Great shearwater

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Great shearwater
Greater shearwater (Ardenna gravis) Sagres.jpg
Ten miles off Sagres, Portugal
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Procellariiformes
Family: Procellariidae
Genus: Ardenna
Species:
A. gravis
Binomial name
Ardenna gravis
(O'Reilly, 1818)
Ardenna gravis map.svg
Synonyms
  • Procellaria gravis O'Reilly, 1818
  • Puffinus gravis (protonym)

The great shearwater (Ardenna gravis) is a large shearwater in the seabird family Procellariidae. It breeds colonially on rocky islands in the south Atlantic. Outside the breeding season it ranges widely in the Atlantic.

Contents

Taxonomy

The great shearwater was formally described in 1818 by the Irish naturalist Bernard O'Reilly and given the binomial name Procellaria gravis. [2] [3] The great shearwater is now placed in the genus Ardenna that was introduced in 1853 by Ludwig Reichenbach. [4] [5] The genus name Ardenna was used to refer to a seabird by Italian naturalist Ulisse Aldrovandi in 1603. The specific epithet gravis is Latin meaning "heavy" or "weighty". [6] The species is monotypic: no subspecies are recognised. [5]

Description

This shearwater is 43–51 cm (16.9–20.1 in) in length with a 105–122 cm (3.5–4.0 ft) wingspan. It is identifiable by its size, dark upper parts, and white under parts, with the exception of a brown belly patch and dark shoulder markings. It has a black cap, black bill, and a white "horseshoe" on the base of the tail. The stiff flight, like a large Manx shearwater, is also distinctive. The only other large shearwaters in its range are the Cory's Shearwater and the all-dark Sooty Shearwater.

In flight Puffinus gravis - SE Tasmania.jpg
In flight

Distribution and habitat

The great shearwater, like the sooty shearwater, follows a circular migration route, moving north up the eastern seaboard of first South and then North America, before crossing the Atlantic in August. It can be quite common off the southwestern coasts of Great Britain and Ireland before heading back south again, this time down the eastern littoral of the Atlantic.

Behaviour and ecology

This bird has the typically "shearing" flight of the genus, dipping from side to side on stiff wings with few wingbeats, the wingtips almost touching the water. Its flight is powerful and direct, with wings held stiff and straight.

Breeding

This species breeds on Nightingale Island, Inaccessible Island, Tristan da Cunha, and Gough Island. It is one of only a few bird species to migrate from breeding grounds in the Southern Hemisphere to the Northern Hemisphere, the normal pattern being the other way around. This shearwater nests in large colonies, laying one white egg in a small burrow or in the open grass. These nests are visited only at night to avoid predation by large gulls.

Great shearwater with plastic fragments found in its stomach Great Shearwater plastic fragments stomach.jpg
Great shearwater with plastic fragments found in its stomach

Food and feeding

The great shearwater feeds on fish and squid, which it catches from the surface or by plunge-diving. It occasionally feeds on crustaceans, fish entrails and other refuse discarded by fishing vessels. [8] It readily follows fishing boats, where it indulges in noisy squabbles. This is a gregarious species, which can be seen in large numbers from ships or appropriate headlands. They have a piercing "eeyah" cry usually given when resting in groups on the water.

Great shearwaters are among the seabird species with the highest incidence of plastic ingestion. [9]

Related Research Articles

<span class="mw-page-title-main">Shearwater</span> Seabird

Shearwaters are medium-sized long-winged seabirds in the petrel family Procellariidae. They have a global marine distribution, but are most common in temperate and cold waters, and are pelagic outside the breeding season.

<span class="mw-page-title-main">Procellariidae</span> Family of seabirds which includes petrels, shearweters and prions

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.

<span class="mw-page-title-main">Cory's shearwater</span> Species of bird

Cory's shearwater 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 formerly considered to be conspecific with Scopoli's shearwater.

<span class="mw-page-title-main">Northern fulmar</span> Species of bird

The northern fulmar, 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 Hemisphere, with a single bird seen south of New Zealand. Fulmars come in one of two color morphs: a light one, with white head and body and gray wings and tail, and a dark one, which is uniformly gray. Though similar in appearance to gulls, fulmars are in fact members of the family Procellariidae, which include petrels and shearwaters.

<span class="mw-page-title-main">Sooty shearwater</span> Species of bird

The sooty shearwater, or tītī, or muttonbird, is a medium-large shearwater in the seabird family Procellariidae. In New Zealand, it is also known by its Māori name tītī, and as muttonbird, like its relatives the wedge-tailed shearwater and the Australian short-tailed shearwater.

<span class="mw-page-title-main">Little shearwater</span> Species of bird

The little shearwater is a small shearwater in the petrel family Procellariidae. Despite the generic name, it is unrelated to the puffins, which are auks, the only similarity being that they are both burrow-nesting seabirds.

<i>Puffinus</i> Genus of birds

Puffinus is a genus of seabirds in the order Procellariiformes that contains about 20 small to medium-sized shearwaters. Two other shearwater genera are named: Calonectris, which comprises three or four large shearwaters, and Ardenna with another seven species.

<i>Calonectris</i> Genus of birds

Calonectris is a genus of seabirds. The genus name comes from Ancient Greek kalos, "good" and nectris, "swimmer".

