The Laysan albatross (Phoebastria immutabilis ) is a large seabird that ranges across the North Pacific. The Northwestern Hawaiian Islands are home to 99.7% of the population. This small (for its family) gull-like albatross is the second-most common seabird in the Hawaiian Islands, with an estimated population of 1.18 million birds, and is currently expanding (or possibly re-expanding) its range to new islands. The Laysan albatross was first described as Diomedea immutabilis by Lionel Walter Rothschild, in 1893, on the basis of a specimen from Laysan Island.
The graceful glide of this bird among the waves and winds of the Pacific Ocean is a marvelous sight. The Laysan albatross is an expert soarer and can travel hundreds of miles in a day with scarcely a wing beat. Its name is due to being the only specimen that lives on Laysan Island. It nests on islands in the tropical Pacific, but will feed in Japan, California or the Aleutian Islands. In 1983 the famous British zoologist Lionel Walter Rothschild illustrated this species as Diomedia Immutabilis.
The Laysan albatross ranges over the northern Pacific Ocean from around the latitude of Costa Rica across to the Aleutian Islands and the southern Bering Sea. It spends most of its time on the open sea, spanning these tropical waters. It nests on open sandy or grassy expanses of islands, with 94% of breeding pairs on Laysan Island and Midway Atoll, as well as on other small Hawaiian Islands, the bigger islands of Oahu and Kauai, and a few sites off Japan and Mexico.
The classic behavior of an albatross is dynamic soaring, with very infrequent wing beats. It uses the speed and direction changes of wind at different heights to be able to fly great distances with only very slight changes to its wing position. On the ground it walks ponderously and usually has to run into the wind along the ground to take off. This species spends much time at sea, circling around for many years. Only during the mating period do they remain on the ground. They often “crash-land”, rolling head over heels. During the night they settle on the water to feed. Normally quiet and solitary when at sea, they may gather in large flocks to feed on discarded fish from factory trawlers. These birds seize food at the surface of the water and by shallow diving. Aside from when breeding, they do not have a territory or set home. They return year after year to the same breeding place.
The Laysan albatross is carnivore (molluscivore), it eats mainly squid and other aquatic prey including fish, crustaceans, and coelenterates and other invertebrates.
Laysan albatrosses are a monogamous species and they mate for life. They perform elaborate courtship displays, consisting of 25 different postures, including clicking their beaks together, tucking them under their wings, and pointing them at skywards at the same time as their mate. Such a display is only performed by first time breeders or non-breeding birds. The breeding season begins in November. These birds breed in colonies, which are sometimes large. Both adults build the nest, a shallow depression in sand. A single egg is laid, which is whitish with brown spots. Both adults incubate the egg during a 65-day period, 3 weeks at a time, and both feed the hatchling. When hunting for food, they leave the chick on its own for several days. Chicks fledge at about 165 days old. Once it leaves the nest and heads out to sea, a Laysan albatross stays at sea for 3-5 years, after which it returns to the nesting colony to search for a mate. They start breeding at the age of 8 to 9 years.
The main threats to this species are commercial fishing, sea-level rise and the swallowing of plastic debris, which is commonly mistaken as food and often blocks and damages the bird’s digestive system, which can cause starvation and death. Eggs and birds on the Hawaiian Islands are removed from airfields in order to discourage nesting there. Introduced predators on land and lead poisoning also kill albatrosses.
According to IUCN’s Red List, the Laysan albatross population size totals around 591,000 breeding pairs, which is 1.18 million mature individuals, and is likely to equate to a total of at least 1.7 million individuals. The U.S. Fish and Wildlife Service estimated the total worldwide population for breeding pairs in 2003-2004 as 630,000 pairs. The biggest colonies are on Midway Island (441,000 pairs) and Laysan Island (145,000 pairs). Overall, currently Laysan albatrosses are classified as Near Threatened (NT) on the IUCN Red List, but their numbers today remain stable.
Laysan albatrosses, aside from preying on squid and fish and controlling their population, may also affect predator populations (tiger sharks and rats), as items of prey.
