetic analysis based on the cytochrome ''b'' gene published in 2004 indicated that the genus ''Puffinus'' contained two distinct
clades A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English te ...
and was
polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of conver ...
. The genus was therefore split and a group of species moved into the resurrected genus '' Ardenna''. The other genera within the family were found to be
monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...
but the relationships between the genera remained unclear. This changed when a multigene genetic study published in 2021 provided a genus-level phylogeny of the family. There are 99
species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...
of procellariid in 16
genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
. The family has usually been broken up into four fairly distinct groups; the fulmarine petrels, the
gadfly petrel The gadfly petrels or ''Pterodroma'' are a genus of about 35 species of petrels, part of the seabird order Procellariiformes. The gadfly petrels are named for their speedy weaving flight, as if evading gadflies ( horseflies). The flight action is ...
s, the prions, and the shearwaters. With the inclusion of the diving petrels there are now five main groups. * The fulmarine petrels include the largest procellariids, the
giant petrel Giant petrels form a genus, ''Macronectes'', from the family Procellariidae, which consists of two species. They are the largest birds of this family. Both species are restricted to the Southern Hemisphere, and though their distributions overla ...
s, as well as the two
fulmar The fulmars are tubenosed seabirds of the family Procellariidae. The family consists of two extant species and two extinct fossil species from the Miocene. Fulmars superficially resemble gulls, but are readily distinguished by their flight on ...
species, the
snow petrel The snow petrel (''Pagodroma nivea'') is the only member of the genus ''Pagodroma.'' It is one of only three birds that has been seen at the Geographic South Pole, along with the Antarctic petrel and the south polar skua, which have the most s ...
, the
Antarctic petrel The Antarctic petrel (''Thalassoica antarctica'') is a boldly marked dark brown and white petrel, found in Antarctica, most commonly in the Ross and Weddell Seas. They eat Antarctic krill, fish, and small squid. They feed while swimming but c ...
, and the Cape petrel. The fulmarine petrels are a diverse group with differing habits and appearances, but are linked morphologically by their
skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...
features, particularly the long prominent nasal tubes. *The four diving petrels are the smallest procellariids with lengths of around and wingspans of . They are compact birds with short wings that are adapted for use under water. They have a characteristic whirring flight and dive into the water without settling. They probably remain all year in the seas near their breeding sites. * The gadfly petrels, so named due to their helter-skelter flight, are the 37 species in the
genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
'' Pterodroma''. The species vary from small to medium sizes, in length, and are long winged with short hooked bills. They are most closely related to
Kerguelen petrel The Kerguelen petrel (''Aphrodroma brevirostris'') is a small (36 cm long) slate-grey seabird in the family Procellariidae. It is the only species placed in the genus ''Aphrodroma''. It is a pelagic, circumpolar seabird of the Southern Oc ...
which is placed in its own genus ''Aphrodroma''. * The prions comprise six species of true prion in the genus '' Pachyptila'' and the closely related blue petrel. Often known in the past as whalebirds, three species have large bills filled with lamellae that they use to filter
plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a cruc ...
somewhat as
baleen whale Baleen whales ( systematic name Mysticeti), also known as whalebone whales, are a parvorder of carnivorous marine mammals of the infraorder Cetacea ( whales, dolphins and porpoises) which use keratinaceous baleen plates (or "whalebone") in t ...
s do, though the old name derives from their association with whales, not their bills (though "prions" does, deriving from
Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic pe ...
for " saw"). They are small procellariids, in length, with a prominent dark M-shaped mark across the upperwing of their grey plumage. All are restricted to the southern hemisphere. * The shearwaters are adapted for diving after prey instead of foraging on the ocean's surface; several species have been recorded diving deeper than . They are known for the long trans-equatorial migrations undertaken by many species. The shearwaters include the 20 or so species of the genus '' Puffinus'', seven species in the genus '' Ardenna'', as well as the five large ''
Procellaria Procellaria is a genus of Southern Ocean long-winged seabirds related to prions, and within the order Procellariiformes. The black petrel (''Procellaria parkinsoni'') ranges in the Pacific Ocean, and as far north as Central America. The specta ...
'' species and the four '' Calonectris'' species. While all these four genera are often known collectively as shearwaters, the ''Procellaria'' are called petrels in their common names.


