Diomedeidae – Albatrosses

The Diomedeidae or Albatrosses are large seabirds allied to the procellariids (Petrels, Shearwaters, Storm Petrels and Diving Petrels) in the order Procellariiformes (the tubenoses). They range widely in the Southern Ocean and the North Pacific. They are absent from the North Atlantic, although fossil remains show they once occurred there and occasional vagrants are found. Albatrosses are among the largest of flying birds, and the great albatrosses (genus Diomedea) have the largest wingspans of any extant birds, reaching up to 3.7 metres. They are usually regarded as falling into four genera, but there is disagreement over the number of species, with several subspecies showing differences of mitochondrial DNA).

They are highly efficient in the air, using dynamic soaring and slope soaring to cover great distances with little exertion. They feed on squid, fish and krill by either scavenging, surface seizing or diving.

Wandering Albatross Diomedea exulans – ©Bernard Spragg CC0 via Wikimedia Commons

Most albatrosses range in the Southern Hemisphere from Antarctica to Australia, South Africa and South America. The exceptions to this are the four North Pacific albatrosses, of which three occur exclusively in the North Pacific, from Hawaii to Japan, California and Alaska; and one, the waved albatross, breeds in the Galápagos Islands and feeds off the coast of South America. The need for wind to enable gliding is the reason albatrosses are for the most part confined to higher latitudes: being unsuited to sustained flapping flight makes crossing the doldrums extremely difficult. The exception, the Waved Albatross, is able to live in the equatorial waters around the Galápagos Islands because of the cool waters of the Humboldt Current and the resulting winds.

Grey-headed Albatross Thalassarche chrysostoma – ©JJ Harrison via Wikimedia Commons

The albatross diet is predominantly cephalopods, fish, crustaceans, and offal, although they will also scavenge carrion and feed on other zooplankton. Until recently it was thought that albatrosses were predominantly surface feeders, swimming at the surface and snapping up squid and fish pushed to the surface by currents, predators, or death. The deployment of capillary depth recorders, which record the maximum dive depth undertaken by a bird, has shown that while some species, like the Wandering Albatross, do not dive deeper than a metre, some species, like the Light-mantled Albatross, have a mean diving depth of almost 5 m and can dive as deep as 12.5m. In addition to surface feeding and diving, they have also been observed plunge diving from the air to snatch prey.

Antipodean Albatross Diomedea antipodensis – ©JJ Harrison via Wikimedia Commons

Albatrosses are colonial, nesting for the most part on remote oceanic islands, often with several species nesting together. Pair bonds between males and females form over several years, with the use of ‘ritualised dances’, and will last for the life of the pair. A breeding season can take over a year from laying to fledging, with a single egg laid in each breeding attempt.

Laysan Albatross Phoebastria immutabilis – ©Dubi Shapiro

All the southern albatrosses create large nests for their egg, utilising grass, shrubs, soil, peat, and even penguin feathers, whereas the three species in the North Pacific make more rudimentary nests. The waved albatross, on the other hand, makes no nest and will even move its egg around the pair’s territory, as much as 50m, sometimes causing it to lose the egg. In all albatross species, both parents incubate the egg in stints that last between one day and three weeks. Incubation lasts around 70 to 80 days (longer for the larger albatrosses), the longest incubation period of any bird. It can be an energetically demanding process, with the adult losing as much as 83g of body weight a day.

Albatross chicks take a long time to fledge. In the case of the Great Albatrosses, it can take up to 280 days; even for the smaller albatrosses, it takes anywhere between 140 and 170 days.

Albatrosses live much longer than most other birds; they delay breeding for longer and invest more effort into fewer young. Most species survive upwards of 50 years, the oldest recorded being a Northern Royal Albatross that was ringed as an adult and survived for another 51 years, giving it an estimated age of 61. Given that most albatross ringing projects are considerably younger than that, it is thought likely that other species will prove to live at least as long.