Twenty-four species of albatrosses roam the world's oceans south of 30°S and north of 30°N, for these are the windiest latitudes and albatrosses need the wind to fly. They are members of the family of petrels, or 'tube noses' - although no-one is really sure what purpose the tubes that line each side of their bill actually serve.

They vary in size, with the largest being the Wandering Albatross, which has a wing span of around 3.5 metres (the greatest of any bird) and a head the size of a child's. Their flying abilities are legendary - soaring effortlessly over the world's wildest oceans, and returning to land only to breed.

All species of albatross build nest mounds of earth, mud, moss and grass. These nests are on high, windy slopes necessary for taking off in the prevailing winds. They only lay one egg at each breeding attempt (in October/November), which is incubated by the male for 60 to 90 days. The chicks stay at the nest site for about a year.

The chick is cared for by both parents and is often left for long periods of time while the parents go out to sea looking for food - often for days at a time, covering hundreds of kilometres. Some species live 70 or 80 years.

They're diet consists of squid, small fish and krill. They fly great distances searching for food and migrate up to 30,000 km from their nesting sites.

Seabirds like albatrosses are unable to cope with unnatural levels of mortality because they mature fairly late in life (around 12 years of age for some species) and they only have one young each year or every second year. As well, partners mate for life and if one partner is lost to long-line fishing then it may take many years for the surviving partner to find a new mate and re-commence breeding.

Grey-headed Albatross

Grey-headed albatross (Diomedea chrysostoma) have a 2.2 metre wingspan, a white body, a bluish grey head and neck, and a dark grey back and tail.

They breed on sub-Antarctic islands, mainly in the South Atlantic

Black-brows and Grey-headed albatross have many similarities, and are also known as mollymawks. They often breed together in vast hillside colonies.

Grey-headed albatross generally breed every two years: if a chick is successfully reared in one season, the parents will not breed the next year.

Their lifespan is at least 36 years.

Black-browed albatross

Black-browed albatross (Diomedea melanophrys) are mostly white with yellowish-orange webbed feet, grey highlights and a bright yellow beak. A conspicuous black eyebrow gives them their name.

Even though the Black-brows are one of the smallest alabatross species, an adult bird is still 80-95cm in length, with a wing span of 210-250cm and weighs three to five kilos. Black-browed albatross can live for 30 years or more, and have a strong bond to their colony of birth.

They are found over Antarctic, Subantarctic and sub-tropical waters and breed on Sub Antarctic and Antarctic islands. Eighty-five percent of the global population of black-browed albatross (estimated at 680 000 pairs), nest in the Falkland Islands.

Satellite tracking work with albatrosses over three seasons at Diego Ramirez reveals that black-browed albatrosses forage from 57oS to about 39oS over the narrow (10-15 mile wide) continental shelf, whereas grey-headed albatrosses forage just off the continental shelf over a huge area of the south-east Pacific Ocean, including deep into Antarctic waters (67oS) and nearly half way to New Zealand.

Wandering Albatross

Wandering albatross ( Diomedea exulans ) are the largest of the albatrosses and have a white head, neck and body, a wedge-shaped tail, and a large pink beak. Juveniles have mostly dark plumage, which gradually whitens with age.

Wandering albatross are found right across the Southern Ocean, including Antarctic, subantarctic and subtropical waters.

They breed only once every two years, on Sub-Antarctic and Antarctic islands between 46° and 56°S such as Iles Kerguelen, South Georgia and Macquarie Island.

With chicks consuming up to 100kg of food during their rearing period, - which lasts for approximately 300 days - the task of incubating the half-kilogram egg and rearing the chick is shared by both parents.

Foraging trips of wandering albatross can last for 50 days at a time but tend to be much shorter during the breeding season. Young birds will remain at sea for 5 to 10 years before returning to their natal island to breed.

Research shows that decreasing populations are due to the birds being caught in long-line fishing operations.