Morphology and flight

The procellariids are small- to medium-sized seabirds. The largest, the
southern giant petrel The southern giant petrel (''Macronectes giganteus''), also known as the Antarctic giant petrel, giant fulmar, stinker, and stinkpot, is a large seabird of the southern oceans. Its distribution overlaps broadly with the similar northern giant pet ...
with a wingspan of , is almost as large as albatrosses; the smallest, the diving petrels have a wingspan of and are similar in size to
little auk The little auk or dovekie (''Alle alle'') is a small auk, the only member of the genus ''Alle''. ''Alle'' is the Sami name of the long-tailed duck; it is onomatopoeic and imitates the call of the drake duck. Linnaeus was not particularly f ...
s or dovekies in the family
Alcidae An auk or alcid is a bird of the family Alcidae in the order Charadriiformes. The alcid family includes the murres, guillemots, auklets, puffins, and murrelets. The word "auk" is derived from Icelandic ''álka'', from Old Norse ''alka'' (a ...
. There are no obvious differences between the sexes, although females tend to be slighter. Like all Procellariiformes, the procellariids have a characteristic tubular nasal passage used for olfaction. This ability to smell helps to locate patchily distributed prey at sea and may help locate nesting colonies. The
plumage Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...
of the procellariids is usually dull, with greys, bluish greys, blacks and browns being the usual colours, although some species have striking patterns such as the Cape petrel. The technique of
flight Flight or flying is the process by which an object moves through a space without contacting any planetary surface, either within an atmosphere (i.e. air flight or aviation) or through the vacuum of outer space (i.e. spaceflight). This can be a ...
among procellariids depends on foraging methods. Compared to an average bird, all procellariids have a high aspect ratio (meaning their wings are long and narrow) and a heavy wing loading. Therefore, they must maintain a high speed in order to remain in the air. Most procellariids use two techniques to do this, namely,
dynamic soaring Dynamic soaring is a flying technique used to gain energy by repeatedly crossing the boundary between air masses of different velocity. Such zones of wind gradient are generally found close to obstacles and close to the surface, so the technique is ...
and slope soaring. Dynamic soaring involves gliding across wave fronts, thus taking advantage of the vertical wind gradient and minimising the effort required to stay in the air. Slope soaring is more straightforward: the procellariid turns to the wind, gaining height, from where it can then glide back down to the sea. Most procellariids aid their flight by means of flap-glides, where bursts of flapping are followed by a period of gliding; the amount of flapping dependent on the strength of the wind and the choppiness of the water. Because of the high speeds required for flight, procellariids need to either run or face into a strong wind in order to take off. The giant petrels share with the albatrosses an adaptation known as a shoulder-lock: a sheet of
tendon A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...
that locks the wing when fully extended, allowing the wing to be kept up and out without any muscle effort. Gadfly petrels often feed on the wing, snapping prey without landing on the water. The flight of the smaller prions is similar to that of the
storm petrel Storm-petrel may refer to one of two bird families, both in the order Procellariiformes, once treated as the same family. The two families are: * Northern storm petrels (''Hydrobatidae'') are found in the Northern Hemisphere, although some speci ...
s, being highly erratic and involving weaving and even looping the loop. The wings of all species are long and stiff. In some species of shearwater the wings are used to power the birds underwater while diving for prey. Their heavier wing loadings, in comparison with surface-feeding procellariids, allow these shearwaters to achieve considerable depths (below in the case of the
short-tailed shearwater The short-tailed shearwater or slender-billed shearwater (''Ardenna tenuirostris''; formerly ''Puffinus tenuirostris''), also called yolla or moonbird, and commonly known as the muttonbird in Australia, is the most abundant seabird species in A ...
). Procellariids generally have weak legs that are set back, and many species move around on land by resting on the breast and pushing themselves forward, often with the help of their wings. The exceptions to this are the two species of giant petrel, which have strong legs used when they feed on land.


Distribution and migration

The procellariids are present in all the world's oceans and most of the seas. They are absent from the
Bay of Bengal The Bay of Bengal is the northeastern part of the Indian Ocean, bounded on the west and northwest by India, on the north by Bangladesh, and on the east by Myanmar and the Andaman and Nicobar Islands of India. Its southern limit is a line bet ...
and
Hudson Bay Hudson Bay ( crj, text=ᐐᓂᐯᒄ, translit=Wînipekw; crl, text=ᐐᓂᐹᒄ, translit=Wînipâkw; iu, text=ᑲᖏᖅᓱᐊᓗᒃ ᐃᓗᐊ, translit=Kangiqsualuk ilua or iu, text=ᑕᓯᐅᔭᕐᔪᐊᖅ, translit=Tasiujarjuaq; french: b ...
, but are present year round or seasonally in the rest. The seas north of
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...
are the centre of procellariid
biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic ('' genetic variability''), species ('' species diversity''), and ecosystem ('' ecosystem diversity'') ...
, with the most species. Among the groups, the fulmarine petrels have a mostly
polar Polar may refer to: Geography Polar may refer to: * Geographical pole, either of two fixed points on the surface of a rotating body or planet, at 90 degrees from the equator, based on the axis around which a body rotates *Polar climate, the cli ...
distribution, with most species living around
Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest cont ...
and one, the
northern fulmar The northern fulmar (''Fulmarus glacialis''), fulmar, or Arctic fulmar is a highly abundant seabird found primarily in subarctic regions of the North Atlantic and North Pacific oceans. There has been one confirmed sighting in the Southern Hem ...
ranging in the Northern
Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...
and
Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contine ...
Oceans. Of the four species of diving petrel, two are found along the coasts of South America, while the remaining two have circumpolar distributions in the Southern Ocean. The prions are restricted to the
Southern Ocean The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the World Ocean, generally taken to be south of 60° S latitude and encircling Antarctica. With a size of , it is regarded as the second-smal ...
, and the gadfly petrels are found mostly in the tropics with some temperate species. The shearwaters are the most widespread group and breed in most temperate and tropical seas. Many procellariids undertake long annual migrations in the non-breeding season. Southern species of shearwater such as the sooty shearwater and short-tailed shearwater, breeding on islands off
Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...
, New Zealand and
Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...
, undertake transequatorial migrations of millions of birds up to the waters off
Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U ...
and back each year during the austral winter.
Manx shearwater The Manx shearwater (''Puffinus puffinus'') is a medium-sized shearwater in the seabird family Procellariidae. The scientific name of this species records a name shift: Manx shearwaters were called Manks puffins in the 17th century. Puffin is a ...
s from the North Atlantic also undertake transequatorial migrations from Western Europe and North America to the waters off Brazil in the South Atlantic. The mechanisms of
navigation Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another.Bowditch, 2003:799. The field of navigation includes four general categories: land navigation ...
are poorly understood, but displacement experiments where individuals were removed from colonies and flown to far-flung release sites have shown that they are able to home in on their colonies with remarkable precision. A Manx shearwater released in
Boston Boston (), officially the City of Boston, is the state capital and most populous city of the Commonwealth of Massachusetts, as well as the cultural and financial center of the New England region of the United States. It is the 24th- mo ...
returned to its colony in
Skomer Skomer () or Skomer Island is an island off the coast of Pembrokeshire, in the community of Marloes and St Brides in west Wales. It is well known for its wildlife: around half the world's population of Manx shearwaters nest on the island, the A ...
,
Wales Wales ( cy, Cymru ) is a country that is part of the United Kingdom. It is bordered by England to the east, the Irish Sea to the north and west, the Celtic Sea to the south west and the Bristol Channel to the south. It had a population in ...
within 13 days, a distance of 5,150 kilometres (3,200 mi).


