Giant petrel

Giant petrels form a genus, Macronectes, from the family Procellariidae, which consists of two living and one extinct species. They are the largest birds in this family. The living species are restricted to the Southern Hemisphere, and though their distributions overlap significantly, with both species breeding on the Prince Edward Islands, Crozet Islands, Kerguelen Islands, Macquarie Island, and South Georgia, many southern giant petrels nest farther south, with colonies as far south as Antarctica. Giant petrels are extremely aggressive predators and scavengers, inspiring another common name, the stinker.[2] South Sea whalers used to call them gluttons.[citation needed] They are the only member of their family that is capable of walking on land.[3]

Giant petrel
Temporal range: Pliocene[1]recent
Antarctic, Giant petrel (js) 55.jpg
Southern giant petrel juvenile
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Procellariiformes
Family: Procellariidae
Genus: Macronectes
Richmond, 1905
Type species
Procellaria gigantea (southern giant petrel)
Gmelin, 1789
Species

Macronectes giganteus
Southern giant petrel
Macronectes halli
Northern giant petrel Macronectes tinae
Tina's giant petrel

TaxonomyEdit

The genus Macronectes was introduced in 1905 by the American ornithologist Charles Wallace Richmond to accommodate what is now the southern giant petrel. It replaced the previous genus Ossifraga which was found to have been earlier applied to a different group of birds.[4][5] The name Macronectes combines the Ancient Greek makros meaning "great" and nēktēs meaning "swimmer".[6]

The present-day giant petrels are two large seabirds from the genus Macronectes. Long considered to be conspecific (they were not established as separate species until 1966),[7] the two species, the southern giant petrel, M. giganteus, and northern giant petrel, M. halli, are considered with the two fulmars, Fulmarus, to form a distinct subgroup within the Procellariidae, and including the Antarctic petrel, Cape petrel, and snow petrel, they form a separate group from the rest of the family.[8]

A fossil giant petrel, Macronectes tinae is known from the Pliocene epoch of New Zealand.[1]

Image Scientific name Common name Distribution
  Macronectes giganteus Southern giant petrel, Antarctic giant petrel, giant fulmar, stinker, and stinkpot from Antarctica to the subtropics of Chile, Africa, and Australia
  Macronectes halli Northern giant petrel or Hall's giant petrel Southern Ocean north of the Antarctic Convergence Zone, and north through Chile, Argentina, South Africa, and half of Australia.
  Macronectes tinae Tina's giant petrel, Taranaki giant petrel extinct (New Zealand, Pliocene)

DescriptionEdit

The southern giant petrel is slightly larger than the northern giant petrel, at 3 to 8 kg (6.6–17.6 lb), 180 to 210 cm (71–83 in) across the wings, and 86 to 100 cm (34–39 in) of body length.[2][9] The northern giant petrel is 3 to 5 kg (6.6–11.0 lb), 150 to 210 cm (59–83 in) across the wings and 80 to 95 cm (31–37 in) of body length.[10][11] They superficially resemble the albatross, and are the only procellarids that can equal them in size. They can be separated from the albatrosses by their bill; the two tube nostrils are joined together on the top of the bill, unlike on albatross, where they are separated and on the side of the bill. Giant petrels are also the only members of the family Procellariidae to have strong legs to walk on land.[2][3] They are also much darker and more mottled brown (except for the white morph southern, which are whiter than any albatross) and have a more hunch-backed look. The bills of Procellariiformes are also unique in that they are split into between seven and nine horny plates. The petrels have a hooked bill called the maxillary unguis which can hold slippery prey. They produce a stomach oil made up of wax esters and triglycerides which is stored in the proventriculus. This can be sprayed out of their mouths as a defence against predators and as a protein-rich food source for chicks and for the adults during their long flights.[12] Petrels have a salt gland situated above the nasal passage that helps to desalinate their bodies by excreting a high saline solution from their noses.[13]

The two species are difficult to tell from each other, possessing similar long, pale, orange bills and uniform, mottled grey plumage (except for around 15% of southern petrels, which are almost completely white). The billtip of M. halli is reddish-pink and that of M. giganteus is pale green, appearing slightly darker and lighter than the rest of the bill, respectively. The underside of older M. halli birds is paler and more uniform than M. giganteus, the latter showing a contrast between paler head and neck and darker belly.[14] Additionally, adults of M. halli typically appear pale-eyed, while adults of M. giganteus of the normal morph typically appear dark-eyed (occasionally flecked paler). Classic examples of northern giant are identifiable at some range. Young birds of both species are all dark and very hard to distinguish unless bill tip colour can be seen. Some relatively young northern giant petrels can appear to be paler on the head, suggesting southern giant, thus this species is harder to confirm.[citation needed]

