Mar 21

Scientists have confirmed that the world’s rarest albatross, the Amsterdam albatross (Diomedea amsterdamensis), is indeed a separate species, ending 20 years of debate on the status of this Critically Endangered bird.

Photo of Amsterdam albatross displaying

This marine albatross spends the majority of its life out at sea, coming to land only to breed.

Genetic analysis 

The Amsterdam albatross is named after Amsterdam Island in the Indian Ocean, the only place in the world where this species breeds. It was first described in 1983, but the scientific community has since been divided over whether it is a separate species or a subspecies of the wandering albatross (Diomedea exulans), which also inhabits the Southern Ocean. 

A team of Canadian researchers aimed to resolve this debate by examining the Amsterdam albatross’ DNA. The study, which is published in the Journal of Avian Biology, revealed significant differences between this species’ DNA and that of the wandering albatross, proving that these close relatives are indeed separate species. 

The genetic analysis also showed that the Amsterdam albatross separated from the wandering albatross as long as 265,000 years ago.

Photo of Amsterdam albatross sitting on nest

Nesting occurs on a highland plateau, at 470 to 640 metres, in an area of peat bog that has an ample covering of moss.

Geographic isolation 

Dr Theresa Burg from the University of Lethbridge, Canada, one of the report’s authors, explained how the Amsterdam albatross differs in appearance from the wandering albatross.  

“They are slightly smaller in size” she said. “They lay their eggs at a different time and have slightly browner plumage than the other wandering albatrosses.” 

The report’s authors suggest that this species’ isolation from other albatrosses on the remote, volcanic Amsterdam Island, where it is the only breeding albatross, possibly led to its separation and development as a unique species.

Photo of Amsterdam albatross chick in nesting habitat

Although the population is currently stable, its small size and existence on just a single island means the Amsterdam albatross has a precarious status.

A Critically Endangered species 

With only around 170 individuals remaining, and just 18 to 26 pairs breeding annually, it is hoped that efforts to conserve the Amsterdam albatross will be increased. 

Grazing by livestock on Amsterdam Island, predation by introduced mammals and accidental entanglement in long-line fishing gear have all imperilled this species, which is listed as Critically Endangered on the IUCN Red List

“This is one additional, but important, piece of evidence that hopefully can help protect the remaining Amsterdam albatrosses” said Dr Burg. 

View 20 photos of the Amsterdam albatross on ARKive.

Read the study at the Journal of Avian Biology.

Alex Royan, ARKive Species Text Author