Awesome, Majestic, Declining, Vulnerable… Albatrosses

By Keith Hutton on August 23, 2012 in Other

There have been plenty of whales to see in the bays and off the beaches of the east for the last couple of months as they make their annual migration north. Hump-backed Whales feed in the Antarctic region in summer and return to the warm waters off the east coast of Australia to breed between June and August, when they are often accompanied by seabirds from the Southern Ocean, which come to Australia in winter too. These include cape petrels, giant petrels and whale birds, but it’s the albatrosses that most often attract the attention of people watching migrating whales.

It is convenient to divide albatrosses into three groups. The great albatrosses are the largest marine birds, awesome and majestic with wingspans more than three metres. Adults are recognisable by their huge size, white backs, long dark wings and effortless gliding flight low over the water. The smaller albatrosses all have dark backs and dark wings so they appear uniform in colour from wing tip to wing tip. The two members of the third group, the sooty albatrosses, are entirely brownish grey and they usually stay well out at sea, unlikely to be seen from the shore, even as beach-washed storm victims.

Albatrosses are mainly confined to the southern hemisphere and are more or less circumpolar in distribution. They seldom flap their wings and only land to loaf on the sea in calm weather and to breed on isolated islands. All of the species that inhabit the southern hemisphere have been recorded in Australian waters, but only Shy Albatrosses nest in Australian territory. All albatrosses spend most of their time soaring and skimming easily over the ocean, travelling thousands of miles in search of food. Generally albatrosses eat cephalopods (cuttlefish and squid), fish, crustaceans, galley waste from oceangoing ships, and offal resulting from the operations of fishing boats, in varying proportions depending on species. They normally forage most actively at night when their preferred natural food is near to the surface and easy to access.

The activities of humans have been disastrous for seabirds, which are more vulnerable than any other group of birds. Almost a third of them are globally threatened, and nearly half are experiencing declines in their populations. The commercial fishing industry accounts for hundreds of thousands of seabird deaths every year, dragging several species to the brink of extinction.

Furthermore, albatrosses have extended breeding periods and nest on the ground, usually on islands, when their eggs and chicks are easily accessible to introduced predators, particularly cats, rats and mice. They have also been adversely affected by pollution, and destruction of nesting habitat by grazing sheep and cattle, feral pigs and introduced rabbits.

Despite the global picture appearing gloomy, Australia has had some success in mitigating seabird threats. The by-catch of seabirds in many long-line fisheries is reducing, and removal and eradication of invasive species from islands with important breeding colonies is progressing. Nevertheless, much more remains to be done to reduce the threats to these birds that share the oceans and seas of the world with us, and to reverse the appalling human-induced declines in their populations.