Behaviour


Food and feeding

The diet of the procellariids is the most diverse of all the Procellariiformes, as are the methods employed to obtain it. With the exception of the
giant petrel Giant petrels form a genus, ''Macronectes'', from the family Procellariidae, which consists of two species. They are the largest birds of this family. Both species are restricted to the Southern Hemisphere, and though their distributions overla ...
s, all procellariids are exclusively
marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military ...
, and the diet of all species is dominated by either fish,
squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fittin ...
,
crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapoda, decapods, ostracoda, seed shrimp, branchiopoda, branchiopods, argulidae, fish lice, krill, remipedes, isopoda, isopods, barnacles, copepods, ...
s and
carrion Carrion () is the decaying flesh of dead animals, including human flesh. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...
, or some combination thereof. The majority of species are surface feeders, obtaining food that has been pushed to the surface by other predators or currents, or have floated in death. Among the surface feeders some, principally the gadfly petrels, can obtain food by dipping from flight, while most of the rest feed while sitting on the water. These surface feeders are dependent on their prey being close to the surface, and for this reason procellariids are often found in association with other predators or oceanic convergences. Studies have shown strong associations between many different kinds of
seabird Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same envir ...
s, including wedge-tailed shearwaters, and
dolphin A dolphin is an aquatic mammal within the infraorder Cetacea. Dolphin species belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae (the b ...
s and
tuna A tuna is a saltwater fish that belongs to the tribe Thunnini, a subgrouping of the Scombridae (mackerel) family. The Thunnini comprise 15 species across five genera, the sizes of which vary greatly, ranging from the bullet tuna (max length: ...
, which push shoaling fish up towards the surface. The gadfly petrels and the Kerguelen petrel mainly feed at night. In so doing they can take advantage of the nocturnal migration of cephalopods and other food species towards the surface. The fulmarine petrels are generalists, which for the most part take many species of fish and crustacea. The giant petrels, uniquely for Procellariiformes, will feed on land, eating the carrion of other seabirds and
seals Seals may refer to: * Pinniped, a diverse group of semi-aquatic marine mammals, many of which are commonly called seals, particularly: ** Earless seal, or "true seal" ** Fur seal * Seal (emblem), a device to impress an emblem, used as a means of a ...
. They will also attack the chicks of other seabirds. The diet of the giant petrels varies according to sex, with the females taking more
krill Krill are small crustaceans of the order Euphausiacea, and are found in all the world's oceans. The name "krill" comes from the Norwegian word ', meaning "small fry of fish", which is also often attributed to species of fish. Krill are consi ...
and the males more carrion. All the fulmarine petrels readily feed on fisheries discards at sea, a habit that has been implicated in (but not proved to have caused) the expansion in range of the northern fulmar in the Atlantic. The three larger prion species have bills filled with lamellae, which act as filters to sift
zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...
from the water. Water is forced through the lamellae and small prey items are collected. This technique is often used in conjunction with a method known as hydroplaning where the bird dips its bill beneath the surface and propels itself forward with wings and feet as if walking on the water. The diving petrels and many of the shearwaters are proficient divers. While it has long been known that they regularly dive from the surface to pursue prey, using their wings for propulsion, the depth that they are able to dive to was not appreciated (or anticipated) until scientists began to deploy maximum-depth recorders on foraging birds. Studies of both long-distance migrants such as the sooty shearwater and more sedentary species such as the black-vented shearwater have shown maximum diving depths of and . Tropical shearwaters, such as the wedge-tailed shearwater and the
Audubon's shearwater Audubon's shearwater (''Puffinus lherminieri'') is a common tropical seabird in the petrel family. Sometimes known as the dusky-backed shearwater,Carboneras (1992) the specific epithet honours the French naturalist Félix Louis L'Herminier. Cer ...
, also dive in order to hunt, making the shearwaters the only tropical seabirds capable of exploiting that ecological niche (all other tropical seabirds feed close to the surface). Many other species of procellariid, from
white-chinned petrel The white-chinned petrel (''Procellaria aequinoctialis'') also known as the Cape hen and shoemaker, is a large shearwater in the family Procellariidae. It ranges around the Southern Ocean as far north as southern Australia, Peru and Namibia, and ...
s to slender-billed prions, dive to a couple of metres below the surface, though not as proficiently or as frequently as the shearwaters.


