They are famed for their massive wingspans, their longevity and their life-long companionship – now it appears that wandering albatrosses have another distinctive characteristic.
Researchers have discovered that, despite a general decline in old age, these remarkable seabirds are more likely to successfully raise a chick when they breed for the last time.
Scientists from the University of Edinburgh and the British Antarctic Survey say that like many animals, wandering albatrosses get better at rearing offspring as they gain experience.
The birds’ ability to provide for their young then declines after a certain age, most likely because older albatrosses become less capable of finding food for their young.
However researchers have found that the albatrosses’ capacity to raise chicks improves again when they have their final chick.
This could be because they increase the effort they put into rearing just before they die – a pattern which is predicted by theory but is rarely seen in wild animals.
The wandering albatross, which has the largest wingspan of any living bird, can live for more than 50 years. They breed on remote sub-Antarctic islands, and once paired, albatrosses usually mate for life.
Females produce only one egg each breeding cycle which both parents take turns to incubate. They then provide food for the chick until it leaves the nest – around one year after the egg was first laid.
Hannah Froy of the Institute of Evolutionary Biology at the University of Edinburgh said: “This improvement in breeding success at the end of life is indicative of what we call ‘terminal investment’, which is rarely documented in vertebrates. By increasing the investment in the last chick, individuals may be able to capitalise on one final opportunity to pass on their genes before they die.”
The 30-year study, which is published online in Ecology Letters, was supported by a George Macdougal Mackintosh Scholarship, the Natural Environment Research Council (NERC) and the Biotechnology and Biological Sciences Research Council (BBSRC).
For more information please contact Eleanor Cowie, Press and PR Officer on Tel: 0131 650 6382 or Email: Eleanor.Cowie@ed.ac.uk