White-chinned petrel | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Procellariiformes |
Family: | Procellariidae |
Genus: | Procellaria |
Species: | P. aequinoctialis |
Binomial name | |
Procellaria aequinoctialis | |
Subspecies | |
| |
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 breeds colonially on scattered islands. The white-chinned petrel was formerly considered to be conspecific with the spectacled petrel (Procellaria conspicillata).
In 1747 the English naturalist George Edwards included an illustration and a description of the white-chinned petrel in the second volume of his A Natural History of Uncommon Birds. He used the English name "The great Black Peteril" and based his hand-coloured etching on a preserved specimen that had been brought to London. He believed that it had been collected near the Cape of Good Hope. [2] When in 1758 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the tenth edition, he placed the white-chinned petrel with the other petrels in the genus Procellaria . Linnaeus included a brief description, coined the binomial name Procellaria aequinoctialis and cited Edwards' work. [3]
There are two subspecies: [4]
Both subspecies were formerly considered synonymous with each other, but were recognized as distinct by the International Ornithological Congress in 2022 based on strong genetic distinctiveness. [4]
The genus name Procellaria is from the Latin procella meaning "storm" or "gale. The specific epithet aequinoctialis is Latin meaning equinoctial (aequinoctium is the Latin word for "equinox"). [5] The word petrel is derived from Saint Peter and the story of his walking on water, referring to their appearing to run on the water's surface when taking to the air. [6] Other English names for this species are Cape hen and shoemaker. [7]
The white-chinned petrel is a member of the family Procellariidae, and the order Procellariiformes. As a member of the Procellariiformes, they share certain identifying features. First, they have nasal passages that attach to the upper bill called naricorns. Although the nostrils on the petrel are on top of the upper bill. The bills of Procellariiformes are also unique in that they are split into between seven and nine horny plates. They produce a stomach oil made up of wax esters and triglycerides that is stored in the proventriculus. This can be sprayed out of their mouths as a defence against predators and as an energy rich food source for chicks and for the adults during their long flights. [8] Finally, they also have a salt gland that is situated above the nasal passage and helps desalinate their bodies, due to the high amount of ocean water that they imbibe. It excretes a high saline solution from the nose. [9]
The white-chinned petrel measures 51–58 cm (20–23 in) in length and has a wingspan of 134–147 cm (53–58 in). Males are heavier and average 1,390 g (49 oz) whereas females weigh around 1,280 g (45 oz). Not only is it the largest Procellaria petrel but is also the largest species in its family outside of the giant petrels. This large petrel is sooty-black and has some white on its throat and chin, more so in the Indian Ocean sector than the Atlantic. Its primaries can have a silvery appearance underneath. Its bill may be horn or yellow with some black between the nostrils. It has black legs and feet. When it flies, it mixes slow wing beats with glides. Although normally quiet, it will rattle or groan while at its colony. [7]
The white-chinned petrel utilises many islands during the breeding season. 2,000,000 pairs breed on South Georgia, Between 175,000 and 226,000 pairs are on the Kerguelen Islands, and 100,000 pairs on Disappointment Island. Some also breed on the Crozet Islands, Prince Edward Islands, Campbell Islands, Auckland Islands, Antipodes Islands, and the Falkland Islands. During the non-breeding season, the petrels fly from the Antarctic pack ice to the subtropics. [10]
The white-chinned petrel was recorded as a vagrant in Great Britain in May 2020, which was the second record of this species in the North Atlantic. [11]
Both sexes help to build a nest, and will help incubate the egg. Upon hatching, both sexes again will assist in feeding and protecting the young. [12]
Their diet is composed mainly of krill followed by fish. [13] White-chinned petrels feed by surface seizing and by undertaking shallow dives, [14] and they will readily follow ships to collect fisheries discards, [15] making them vulnerable to longline fisheries.
A 2004 estimate placed the adult population at 7,000,000 with an occurrence range of 44,800,000 km2 (17,300,000 sq mi). Mortality of both adults and chicks due to longline fisheries has caused the IUCN to classify it as vulnerable. [1] An overall decline in population is inferred by a drop in burrow occupancy rates of 28% at Bird Island, and an 86% reduction in population at Prydz Bay. Also, monitoring on Marion Island has shown of 14.5% reduction, and a 37% reduction on the Crozet Islands. [10] Unintentional death at the hands of longline fisheries has proven to be a major contributor to the overall population decline. Nearly all of the bycatch from the Namibian hake are white-chinned petrels. 10% of the South African pelagic longline bycatch and 55% of the demersal. Also, the white-chinned petrel has suffered at the hands of invasive species such as the brown rat, Rattus novegicus, and the black rat, Rattus rattus. [10]
Several of the breeding islands are protected areas. Ongoing studies and population monitoring are occurring at South Georgia, the Prince Edward Islands, Kerguelen Islands, and Crozet Islands. Finally, they are a part of ACAP Annex I, and CMS Appendix II. [10]
To assist in reversing the decline in population it has been proposed to continue and extend monitoring studies, trying to eliminate most invasive species, promote adoption of best practice mitigation measures at all fisheries within the range via ACAP, FAO, CCAMLR. [10]
Location | Population | Date | Trend |
South Georgia | < 2,000,000 pairs | 2004 | Decreasing 28% per 20 years |
Antipodes Island | 100,000+ pairs | 2000 | |
Disappointment Island | 100,000+ pairs | 2000 | |
Kerguelen Islands | 175,000-226,000 pairs | 1989 | |
Crozet Islands | 23,600 pairs | 1989 | Decreasing 37% per 21 years |
Campbell Islands exc. Campbell Island | 10,000+ pairs | ||
Falkland Islands | 55 pairs | ||
Prince Edward Island | Decreasing 14.5% per year | ||
Auckland Islands | |||
Total | 7,000,000 | 2004 | Decreasing 30% to 49% per 60 yr |
The black-browed albatross, also known as the black-browed mollymawk, is a large seabird of the albatross family Diomedeidae; it is the most widespread and common member of its family.