Breeding


Colonies

The procellariids are colonial, nesting for the most part on islands. These colonies vary in size from over a million birds to just a few pairs, and can be densely concentrated or widely spaced. At one extreme the greater shearwater nests in concentrations of one pair per square metre in three colonies of more than one million pairs, whereas the giant petrels nest in clumped but widely spaced territories that barely qualify as colonial. Colonies are usually located near the coast, but some species nest far inland and even at high altitudes.
Hutton's shearwater Hutton's shearwater (''Puffinus huttoni'') or the kaikōura tītī, is a medium-sized ocean-going seabird in the family Procellariidae. Its range is Australian and New Zealand waters, but it breeds only in mainland New Zealand. Its conservatio ...
(''Puffinus huttoni'') breeds in burrows on the sea-facing mountainside of the
Kaikōura Ranges The Kaikōura Ranges are two parallel ranges of mountains located in the northeast of the South Island of New Zealand. The two ranges are visible from a great distance, including from the southern coast of the North Island. Description Forme ...
on
South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...
, New Zealand. The colonies are above sea level at a distance of from the coast. Other exceptions are Barau's petrel (''Pterodroma baraui'') that breeds at on the island of
Réunion Réunion (; french: La Réunion, ; previously ''Île Bourbon''; rcf, label= Reunionese Creole, La Rényon) is an island in the Indian Ocean that is an overseas department and region of France. It is located approximately east of the island o ...
in the Indian Ocean, and the snow petrel (''Pagodroma nivea'') that breeds in Antarctica on mountain ledges up to from the open sea. Most seabirds are colonial, and the reasons for colonial behaviour are assumed to be similar, if incompletely understood by scientists. Procellariids for the most part have weak legs and are unable to easily take off, making them highly vulnerable to
mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur ...
ian predators. Most procellariid colonies are located on islands that have historically been free of mammals; for this reason some species cannot help but be colonial as they are limited to a few locations to breed. Even species that breed on continental Antarctica, such as the
Antarctic petrel The Antarctic petrel (''Thalassoica antarctica'') is a boldly marked dark brown and white petrel, found in Antarctica, most commonly in the Ross and Weddell Seas. They eat Antarctic krill, fish, and small squid. They feed while swimming but c ...
, are forced by habitat preference (snow-free north-facing rock) to breed in just a few locations. Most procellariids' nests are in burrows or on the surface on open ground, with a smaller number nesting under the cover of vegetation (such as in a forest). All the fulmarine petrels bar the snow petrel nest in the open, the snow petrel instead nesting inside natural crevices. Of the rest of the procellariids the majority nest in burrows or crevices, with a few tropical species nesting in the open. There are several reasons for these differences. The fulmarine petrels are probably precluded from burrowing by their large size (the crevice-nesting snow petrel is the smallest fulmarine petrel) and the high latitudes they breed in, where frozen ground is difficult to burrow into. The smaller size of the other species, and their lack of agility on land, mean that even on islands free from mammal predators they are still vulnerable to
skua The skuas are a group of predatory seabirds with seven species forming the genus ''Stercorarius'', the only genus in the family Stercorariidae. The three smaller skuas, the long-tailed skua, the Arctic skua, and the pomarine skua are calle ...
s,
gull Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century ...
s and other avian predators, something the aggressive
oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...
-spitting fulmars are not. The chicks of all species are vulnerable to predation, but the chicks of fulmarine petrels can defend themselves in a similar fashion to their parents. In the higher latitudes there are thermal advantages to burrow nesting, as the temperature is more stable than on the surface, and there is no wind-chill to contend with. The absence of skuas, gulls and other predatory birds on
tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...
islands is why some shearwaters and two species of gadfly petrel ( Kermadec petrel and the
herald petrel The Herald petrel (''Pterodroma heraldica'') is a species of seabird and a member of the gadfly petrels. Its range includes the south Pacific Ocean and Indian Ocean. Description The bird is in size, with an wingspan. It was formerly considere ...
) can nest in the open. This has the advantages of reducing competition with burrow nesters from other species and allowing open-ground nesters to nest on
coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and se ...
line islets without soil for burrowing. Procellariids that burrow in order to avoid predation almost always attend their colonies nocturnally in order to reduce predation as well. Procellariids display high levels of philopatry, exhibiting both natal philopatry and site fidelity. Natal philopatry, the tendency of a bird to breed close to where it hatched, is strong among all the Procellariiformes. The evidence for natal philopatry comes from several sources, not the least of which is the existence of several procellariid species that are endemic to a single island. The study of
mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial D ...
provides evidence of restricted
gene flow In population genetics, gene flow (also known as gene migration or geneflow and allele flow) is the transfer of genetic material from one population to another. If the rate of gene flow is high enough, then two populations will have equivalent a ...
between different colonies, and has been used to show philopatry in
fairy prion The fairy prion (''Pachyptila turtur'') is a small seabird with the standard prion plumage of blue-grey upperparts with a prominent dark "M" marking and white underneath. The sexes are alike. This is a small prion of the low subantarctic and sub ...
s.
Bird ringing Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight s ...
provides compelling evidence of philopatry; a study of
Cory's shearwater Cory's shearwater (''Calonectris borealis'') is a large shearwater in the seabird family Procellariidae. It breeds colonially of rocky islands in the eastern Atlantic. Outside the breeding season it ranges widely in the Atlantic. It was formerl ...
s nesting near
Corsica Corsica ( , Upper , Southern ; it, Corsica; ; french: Corse ; lij, Còrsega; sc, Còssiga) is an island in the Mediterranean Sea and one of the 18 regions of France. It is the fourth-largest island in the Mediterranean and lies southeast of ...
found that nine out of 61 male chicks that returned to breed at their natal colony actually bred in the burrow they were raised in. This tendency towards philopatry is stronger in some species than others, and several species readily prospect potential new colony sites and colonise them. It is hypothesised that there is a cost to dispersing to a new site, the chance of not finding a mate of the same species, that selects against it for rarer species, whereas there is probably an advantage to dispersal for species that have colony sites that change dramatically during periods of glacial advance or retreat. There are differences in the tendency to disperse based on sex, with females being more likely to breed away from the natal site.