The extinct Macronectes tinae is characterized by having smaller bodies than their living relatives.[1]


EtymologyEdit

Macronectes comes from the Greek words makros meaning "long" and nēktēs meaning "swimmer". Also, petrel is derived from St. Peter and the story of his walking on water, as they appear to run on the water when they take off.[15]

 
Giant petrel feeding on a seal carcass in South Georgia

BehaviourEdit

FeedingEdit

Petrels are highly opportunistic feeders. Unique among procellarids, they will feed both on land and at sea; in fact, they find most of their food near coastlines. On land, they feed on carrion,[2][14] and regularly scavenge the breeding colonies of penguins and seals. They will display their dominance over carcasses with a "sealmaster posture":[16] the head and the wings are held outstretched, the head pointing at the opponent and the wingtips pointing slightly back; the tail is raised to a vertical position. They are extremely aggressive and will kill other seabirds (usually penguin chicks, sick or injured adult penguins and the chicks of other seabirds), even those as large as an albatross, which they kill either by battering them to death or drowning.[17] At sea, they feed on krill, squid, and fish. They often follow fishing boats and other ships, in the hope of picking up offal and other waste.[14]

 
Giant petrel with chick in Antarctica

ReproductionEdit

The southern giant petrel is more likely to form loose colonies than the northern, both species laying a single egg in a rough nest built about 50 cm (20 in) off the ground. The egg is incubated for about 60 days; once hatched the chick is brooded for three weeks. Chicks fledge after about four months, but do not achieve sexual maturity for six or seven years after fledging.[2]

ConservationEdit

While both species were listed as near threatened in the 2008 IUCN Red List,[18][19] subsequent evidence suggested they were less threatened than previously believed, and the populations of both actually appeared to have increased, at least locally. Consequently, they were listed as least concern on the 2009 Red List[14][20] and afterwards (as of IUCN's last assessment in 2018, they continue to be listed as least concern).[21][22]

The southern giant petrel is listed as endangered on the Australian Environment Protection and Biodiversity Conservation Act 1999, while the northern giant petrel is listed on the same act as vulnerable.[10][23][24] Their conservation status also varies from state to state within Australia.[10][23]

Conservation Status of Macronectes species in Australian States
State Macronectes halli Macronectes giganteus
NSW Vulnerable[10][25] Endangered[23][26]
QLD Vulnerable[10][27] Endangered[23][27]
SA N/A Vulnerable[23][28]
TAS Rare[10][29] Vulnerable[23][29]
VIC Endangered[10][30] Endangered[23][30]

