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.

Shearwaters
Great shearwater
Great shearwater
Scientific classificationEdit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Procellariiformes
Family: Procellariidae
Diversity

3 genera and c. 30 species

Genera

Description

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These tubenose birds fly with stiff wings and use a "shearing" flight technique (flying very close to the water and seemingly cutting or "shearing" the tips of waves) to move across wave fronts with the minimum of active flight. This technique gives the group its English name.[1] Some small species, like the Manx shearwater are cruciform in flight, with their long wings held directly out from their bodies.

Behaviour

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Movements

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Many shearwaters are long-distance migrants, perhaps most spectacularly sooty shearwaters, which cover distances in excess of 14,000 km (8,700 mi) from their breeding colonies on the Falkland Islands (52°S 60°W) to as far as 70° north latitude in the North Atlantic Ocean off northern Norway, and around New Zealand to as far as 60° north latitude in the North Pacific Ocean off Alaska. A 2006 study found individual tagged sooty shearwaters from New Zealand migrating 64,000 km (40,000 mi) a year,[2] which gave them the then longest known animal migration ever recorded electronically (though subsequently greatly exceeded by a tagged arctic tern migrating 96,000 km (60,000 mi)[3]). Short-tailed shearwaters perform an even longer "figure of eight" loop migration in the Pacific Ocean from Tasmania to as far north as the Arctic Ocean off northwest Alaska. They are also long-lived: a Manx shearwater breeding on Copeland Island, Northern Ireland, was (as of 2003/2004) the oldest known wild bird in the world; ringed as an adult (when at least 5 years old) in July 1953, it was retrapped in July 2003, at least 55 years old (also now exceeded, by a Laysan albatross). Manx shearwaters migrate over 10,000 km (6,200 mi) to South America in winter, using waters off southern Brazil and Argentina, so this bird had covered a minimum of 1,000,000 km (620,000 mi) on migration alone.

Following the tracks of the migratory Yelkouan shearwater has revealed that this species never flies overland, even if it means flying an extra 1,000 km. For instance, during their seasonal migration towards the Black Sea they would circumvent the entire Peloponnese instead of crossing over the 6 km Isthmus of Corinth.[4]

Breeding

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Shearwaters come to islands and coastal cliffs only to breed. They are nocturnal at the colonial breeding sites, preferring moonless nights to minimize predation. They nest in burrows and often give eerie contact calls on their night-time visits. They lay a single white egg. The chicks of some species, notably short-tailed and sooty shearwaters, are subject to harvesting from their nest burrows for food, a practice known as muttonbirding, in Australia and New Zealand.

Feeding

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They feed on fish, squid, and similar oceanic food. Some will follow fishing boats to take scraps, commonly the sooty shearwater; these species also commonly follow whales to feed on fish disturbed by them. Their primary feeding technique is diving, with some species diving to depths of 70 m (230 ft).[2]

Taxonomy

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There are about 30 species: a few larger ones in the genera Calonectris and Ardenna and many smaller ones in Puffinus. Recent genomic studies show that Shearwaters form a clade with Procellaria, Bulweria and Pseudobulweria.[5] This arrangement contrasts with earlier conceptions based on mitochondrial DNA sequencing. [6][7][8]

List of species

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The group contains 3 genera with 32 species.[9]

There are two extinct species that have been described from fossils.

Phylogeny

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Phylogeny of the shearwaters based on a study by Joan Ferrer Obiol and collaborators published in 2022. Only 14 of the 21 recognised species in the genus Puffinus were included.[10]

Puffinus

Christmas shearwater Puffinus nativitatis

Fluttering shearwater Puffinus gavia

Hutton's shearwater Puffinus huttoni

Audubon's shearwater Puffinus lherminieri

Barolo shearwater Puffinus baroli

Boyd's shearwater Puffinus boydi

Manx shearwater Puffinus puffinus

Balearic shearwater Puffinus mauretanicus

Yelkouan shearwater Puffinus yelkouan

Little shearwater Puffinus assimilis

Subantarctic shearwater Puffinus elegans

Tropical shearwater Puffinus bailloni

Black-vented shearwater Puffinus opisthomelas

Newell's shearwater Puffinus newelli

Calonectris

Streaked shearwater Calonectris leucomelas

Cape Verde shearwater Calonectris edwardsii

Cory's shearwater Calonectris borealis

Scopoli's shearwater Calonectris diomedea

Ardenna

Buller's shearwater Ardenna bulleri

Wedge-tailed shearwater Ardenna pacifica

Short-tailed shearwater Ardenna tenuirostris

Sooty shearwater Ardenna grisea

Great shearwater Ardenna gravis

Flesh-footed shearwater Ardenna carneipes

Pink-footed shearwater Ardenna creatopus

References

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  1. ^ "Shearwaters". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  2. ^ a b Shaffer, Scott A.; Tremblay, Yann; Weimerskirch, Henri; Costa, Daniel P. (2006). "Migratory shearwaters integrate oceanic resources across the Pacific Ocean in an endless summer". PNAS. 103 (34): 12799–12802. Bibcode:2006PNAS..10312799S. doi:10.1073/pnas.0603715103. PMC 1568927. PMID 16908846.
  3. ^ "Arctic tern in record-breaking migration from Farne Islands". BBC. 7 June 2016. Retrieved 10 September 2024.
  4. ^ CIESM Seabird Project. 2021. https://ciesm.org/marine/programs/seabirds/track-seabirds-migrating-live/
  5. ^ Estandia, A; Chesser, RT; James, HF; Levy, MA; Ferrer Obiol, J; Bretagnolle, V; Gonzales-Solis, J; Welch, AJ (July 2021). "Substitution rate variation in a robust procellariiform seabird phylogeny is not solely explained by body mass, flight efficiency, population size or life history traits" (PDF). bioRxiv. doi:10.1101/2021.07.27.453752. S2CID 236502443.
  6. ^ Bretagnolle, Vincent; Attié, Carole; Pasquet, Eric (1998). "Cytochrome-B evidence for validity and phylogenetic relationships of Pseudobulweria and Bulweria (Procellariidae)" (PDF). The Auk. 115 (1): 188–195. doi:10.2307/4089123. JSTOR 4089123.
  7. ^ Nunn, Gary B.; Stanley, Scott E. (1998). "Body Size Effects and Rates of Cytochrome b Evolution in Tube-Nosed Seabirds". Molecular Biology and Evolution. 15 (10): 1360–1371. doi:10.1093/oxfordjournals.molbev.a025864. PMID 9787440. Corrigendum
  8. ^ Austin, Jeremy J. (1996). "Molecular Phylogenetics of Puffinus Shearwaters: Preliminary Evidence from Mitochondrial Cytochrome b Gene Sequences". Molecular Phylogenetics and Evolution. 6 (1): 77–88. Bibcode:1996MolPE...6...77A. doi:10.1006/mpev.1996.0060. PMID 8812308.
  9. ^ Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (August 2024). "Petrels, albatrosses". IOC World Bird List Version 14.2. International Ornithologists' Union. Retrieved 10 September 2024.
  10. ^ Ferrer Obiol, J.; James, H.F.; Chesser, R.T.; Bretagnolle, V.; González-Solís, J.; Rozas, J.; Welch, A.J.; Riutort, M. (2022). "Palaeoceanographic changes in the late Pliocene promoted rapid diversification in pelagic seabirds". Journal of Biogeography. 49 (1): 171–188. Bibcode:2022JBiog..49..171F. doi:10.1111/jbi.14291. hdl:2445/193747.
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