Scientist spends 40 years studying Skomer Island’s seabirds26/06/2012 17:00:27 Guillemots on Skomer Island
June 2012. A bird expert at the University of Sheffield has spent 40 years studying seabirds on an island off the UK in one of the longest running investigations of its kind. Professor Tim Birkhead, of the University's Department of Animal and Plant Sciences, first visited Skomer Island - situated off the cost of west Wales - in 1972 and since then he has returned every summer, gaining invaluable information about guillemots.
Professor Birkhead said: "It has been an invaluable investigation, for example it is clear that climate change has had a huge effect on the guillemots as they now breed two weeks earlier than they did in the 1970s. We also know a huge amount more about guillemot biology than we did 40 years ago, and we can use changes in guillemot numbers to tell us what is happening in the seas surrounding the island.
"Long term studies like this are few and far between but remain vital for understanding changes taking place in the environment. It's been a constant challenge both to secure funding and to carry out the work itself as the birds breed on the sea battered cliffs of a remote island."
½ million seabirds
Technological advances throughout the four decades have enabled Professor Birkhead to gain even more information about the birds.Geolocators
He added: "Using new tracking technologies, like GPS and geolocators, we now have a very complete picture of where guillemots go to forage. During the breeding season they forage within about 60 km of Skomer in the south Irish Sea, but in winter they travel huge distances moving between the Bay of Biscay and the far north of Scotland.
Vast drop in numbers 1940 - 1970
During the early stages of the pioneering study, Professor Birkhead came up with innovative ways to overcome the many technical challenges he faced. In 1972 no one knew how to conduct a census of guillemots as it had never been tried before.
The second task was to determine how many chicks were produced each year and whether it was enough. By marking birds individually with colour rings Professor Birkhead was able to measure their breeding success, see how old they are when they first start to breed and see how long the birds live.