Mate and site fidelity

Procellariids, as well as having strong natal philopatry, exhibit strong site fidelity, returning to the same nesting site, burrow or territory in sequential years. The figure varies for different species but is high for most species, an estimated 91% for Bulwer's petrels. The strength of this fidelity can also vary with sex; almost 85% of male
Cory's shearwater Cory's shearwater (''Calonectris borealis'') is a large shearwater in the seabird family Procellariidae. It breeds colonially of rocky islands in the eastern Atlantic. Outside the breeding season it ranges widely in the Atlantic. It was formerl ...
s return to the same burrow to breed the year after a successful breeding attempt, while the figure for females is around 76%. This tendency towards using the same site from year to year is matched by strong mate fidelity, with birds breeding with the same partner for many years; it has been suggested that the two are linked, with site fidelity acting as a means in which partnered birds could meet at the beginning of the breeding season. One pair of
northern fulmar The northern fulmar (''Fulmarus glacialis''), fulmar, or Arctic fulmar is a highly abundant seabird found primarily in subarctic regions of the North Atlantic and North Pacific oceans. There has been one confirmed sighting in the Southern Hem ...
s bred as a pair in the same site for 25 years. Like the
albatross Albatrosses, of the biological family Diomedeidae, are large seabirds related to the procellariids, storm petrels, and diving petrels in the order Procellariiformes (the tubenoses). They range widely in the Southern Ocean and the North Pac ...
es the procellariids take several years to reach sexual maturity, though due to the greater variety of sizes and lifestyles, the age of first breeding stretches from two or three years in the smaller species to 12 years in the larger ones. The procellariids lack the elaborate breeding dances of the albatrosses, in no small part due to the tendency of most of them to attend colonies at night and breed in burrows, where visual displays are useless. The fulmarine petrels, which nest on the surface and attend their colonies diurnally, do use a repertoire of stereotyped behaviours such as cackling, preening, head waving and nibbling, but for most species courtship interactions are limited to some billing (rubbing the two bills together) in the burrow and the vocalisations made by all species. The calls serve a number of functions: they are used territorially to protect burrows or territories and to call for mates. Each call type is unique to a particular species and indeed it is possible for procellariids to identify the sex of the bird calling. It may also be possible to assess the quality of potential mates; a study of blue petrels found a link between the
rhythm Rhythm (from Greek , ''rhythmos'', "any regular recurring motion, symmetry") generally means a " movement marked by the regulated succession of strong and weak elements, or of opposite or different conditions". This general meaning of regular re ...
and duration of calls and the body mass of the bird. The ability of an individual to recognise its mate has been demonstrated in several species.


