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Wedge-tailed Shearwater

Puffinus pacificus / ‘Ua‘u Kani
Wedgetailed Shearwaters

Wedge-tails are dark brown to brownish-grey above with white underparts, except dark wing margins and undertail-coverts. They have a wedge-shaped tail and a slender, slate-grey hooked bill. Legs and feet are flesh colored. Loud groans, moans and wails resulted in island residents giving them the name "moaning bird". Vocalizations occur primarily at night in breeding colonies.

Wedgies are monogamous. Their courtship ritual begins shortly after arrival in late March. They return to the same nest site each year, nesting in shallow burrows, one to two meters in length. A pair will sit head to head, often near their burrow entrance, vocalizing two-part wailing duets. A single, large, white egg is laid in a nesting chamber at the end of burrow. Egg laying occurs throughout the month of June. No relaying will occur if an egg is lost. Incubation period averages 53 days with both parents alternating shifts on the egg, with each shift lasting as long as 12 days.

Chicks hatch during late July through late August. Parents feed regurgitated squid and stomach oil to chicks - feeding takes place every 24 hours. Fledging occurs in approximately 100-115 days. Parent desertion of the chick typically occurs shortly before fledging.

Approximately 1,000 nesting pairs nest on Sand and Eastern Islands. Wedge-tails breed widely in the tropical and subtropical waters of the Indian and Pacific Oceans.

Facts About Wedge-tailed Shearwater

Diet
Feed during the day singly or in multi-species flocks. Consumes larval forms of goat fish, mackerel scad, and flying squid driven to the surface by schools of predatory fish, such as skipjack tuna.
Life Span
10-11 years
Size
Length: 41-46 cm (16-18 in); wingspan: 97-104 cm (38-41 in) 
Page Photo Credits — Ian Jones/USFWS
Last Updated: Aug 29, 2013
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