albatross

The wandering albatross Diomedea exulans. The young are cared for by both parents for almost a year, so breeding takes place every two years. Courtship involves elaborate displays of dancing, bill-rubbing, and wing-spreading.

Large seabird, genus Diomedea, with long narrow wings adapted for gliding and a wingspan of up to 3.4 m/11 ft, mainly found in the southern hemisphere. It belongs to the family Diomedeidae, order Procellariiformes, the same group as petrels and shearwaters. The nostrils of birds in this order are tubular, and the bills are hooked.

Albatrosses feed mainly on squid and fish, and nest on remote oceanic islands. They can cover enormous distances, flying as far as 16,100 km/10,000 mi in 33 days, or up to 640 km/600 mi in one day. They fly at speeds of up to 53.5 kph/50 mph, and continue flying even after dark, though they may stop for an hour's rest and to feed during the night. Albatrosses are becoming increasingly rare, and are in danger of extinction.

The Diomedeidae family contains 14 species of albatross found in the South Atlantic and the Pacific oceans. A single white egg is laid. The chick's full weight is 12 kg/26 lb, heavier than the parents, which typically weigh around 9 kg/20 lb. The chick needs this extra body weight to survive the Antarctic winter; the parents only return to the chick if and when they find food for it. The lack of readily available food means that 50% of the chicks will starve.

Flight Albatrosses may maintain gliding flight without flapping their wings for hours on end. To do this they make use of the steady trade winds. The birds seldom come ashore, except at breeding time. The huge wingspan of the wandering albatross D. exulans, means that it has difficulty in taking off unless there are strong winds. For this reason it nests on cliffs on islands.

Breeding Albatrosses are largely monogamous, returning to mate with the same partner at the same breeding site for a full lifespan, up to 20 years. They can spend up to a year rearing their young. The grey-headed albatross D. chrysostoma, for example, which breeds on South Georgia and other islands, takes 70 days to incubate the single egg; the male and female take turns on the egg, while the other parent collects food. The chick does not leave the nest for a further 141 days. For this reason the grey-headed albatross only breeds every other year. It is often found sharing a breeding ground with the black-browed albatross D. melanophris, which has a much shorter breeding cycle, and breeds every year.

Research published by German and French biologists in September 2000 indicated that throughout their lives, albatrosses always returned to the same stretch of ocean to breed, flying up to 8,500 km/5,280 mi to reach it.

Conservation In March 2001, an agreement to protect albatrosses and petrels was sanctioned by 12 nations. It is feared that 26 species are facing extinction, owing to habitat degradation, disturbance of breeding sites, and longline fishing. In the southern hemisphere, more than 40,000 albatrosses drown each year as a result of catching squid attached to bait lines.