Albatrosses are long-distance travellers. Normally, they fly by dynamic soaring, using the gradient in wind speed that exists between the sea surface and higher up. They also take advantage of the curtain of wind deflected up from the windward face of a wave – so-called slope soaring. Both methods of flight are fast and energy efficient, allowing albatrosses to cover long distances without the need to feed continuously.
Albatrosses are among the top predators and scavengers of the oceans. The food available at the surface consists mainly of crustaceans, squid, fish and carrion. Squid is usually the most important food, but in some areas shoaling fish and discards from fishing activities make up a large proportion of their diet. It is not uncommon to see large numbers of a variety of albatrosses around the stern of a fishing boat.
Albatrosses usually seize their prey from the surface of the sea, although they sometimes plunge from a few metres and use their half-opened wings to swim briefly below the surface. Small fish such as pilchards may be swallowed while the birds are in flight, but for larger prey albatrosses land on the sea before swallowing.
Royal world tour
Northern royal albatrosses have been tracked using satellite transmitters. After breeding, they disperse east from Taiaroa Head and the Chatham Islands to locations off Chile, and then off Argentina and Uruguay in South Atlantic waters, where they remain until near the start of the next breeding season. To return to New Zealand to breed, the birds migrate rapidly eastwards below South Africa and Australia, travelling with the prevailing winds and circumnavigating the southern hemisphere.
Looking for food
During their lifetime albatrosses cover vast distances over large areas of ocean in search of food. When breeding, they are more restricted in their choice of feeding area as they have to return to their nest. Even so, breeding albatrosses forage considerable distances over well-defined areas of ocean, which vary depending upon the stage of the breeding cycle.
For example, four distinct patterns of foraging area were identified for Buller’s albatrosses at the Snares Islands. During incubation, the off-duty parent made trips averaging 12 days, ranging as far as 1,500 kilometres over the Tasman Sea or 750 kilometres along the east coast of the South Island of New Zealand. After the eggs had hatched, while the chick was guarded, the adults made daily trips extending about 200 kilometres east of the Snares. When the chick was large enough to be left alone at the nest, the parents alternated between short trips (1–2 days, 200 kilometres) east of the Snares to long trips (5–6 days, 780 kilometres) along the east coast of the South Island. Finally, when the chick was within a few weeks of fledging, female parents switched to feeding off the west coast of the South Island (trips of 4–5 days and 650 kilometres) and male parents resorted to trips of about 2 days and 300 kilometres around Stewart Island.
After breeding, adults travel even longer distances. For example, Antipodean, Buller’s, Salvin’s and Chatham Island albatrosses cross the Pacific Ocean to forage off the coast of Chile and Peru. Southern and northern royal albatrosses travel even further, to feed off the coast of Argentina in the South Atlantic Ocean. Less is known about the movements of young birds in the years before they breed.