Breeding season

Like most seabirds, the majority of procellariids breed once a year. There are exceptions; many individuals of the larger species, such as the
white-headed petrel The white-headed petrel (''Pterodroma lessonii''), also known as the white-headed fulmar, is a species of seabird in the petrel family, Procellariidae. It is about in length. White-headed petrels breed alone or in colonies in burrows dug among ...
, will skip a breeding season after successfully
fledging Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable ...
a chick, and some of the smaller species, such as the Christmas shearwaters, breed on a nine-month schedule. Among those that breed annually, there is considerable variation as to the timing; some species breed in a fixed season while others breed all year round.
Climate Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologi ...
and the availability of food resources are important influences on the timing of procellariid breeding; species that breed at higher
latitude In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north ...
s always breed in the summer as conditions are too harsh in the winter. At lower latitudes many, but not all, species breed continuously. Some species breed seasonally to avoid competition with other species for burrows, to avoid predation or to take advantage of seasonally abundant food. Others, such as the tropical wedge-tailed shearwater, breed seasonally for unknown reasons. Among the species that exhibit seasonal breeding there can be high levels of synchronization, both of time of arrival at the colony and of lay date. Procellariids begin to attend their nesting colony around one month prior to laying. Males will arrive first and attend the colony more frequently than females, partly in order to protect a site or burrow from potential competitors. Prior to laying there is a period known as the pre-laying exodus in which both the male and female are away from the colony, building up reserves in order to lay and undertake the first incubation stint respectively. This pre-laying exodus can vary in length from 9 days (as in the Cape petrel) to around 50 days in Atlantic petrels. All procellariids lay a single white egg per pair per breeding season, in common with the rest of the Procellariiformes. The egg is large compared to that of other birds, weighing 6–24% of the female's weight. Immediately after laying the female goes back to sea to feed while the male takes over incubation. Incubation duties are shared by both sexes in shifts that vary in length between species, individuals and the stage of incubation. The longest recorded shift was 29 days by a Murphy's petrel from Henderson Island; the typical length of a
gadfly petrel The gadfly petrels or ''Pterodroma'' are a genus of about 35 species of petrels, part of the seabird order Procellariiformes. The gadfly petrels are named for their speedy weaving flight, as if evading gadflies ( horseflies). The flight action is ...
stint is between 13 and 19 days. Fulmarine petrels, shearwaters and prions tend to have shorter stints, averaging between 3 and 13 days. Incubation takes a long time, from 40 days for the smaller species (such as prions) to around 55 days for the larger species. The incubation period is longer if eggs are abandoned temporarily; procellariid eggs are resistant to chilling and can still hatch after being left unattended for a few days. After hatching the chick is brooded by a parent until it is large enough to
thermoregulate Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature ...
efficiently, and in some cases defend itself from predation. This guard stage lasts a short while for burrow-nesting species (2–3 days) but longer for surface nesting
fulmar The fulmars are tubenosed seabirds of the family Procellariidae. The family consists of two extant species and two extinct fossil species from the Miocene. Fulmars superficially resemble gulls, but are readily distinguished by their flight on ...
s (around 16–20 days) and
giant petrel Giant petrels form a genus, ''Macronectes'', from the family Procellariidae, which consists of two species. They are the largest birds of this family. Both species are restricted to the Southern Hemisphere, and though their distributions overla ...
s (20–30 days). After the guard stage both parents feed the chick. In many species the parent's foraging strategy alternates between short trips lasting 1–3 days and longer trips of 5 days. The shorter trips, which are taken over the continental shelf, benefit the chick with faster growth, but longer trips to more productive
pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or w ...
feeding grounds are needed for the parents to maintain their own body condition. The meals are composed of both prey items and stomach oil, an
energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of ...
-rich food that is lighter to carry than undigested prey items. This oil is created in a stomach organ known as a proventriculus from digested prey items, and gives procellariids and other Procellariiformes their distinctive musty smell. Chick development is quite slow for
bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...
s, with fledging taking place at around two months after hatching for the smaller species and four months for the largest species. The chicks of some species are abandoned by the parents; parents of other species continue to bring food to the nesting site after the chick has left. Chicks put on weight quickly and some can outweigh their parents, although they will slim down before they leave the nest. All procellariid chicks fledge by themselves, and there is no further parental care after fledging. Life expectancy of Procellariidae is between 15 and 20 years; the oldest recorded member was a
northern fulmar The northern fulmar (''Fulmarus glacialis''), fulmar, or Arctic fulmar is a highly abundant seabird found primarily in subarctic regions of the North Atlantic and North Pacific oceans. There has been one confirmed sighting in the Southern Hem ...
that was over 50 years.