GalleryEdit

ReferencesEdit

  1. ^ a b c Tennyson, Alan J.D.; Salvador, Rodrigo B. (2023). "A new giant petrel (Macronectes, Aves: Procellariidae) from the Pliocene of Taranaki, New Zealand". Taxonomy. 3 (1): 57–67. doi:10.3390/taxonomy3010006.
  2. ^ a b c d e Maynard, B. J. (2003). "Shearwaters, petrels, and fulmars (Procellariidae)". In Hutchins, Michael; Jackson, Jerome A.; Bock, Walter J.; Olendorf, Donna (eds.). Grzimek's Animal Life Encyclopedia. Vol. 8 Birds I Tinamous and Ratites to Hoatzins. Joseph E. Trumpey, Chief Scientific Illustrator (2nd ed.). Farmington Hills, MI: Gale Group. pp. 123–133. ISBN 0-7876-5784-0.
  3. ^ a b "Giant Petrels". Oceanwide Expeditions. Archived from the original on 29 September 2022. Retrieved 28 September 2022.
  4. ^ Richmond, Charles Wallace (1905). "New generic name for the giant fulmar". Proceedings of the Biological Society of Washington. 18: 76 – via Biodiversity Heritage Library.
  5. ^ Mayr, Ernst; Cottrell, G. William, eds. (1979). Check-List of Birds of the World. Vol. 1 (2nd ed.). Cambridge, Massachusetts: Museum of Comparative Zoology. p. 59 – via Biodiversity Heritage Library.
  6. ^ Jobling, James A. (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. p. 236. ISBN 978-1-4081-2501-4.
  7. ^ Remsen Jr., J. V.; et al. (7 Aug 2008). "A classification of the bird species of South America South American Classification Committee American Ornithologists' Union". South American Classification Committee. American Ornithologists' Union. Retrieved 9 Jul 2009.
  8. ^ Tree of Life (27 Jun 2008). "Procellariidae. Shearwaters, Petrels". Tree of Life Web Project. Retrieved 18 Mar 2009.
  9. ^ "Southern Giant Petrel - Fact File". Heard Island. Australian Government. Archived from the original on 20 July 2008. Retrieved 23 September 2008.
  10. ^ a b c d e f g "Macronectes halli — Northern Giant Petrel". Species Profile and Threats Database. Australian Government. 2022. Archived from the original on 2 June 2011. Retrieved 2017-07-27.
  11. ^ "Northern Giant Petrel - Macronectes halli". Oiseaux. Archived from the original on 17 September 2018. Retrieved 27 July 2017.
  12. ^ Double, M. C. (2003). "Procellariiformes (Tubenosed Seabirds)". In Hutchins, Michael; Jackson, Jerome A.; Bock, Walter J.; Olendorf, Donna (eds.). Grzimek's Animal Life Encyclopedia. Vol. 8 Birds I Tinamous and Ratites to Hoatzins. Joseph E. Trumpey, Chief Scientific Illustrator (2nd ed.). Farmington Hills, MI: Gale Group. pp. 107–111. ISBN 0-7876-5784-0.
  13. ^ Ehrlich, Paul R.; Dobkin, David, S.; Wheye, Darryl (1988). The Birders Handbook (First ed.). New York, NY: Simon & Schuster. pp. 29–31. ISBN 0-671-65989-8.
  14. ^ a b c d BirdLife International (2009). "Southern Giant-petrel - BirdLife Species Factsheet". Bird Life International. Archived from the original on 1 December 2008. Retrieved 16 Mar 2009.
  15. ^ Gotch, A. F. (1995) [1979]. "Albatrosses, Fulmars, Shearwaters, and Petrels". Latin Names Explained A Guide to the Scientific Classifications of Reptiles, Birds & Mammals. New York, NY: Facts on File. p. 191. ISBN 0-8160-3377-3.
  16. ^ de Bruyn, P. J. N.; Cooper, J. (2005). "Who's the boss? Giant petrel arrival times and interspecific interactions at a seal carcass at sub-Antarctic Marion Island". Polar Biology. 28 (7): 571–573. doi:10.1007/s00300-005-0724-7. S2CID 43648629.
  17. ^ Cox, J. B. (1978). "Albatross Killed by Giant-petrel" (PDF). Emu. 78 (2): 94–95. doi:10.1071/MU9780094.
  18. ^ BirdLife International (2018). "Macronectes giganteus". IUCN Red List of Threatened Species. 2018: e.T22697852A132608499. doi:10.2305/IUCN.UK.2018-2.RLTS.T22697852A132608499.en. Retrieved 13 November 2021.
  19. ^ BirdLife International (2018). "Macronectes halli". IUCN Red List of Threatened Species. 2018: e.T22697859A132609000. doi:10.2305/IUCN.UK.2018-2.RLTS.T22697859A132609000.en. Retrieved 13 November 2021.
  20. ^ BirdLife International (2009). "Northern Giant-petrel - BirdLife Species Factsheet". BirdLife International. Archived from the original on 1 December 2008. Retrieved 9 June 2009.
  21. ^ BirdLife International (7 August 2018). "Macronectes giganteus". IUCN Red List of Threatened Species. 7 August 2018. doi:10.2305/IUCN.UK.2018-2.RLTS.T22697852A132608499.en. Retrieved 14 April 2021.
  22. ^ BirdLife International (7 August 2018). "Macronectes halli". IUCN Red List of Threatened Species. 7 August 2018. doi:10.2305/IUCN.UK.2018-2.RLTS.T22697859A132609000.en. Retrieved 14 April 2021.
  23. ^ a b c d e f g "Macronectes giganteus — Southern Giant-Petrel, Southern Giant Petrel". Species Profile and Threats Database. Australian Government. 2022. Archived from the original on 4 May 2022. Retrieved 29 September 2022.
  24. ^ "EPBC Act List of Threatened Fauna". Australian government: Department of the Environment, Water, Heritage and the Arts. Retrieved 25 July 2009.
  25. ^ "Northern Giant-Petrel - profile". NSW Government Office of Environment & Heritage. 13 January 2022. Retrieved 2022-09-29.
  26. ^ "Southern Giant Petrel - profile". NSW Government Office of Environment & Heritage. 13 January 2022. Retrieved 2022-09-29.
  27. ^ a b "Search threatened species". Microsoft Power BI. April 2022. Retrieved 2022-09-29.
  28. ^ "National Parks and Wildlife Act 1972" (PDF). Legislation South Australia. 2020. p. 24. Retrieved 29 September 2022.
  29. ^ a b "Threatened Species List - Vertebrate Animals". Department of Natural Resources and Environment Tasmania. 6 September 2022. Retrieved 29 September 2022.
  30. ^ a b "Flora and Fauna Guarantee Act 1988 - Threatened List" (PDF). Victoria State Government Environment, Land, Water and Planning. June 2022. p. 6. Retrieved 29 September 2022.

SourcesEdit

External linksEdit