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Shy Albatross, Thalassarche cauta

The Shy Albatross, (Thalassarche cauta), also known as the Shy Mollymawk, is a species of albatross found off the coast of Australia and New Zealand’s sub-Antarctic islands. Its range extends across much of the Southern Ocean. It is also known as the White-capped Albatross in some areas.

This species at one time was considered to be the same species as Salvin’s Albatross and the Chatham Albatross, but was given its own species moniker in 2004. The Shy Albatross belongs to the Diomedeidae family. It is related to Shearwaters, Fulmars, Storm-petrels, and Diving-petrels, with which it shares certain identifiable features.

Like its relatives, the Shy Albatross has nasal passages that attach to the upper bill, although the nostrils are on the sides of the bill on this bird. Also, as with its relatives, it produces a stomach oil made up of wax esters and triglycerides that is stored in the proventriculus (the stomach’s glandular region). This is used against predators as well as an energy rich food source for chicks and for adults during their long flights. It also has a salt gland located above the nasal passage that helps desalinate their bodies due to the high amount of ocean water they ingest.

The adult of this species measures 35 to 39 inches in length with a 83 to 100 inch wingspan. It weighs from 5.7 to 12 pounds. The Shy Albatross is considered the largest of the Mollymawks. It is a black, white and slate-gray bird with the characteristic black thumb mark at the base of the leading edge of the underwing. The adult has a white forehead and a crown, which is bordered on the bottom with a dark eyebrow and pale gray face. The mantle, tail, and upperwing is grayish-black, and the rest is white. The bill is grayish-yellow with a prominent yellow summit and yellow tip.

The diet of the Shy Albatross consists of fish, cephalapods, crustaceans and tunicates, which it takes from the water as it dives — sometimes as deep as 16 feet under the surface. It breeds on rocky islands and builds a mounded nest of soil, grass and roots. The female lays one egg in the second half of September. Its breeding ground exists in three island colonies: Albatross Island, Pedra Branca, and the Mewstone.

During the breeding season, the adults concentrate around southern Australia and Tasmania. Juveniles are known to fly as far as South Africa; otherwise, non-breeding birds are found throughout the southern oceans. It is occasionally found off the Pacific coast of the United States.

The IUCN classifies the Shy Albatross as near threatened with and occurrence range of 14.8 million square miles. Population estimates put numbers of this species at 25,500 breeding birds with 5,100 pairs on Albatross Island, 270 pairs on Pedra Branca, and 7,380 on the Mewstone. Decline has been historically attributed to exploitation for the species’ feathers. By 1909 there were only 300 pairs left on Albatross Island.

Today, the biggest threats include longline fishing, although their numbers are maintaining. An avian pox outbreak on Albatross Island also impacted number slightly. The Australian Gannet is the primary threat to their survival.

Image Caption: Shy Albatross (Thalassarche cauta), East of the Tasman Peninsula, Tasmania, Australia. Credit: JJ Harrison/Wikipedia (CC BY-SA 3.0)

Shy Albatross Thalassarche cauta


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