Relationship with humans


Exploitation

Procellariids have been a seasonally abundant source of food for people wherever people have been able to reach their colonies. Early records of human exploitation of shearwaters (along with albatrosses and
cormorant Phalacrocoracidae is a family of approximately 40 species of aquatic birds commonly known as cormorants and shags. Several different classifications of the family have been proposed, but in 2021 the IOC adopted a consensus taxonomy of seven ge ...
s) come from the remains of
hunter-gatherer A traditional hunter-gatherer or forager is a human living an ancestrally derived lifestyle in which most or all food is obtained by foraging, that is, by gathering food from local sources, especially edible wild plants but also insects, fung ...
midden A midden (also kitchen midden or shell heap) is an old dump for domestic waste which may consist of animal bone, human excrement, botanical material, mollusc shells, potsherds, lithics (especially debitage), and other artifacts and eco ...
s in southern Chile, where sooty shearwaters were taken 5000 years ago. More recently, procellariids have been hunted for food by Europeans, particularly the northern fulmar in Europe, and various species by
Inuit Inuit (; iu, ᐃᓄᐃᑦ 'the people', singular: Inuk, , dual: Inuuk, ) are a group of culturally similar indigenous peoples inhabiting the Arctic and subarctic regions of Greenland, Labrador, Quebec, Nunavut, the Northwest Territorie ...
, and sailors around the world. The hunting pressure on the
Bermuda petrel The Bermuda petrel (''Pterodroma cahow'') is a gadfly petrel. Commonly known in Bermuda as the cahow, a name derived from its eerie cries, this nocturnal ground-nesting seabird is the national bird of Bermuda and can be found pictured on Bermudi ...
, or cahow, was so intense that the species nearly became extinct and did go missing for 300 years. The name of one species, the providence petrel, is derived from its (seemingly) miraculous arrival on
Norfolk Island Norfolk Island (, ; Norfuk: ''Norf'k Ailen'') is an external territory of Australia located in the Pacific Ocean between New Zealand and New Caledonia, directly east of Australia's Evans Head and about from Lord Howe Island. Together wit ...
, where it provided a windfall for starving European settlers; within ten years the providence petrel was extinct on Norfolk. Several species of procellariid have gone extinct in the Pacific since the arrival of humans, and their remains have been found in middens dated to that time. More sustainable shearwater harvesting industries developed in
Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...
and New Zealand, where the practice of harvesting what are known as muttonbirds continues today.