<span class="mw-page-title-main">Christmas shearwater</span> Species of bird

The Christmas shearwater or ʻaoʻū is a medium-sized shearwater of the tropical Central Pacific. It is a poorly known species due to its remote nesting habits, and it has not been extensively studied at sea either.

<span class="mw-page-title-main">Wedge-tailed shearwater</span> Species of bird

The wedge-tailed shearwater is a medium-large shearwater in the seabird family Procellariidae. It is one of the shearwater species that is sometimes referred to as a muttonbird, like the sooty shearwater of New Zealand and the short-tailed shearwater of Australia. It is found throughout the tropical Pacific and Indian Oceans, roughly between latitudes 35°N and 35°S. It breeds on the islands off Japan, on the Islas Revillagigedo, the Hawaiian Islands, the Seychelles, the Northern Mariana Islands, and off Eastern and Western Australia.

<span class="mw-page-title-main">Audubon's shearwater</span> Species of bird

Audubon's shearwater is a common tropical seabird in the petrel family. Sometimes known as the dusky-backed shearwater, the specific epithet honours the French naturalist Félix Louis L'Herminier.

<span class="mw-page-title-main">Short-tailed shearwater</span> Species of bird

The short-tailed shearwater or slender-billed shearwater, also called yolla or moonbird, and commonly known as the muttonbird in Australia, is the most abundant seabird species in Australian waters, and is one of the few Australian native birds in which the chicks are commercially harvested. It is a migratory species that breeds mainly on small islands in Bass Strait and Tasmania and migrates to the Northern Hemisphere for the boreal summer.

<span class="mw-page-title-main">Flesh-footed shearwater</span> Species of bird

The flesh-footed shearwater is a medium-sized shearwater. Its plumage is black. It has pale pinkish feet, and a pale bill with a distinct black tip. Together with the equally light-billed pink-footed shearwater, it forms the Hemipuffinus group, a superspecies which may or may not have an Atlantic relative in the great shearwater. These large shearwaters are among those that have been separated into the genus Ardenna. Recent genetic analysis indicates evidence of strong divergence between Pacific colonies relative to those in South and Western Australia, thought to be explained by philopatry and differences in foraging strategies during the breeding season.

<span class="mw-page-title-main">Buller's shearwater</span> Species of bird

Buller's shearwater is a Pacific species of seabird in the family Procellariidae; it is also known as the grey-backed shearwater or New Zealand shearwater. A member of the black-billed wedge-tailed Thyellodroma group, among the larger shearwaters of the genus Ardenna, it forms a superspecies with the wedge-tailed shearwater.

<span class="mw-page-title-main">Pink-footed shearwater</span> Species of bird

The pink-footed shearwater is a species of seabird. The bird is 48 cm (19 in) in length, with a 109 cm (43 in) wingspan. It is polymorphic, having both darker- and lighter-phase populations. Together with the equally light-billed flesh-footed shearwater, it forms the Hemipuffinus group, a superspecies that may or may not have an Atlantic relative in the great shearwater. These are large shearwaters which are among those that could be separated in the genus Ardenna.

<i>Ardenna</i> Genus of birds

Ardenna is a genus of seabirds in the family Procellariidae. These medium-sized shearwater species were formerly included in the genus Puffinus.

References

  1. BirdLife International (2018). "Ardenna gravis". IUCN Red List of Threatened Species . 2018: e.T22698201A132633747. doi: 10.2305/IUCN.UK.2018-2.RLTS.T22698201A132633747.en . Retrieved 13 November 2021.
  2. O'Reilly, Bernard (1818). Greenland, the adjacent seas, and the North-west Passage to the Pacific Ocean, illustrated in a voyage to Davis's strait, during the summer of 1817. London: Craddock and Joy. p. 140, Plate 12 fig. 1.
  3. O'Connor, J. P. (1985). "Bernard O'Reilly: Genius or Rogue?". The Irish Naturalists' Journal. 21 (9): 379–384. JSTOR   25538895.
  4. Reichenbach, H. G. Ludwig (1853). Avium systema naturale. Dresden and Leipzig: Expedition der vollständigsten naturgeschichte. p. IV. The title page has 1850 (original title page missing in the BHL scan but available from BSB). The Preface is dated 1852 but the volume was not published until 1853.
  5. 1 2 Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (January 2022). "Petrels, albatrosses". IOC World Bird List Version 12.1. International Ornithologists' Union. Retrieved 19 February 2022.
  6. Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp.  54, 178. ISBN   978-1-4081-2501-4.
  7. Yamashita; et al. (2021). "Plastic additives and legacy persistent organic pollutants in the preen gland oil of seabirds sampled across the globe" (PDF). Environmental Monitoring and Contaminants Research. 1: 97–112. doi:10.5985/emcr.20210009. S2CID   241803983.
  8. "Puffinus gravis (Great shearwater)". Animal Diversity Web .
  9. Peter G. Ryan (1987). "The incidence and characteristics of plastic particles ingested by seabirds". Marine Environmental Research. 23 (3): 175–206. Bibcode:1987MarER..23..175R. doi:10.1016/0141-1136(87)90028-6.

Further reading