- Ardenna pacifica
Identification
There are two colour morphs of the species, dark and pale. The pale morph has a grey-brown back, head and upperwing, and whiter plumage below. The darker morph is the same dark grey-brown over the whole body. They have a large wedge-shaped tail, dark bill and flesh coloured legs. Both morphs exist in all populations, and bear no relation to sex or breeding condition. This and other species of Shearwater are also known collectively as Muttonbirds, due to the practice of harvesting the chicks for meat and oil in Australia and New Zealand.
Similar Species
The Pink-footed Shearwater has brighter pink legs, and most diagnostically, a light bill. The Wedge-tailed has a dark bill. Buller's Shearwater is closely related and has a wedgetail and thin black bill, but shows striking black and white diagonal wing bars in flight.
Distribution
Widespread over open ocean throughout the tropical Pacific roughly between latitudes 35°N and 35°S, and off such islands Japan, the Hawaiian Islands, the Seychelles and Western Australia. The pale morph predominates in the north Pacific, the dark morph elsewhere.
Taxonomy
Formerly placed in genus Puffinus.
Subspecies
Two subspecies are recognized[1].
- A. p. pacifica
- Breeds Norfolk Island, the Kermadec Islands, Fiji and Tonga, ranging to the southeastern part of the North Pacific Ocean
- A. p. chlororhyncha
- Tropical and subtropical Indian and Pacific Oceans, breeding from the Madagascar area east to western Australia, and from southern Japan south to eastern Australia, Lord Howe Island, and New Caledonia east to the Marquesas Islands, Pitcairn Island, and the Revillagigedo Islands (off western Mexico)
Habitat
Islands and open sea.
Behaviour
- Diet: Includes fish, squid and crustaceans.
- Breeding: Both sexes dig a burrow for a nest; 1 egg is laid and incubated by both sexes in shifts for 50 days.
References
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, S. M. Billerman, T. A. Fredericks, J. A. Gerbracht, D. Lepage, B. L. Sullivan, and C. L. Wood. 2021. The eBird/Clements checklist of Birds of the World: v2021. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/
Recommended Citation
- BirdForum Opus contributors. (2024) Wedge-tailed Shearwater. In: BirdForum, the forum for wild birds and birding. Retrieved 18 April 2024 from https://www.birdforum.net/opus/Wedge-tailed_Shearwater
External Links
GSearch checked for 2020 platform.
