Wedge-tailed Shearwater

Puffinus pacificus
Wedge-tailed shearwater

Wedgies are a medium sized bird with a long wedge-shaped tail. They have a slate colored bill that turns down at the end and flesh colored legs. There are 2 morphs of the wedge-tailed shearwater. The light morph is dark brown above with grayish white below. The dark morph is dark brown above with dark gray below. Loud groans, moans and wails resulted in the nickname "moaning bird". Vocalizations occur primarily at night in breeding colonies.

Wedge-tails 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.

 

Wedge-tailed shearwaters have previously nested on the southwestern side of the cleared area on Wilkes Island, to the north and west of the twisted metal rods. Two colonies of wedge-tailed shearwaters developed on Wake Island following the elimination of feral cats. One colony developed in the vicinity of the MDA and 1 near the fuel farm. The colonies were greatly affected by the storm surge associated with Typhoon Ioke.

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)