Threats and conservation

While some species of procellariid have populations that number in the millions, many species are much less common and several are threatened with
extinction Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the Endling, last individual of the species, although the Functional ext ...
. Human activities have caused dramatic declines in the numbers of some species, particularly species that were originally restricted to one island. According to the
IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
43 species are listed as vulnerable or worse, with 12 critically endangered. Procellariids are threatened by many threats, but
introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...
on their breeding grounds,
light pollution Light pollution is the presence of unwanted, inappropriate, or excessive use of artificial lighting. In a descriptive sense, the term ''light pollution'' refers to the effects of any poorly implemented lighting, during the day or night. Light po ...
, marine
fisheries Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, ...
particularly bycatch, pollution, exploitation and
climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...
are the main threats measures as the number of species involved. The most pressing threat for many species, particularly the smaller ones, comes from species introduced to their colonies. Procellariids overwhelmingly breed on islands away from land predators such as mammals, and for the most part have lost the defensive adaptations needed to deal with them (with the exception of the oil-spitting fulmarine petrels). The introduction of mammal predators such as
feral cat A feral cat or a stray cat is an unowned domestic cat (''Felis catus'') that lives outdoors and avoids human contact: it does not allow itself to be handled or touched, and usually remains hidden from humans. Feral cats may breed over dozens ...
s, rats,
mongoose A mongoose is a small terrestrial carnivorous mammal belonging to the family Herpestidae. This family is currently split into two subfamilies, the Herpestinae and the Mungotinae. The Herpestinae comprises 23 living species that are native to so ...
s and mice can have disastrous results for ecologically naïve seabirds. These predators can either directly attack and kill breeding adults, or, more commonly, attack eggs and chicks. Burrowing species that leave their young unattended at a very early stage are particularly vulnerable to attack. Studies on
grey-faced petrel The grey-faced petrel (''Pterodroma gouldi'') is a petrel endemic to the North Island of New Zealand. In New Zealand it is also known by its Māori name and (along with other species such as the sooty shearwater) as a muttonbird. Taxonomy Th ...
s breeding on New Zealand's Whale Island (Moutohora) have shown that a population under heavy pressure from Norway rats will produce virtually no young during a breeding season, whereas if the rats are controlled (through the use of poison), breeding success is much higher. That study highlighted the role that non-predatory introduced species can play in harming seabirds; introduced
rabbit Rabbits, also known as bunnies or bunny rabbits, are small mammals in the family Leporidae (which also contains the hares) of the order Lagomorpha (which also contains the pikas). ''Oryctolagus cuniculus'' includes the European rabbit sp ...
s on the island caused little damage to the petrels, other than damaging their burrows, but they acted as a food source for the rats during the non-breeding season, which allowed rat numbers to be higher than they otherwise would be, resulting in more predators for the petrels to contend with. Interactions with introduced species can be quite complex. Gould's petrels breed only on two islands, Cabbage Tree Island and Boondelbah Island off Port Stephens (New South Wales). Introduced rabbits destroyed the forest understory on Cabbage Tree Island; this both increased the vulnerability of the petrels to natural predators and left them vulnerable to the sticky fruits of the birdlime tree (''
Pisonia umbellifera ''Ceodes umbellifera'', synonym ''Pisonia umbellifera'', commonly known as the birdlime tree or bird catcher tree, is a species of plant in the Nyctaginaceae family. The evergreen shrub has soft wood, small pink or yellow flowers, and produces ca ...
''), a native plant. In the natural state these fruits lodge in the understory of the forest, but with the understory removed the fruits fall to the ground where the petrels move about, sticking to their feathers and making flight impossible. Larger species of procellariid face similar problems to the albatrosses with long-line fisheries. These species readily take offal from fishing boats and will steal bait from the long lines as they are being set, risking becoming snared on the hooks and drowning. In the case of the
spectacled petrel The spectacled petrel (''Procellaria conspicillata'') is a rare seabird that nests only on the high western plateau of Inaccessible Island in the South Atlantic Tristan da Cunha group. It is one of the largest petrels that nests in burrows. This ...
this has led to the species undergoing a large decline and its listing as vulnerable. Diving species, most especially the shearwaters, are also vulnerable to
gillnet Gillnetting is a fishing method that uses gillnets: vertical panels of netting that hang from a line with regularly spaced floaters that hold the line on the surface of the water. The floats are sometimes called "corks" and the line with corks is ...
fisheries. Studies of gill-net fisheries show that shearwaters (sooty and short-tailed) compose 60% of the seabirds killed by gill-nets in Japanese waters and 40% in Monterey Bay, California in the 1980s, with the total number of shearwaters killed in Japan being between 65,000 and 125,000 per annum over the same study period (1978–1981). Procellariids are vulnerable to other threats as well. Ingestion of plastic flotsam is a problem for the family as it is for many other seabirds. Once swallowed, this plastic can cause a general decline in the fitness of the bird, or in some cases lodge in the gut and cause a blockage, leading to death by starvation. Procellariids are also vulnerable to general marine pollution, as well as oil spills. Some species, such as the Barau's petrel, the
Newell's shearwater Newell's shearwater or Hawaiian shearwater (''ʻaʻo''), (''Puffinus newelli'') is a seabird in the family Procellariidae. It belongs to a confusing group of shearwaters which are difficult to identify and whose classification is controversial. ...
or the
Cory's shearwater Cory's shearwater (''Calonectris borealis'') is a large shearwater in the seabird family Procellariidae. It breeds colonially of rocky islands in the eastern Atlantic. Outside the breeding season it ranges widely in the Atlantic. It was formerl ...
, which nest high up on large developed islands are victims of light pollution. Chicks that are fledging are attracted to streetlights and are unable to reach the sea. An estimated 20–40% of fledging Barau's petrels are attracted to the streetlights on Réunion. Conservationists are working with governments and fisheries to prevent further declines and increase populations of endangered procellariids. Progress has been made in protecting many colonies where most species are most vulnerable. On 20 June 2001, the
Agreement on the Conservation of Albatrosses and Petrels The Agreement on the Conservation of Albatrosses and Petrels (ACAP) is a legally binding international agreement signed in 2001 and entered into force on 1 February 2004 when South Africa ratified as the fifth Party to the Agreement. It was crea ...
was signed by seven major fishing nations. The agreement lays out a plan to manage fisheries by-catch, protect breeding sites, promote conservation in the industry, and research threatened species. The developing field of
island restoration The ecological restoration of islands, or island restoration, is the application of the principles of ecological restoration to islands and island groups. Islands, due to their isolation, are home to many of the world's endemic species, as well as ...
, where introduced species are removed and native species and habitats restored, has been used in several procellariid recovery programmes. Invasive species such as rats, feral cats and pigs have been either removed or controlled in many remote islands in the tropical Pacific (such as the
Northwestern Hawaiian Islands The Northwestern Hawaiian Islands or Leeward Hawaiian Islands are a series of islands and atolls in the Hawaiian island chain located northwest (in some cases, far to the northwest) of the islands of Kauai and Niihau. Politically, they are all ...
), around New Zealand (where island restoration was developed), and in the south Atlantic and
Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by ...
s. The grey-faced petrels of Whale Island (mentioned above) have been achieving much higher fledging successes after the introduced Norway rats were finally completely removed. At sea, procellariids threatened by long-line fisheries can be protected using techniques such as setting long-line bait at night, dying the bait blue, setting the bait underwater, increasing the amount of weight on lines and using bird scarers can all reduce the seabird by-catch. The Agreement on the Conservation of Albatrosses and Petrels came into force in 2004 and has been ratified by eight countries, Australia, Ecuador, New Zealand, Spain, South Africa, France, Peru and the United Kingdom. The treaty requires these countries to take specific actions to reduce by-catch and pollution and to remove introduced species from nesting islands.


See also

* List of Procellariidae species


References


Sources

* * * * *


External links


The Agreement for the Conservation of Albatrosses and Petrels (ACAP)
Treaty Website

Don Roberson's family page {{Featured article Bird families Seabirds Extant Rupelian first appearances Taxa named by William Elford Leach