Pachyptila is a genus of seabirds in the family Procellariidae and the order Procellariiformes. The members of this genus and the blue petrel form a sub-group called prions. They range throughout the southern hemisphere, often in the much cooler higher latitudes. Three species, the broad-billed prion, the Antarctic prion and the fairy prion, range into the subtropics.
The family Procellariidae is a group of seabirds that comprises the fulmarine petrels, the gadfly petrels, the diving petrels, the prions, and the shearwaters. This family is part of the bird order Procellariiformes, which also includes the albatrosses and the storm petrels.
The northern giant petrel, also known as Hall's giant petrel, is a large, predatory seabird of the southern oceans. Its range overlaps broadly with the range of the related southern giant petrel, albeit slightly further to the north.
The southern giant petrel, 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 petrel, though it overall is centered slightly further south. Adults of the two species can be distinguished by the colour of their bill-tip: greenish in the southern and reddish in the northern.
Salvin's albatross or Salvin's mollymawk, is a large seabird that breeds mainly on the Bounty Islands of New Zealand, with scant amounts on islands across the Southern Ocean. A medium-sized mollymawk, it was long considered to be a subspecies of the shy albatross.
The spectacled petrel 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 species was formerly considered to be a subspecies of the white-chinned petrel.
The grey-headed albatross also known as the gray-headed mollymawk, is a large seabird from the albatross family. It has a circumpolar distribution, nesting on isolated islands in the Southern Ocean and feeding at high latitudes, further south than any of the other mollymawks. Its name derives from its ashy-gray head, throat and upper neck.
Procellaria is a genus of Southern Ocean long-winged seabirds related to prions, and within the order Procellariiformes. The black petrel ranges in the Pacific Ocean, and as far north as Central America. The spectacled petrel is confined to the Atlantic Ocean, and the Westland petrel to the Pacific Ocean. The white-chinned and grey petrel range throughout the higher latitudes of the Southern Ocean.
The Indian yellow-nosed albatross is a member of the albatross family, and is the smallest of the mollymawks. In 2004, BirdLife International split this species from the Atlantic yellow-nosed albatross; however Clements has not split it yet, and the SACC has not either, but recognises the need for a proposal.
The blue petrel is a small seabird in the shearwater and petrel family, Procellariidae. This small petrel is the only member of the genus Halobaena, but is closely allied to the prions. It is distributed across the Southern Ocean but breeds at a few island sites, all close to the Antarctic Convergence zone.
The Cape petrel, also called the Cape pigeon, pintado petrel, or Cape fulmar, is a common seabird of the Southern Ocean from the family Procellariidae. It is the only member of the genus Daption, and is allied to the fulmarine petrels, and the giant petrels. They are extremely common seabirds with an estimated population of around 2 million.
The fairy prion 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. It is a small prion which frequents the low subantarctic and subtropic seas.
The Kerguelen petrel is a small 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 Ocean. It breeds on islands in the southern Atlantic and Indian Oceans.
The broad-billed prion is a small pelagic seabird in the shearwater and petrel family, Procellariidae. It is the largest prion, with grey upperparts plumage, and white underparts. The sexes are alike. It ranges from the southeast Atlantic to New Zealand mainly near the Antarctic Convergence. In the south Atlantic it breeds on Tristan da Cunha and Gough Island; in the south Pacific it breeds on islands off the south coast of South Island, New Zealand and on the Chatham Islands. It has many other names that have been used such as blue-billed dove-petrel, broad-billed dove-petrel, long-billed prion, common prion, icebird, and whalebird.
The Antarctic prion also known as the dove prion, or totorore in Māori, is the largest of the prions, a genus of small petrels of the Southern Ocean.
The great-winged petrel is a petrel living and breeding in the world's Southern Ocean.
Salvin's prion, also known as the medium-billed prion, is a species of seabird in the petrel family Procellariidae.
The grey petrel, also called the brown petrel, pediunker or grey shearwater is a species of seabird in the Procellariidae, or petrel family. It is pelagic and occurs in the open seas of the Southern Hemisphere, mainly between 32°S and 58°S.
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