Wedge-tailed Shearwater
A species of Typical Shearwaters Scientific name : Ardenna pacifica Genus : Typical Shearwaters
Wedge-tailed Shearwater, A species of Typical Shearwaters
Botanical name: Ardenna pacifica
Genus: Typical Shearwaters
Content
Description General Info
Description
The wedge-tailed shearwater is the largest of the tropical shearwaters. The two colour morphs of the species are dark and pale; the pale morphs predominate in the North Pacific, the dark morph elsewhere. However, both morphs exist in all populations, and bear no relation to sex or breeding condition. The pale morph has grey-brown plumage on the back, head, and upper wing, and whiter plumage below. The darker morph has the same dark grey-brown plumage over the whole body. The species' common name is derived from the large, wedge-shaped tail, which may help the species glide. The bill is dark and legs are salmon pink, with the legs set far back on the body (in common with the other shearwaters) as an adaptation for swimming. This species is related to the pan-Pacific Buller's shearwater, which differs much in colour pattern, but also has a wedge tail and a thin, black bill. They make up the Thyellodroma group, a superspecies of the large shearwaters that were for a long time included in the genus Puffinus. 
Size
41 - 81 cm
Life Expectancy
29 years
Feeding Habits
Wedge-tailed Shearwater predominantly consumes a diet of fish, squid, and crustaceans, with a preference for goatfish. They forage pelagically, employing nocturnal hunting techniques to capture their prey in the open ocean, revealing their specialized dietary adaptations.
Habitat
Wedge-tailed Shearwater are widely distributed marine birds that inhabit subtropical and tropical regions of the Pacific and Indian Oceans. Characteristically found far out at sea, wedge-tailed Shearwater seldom approach land except for breeding, which occurs predominantly on isolated offshore islands or atolls. Their breeding grounds are diverse, ranging from flat areas to slopes, plateaus, and cliffs, and they may settle in forested regions or grasslands on these islands. The species is adapted to pelagic life, only venturing to inshore waters in some places like eastern Australia.
Dite type
Piscivorous
General Info
Behavior
The wedge-tailed shearwater breeds in colonies on small tropical islands. Breeding seasons vary depending on location, with synchronised breeding seasons more common at higher latitudes. Northern Hemisphere birds begin breeding around February, and Southern Hemisphere birds begin around September. Wedge-tailed shearwaters display natal philopatry, returning to their natal colony to begin breeding at the age of four. Wedge-tailed shearwaters are monogamous, forming a pair bond that lasts for several years. Divorce between pairs occurs after breeding seasons that end in failure. Nesting occurs either in burrows or sometimes on the surface under cover. Pairs call frequently as a pair, both to reinforce the pair bond and warn intruders away from their territory. Parents also call to their chicks. The call is long, with an inhaling component (OOO) and exhaling component (err); their Hawaiian name 'ua'u kani means moaning petrel. Both sexes participate in digging a burrow, or repairing the burrow from last year. Nesting burrows of other species are also used. The breeding season of the Bonin petrel in Hawaii is timed to avoid that of the wedge-tail; in years where Bonin petrel chicks are still in burrows when wedge-tails return to begin breeding, these chicks are killed or evicted. It attends these colonies nocturnally, although nonbreeding wedge-tails are often seen at the surface throughout the day and breeding birds rest outside their burrows before laying. Both sexes undertake a prelaying exodus to build up energy reserves; this usually lasts around 28 days. A single egg is laid, if that egg is lost, then the pair will not attempt another that season. After laying, the male usually undertakes the first incubation stint. Both sexes incubate the egg, in stints that can last up to 13 days. Incubation takes around 50 days. After hatching, the chick is brooded for up to 6 days, until it is able to thermoregulate, after which it is left alone in the nest while both parents hunt for food. It is initially fed with stomach oil, an energy-rich, waxy oil of digested prey created in the parent's gut; later, it is fed both solids and stomach oil. Like many procellariids, wedge-tailed shearwater parents alternate long and short trips to provide food, with the parents alternating between short foraging trips (1–4 days) and long trips (about 8 days), the two parents coordinating their feeding effort. Chicks increase in size to 560 g (20 oz) (larger than the adults), then drop to around 430 g (15 oz) before fledging. Fledging occurs after 103–115 days, after which the chick is independent of the adult. Known breeding colonies include: Pacific Missile Range Facility, Kauai, Hawaii Heron Island, Australia Lady Elliot Island, Australia Lord Howe Island, Australia Montague Island, Southern New South Wales, Australia North West Island, Australia Muttonbird Island, Coffs Harbour, Northern New South Wales, Australia Mānana Island, Hawaii, United States Mokuauia Island, Hawaii, United States Kupikipiki’o Pt., Hawaii, United States Ilot Maitre, Noumea, New Caledonia Round Island, Mauritius Ka'ena Point, Oahu, Hawaii Mañagaha, Saipan, CNMI San Benedicto Island, Revillagigedo Islands, Mexico Alphonse Island, Republic of Seychelles Bijoutier Island, Republic of Seychelles
Scientific Classification
Phylum
Chordates Class
Birds Order
Albatrosses and Petrels Family
Shearwaters and petrels Genus
Typical Shearwaters Species
Wedge-tailed Shearwater 
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