Press release 2010/01 - Issued by the Centre for Ecology & Hydrology


A recent increase in winter mortality in Atlantic puffins could be due to worsening conditions within the North Sea, according to new findings published in the scientific journal Marine Biology. The study used geolocation technology to track puffins from the Isle of May National Nature Reserve, home to the largest colony of puffins in the North Sea. The puffin population on the Isle of May has declined by 30% in recent years.

The research team included scientists from the Centre for Ecology & Hydrology and the British Antarctic Survey and was led by Professor Mike Harris, Emeritus Research Fellow at the Centre for Ecology & Hydrology, who has studied puffins for 37 years.

Professor Harris said, “Modern technology has come to the aid of the puffin just when it was needed. The quarter of a million puffins that breed in northeast Britain head out to sea during the winter and we previously thought that they stayed in the North Sea. We now know that some make long trips into the Atlantic during winter. This is vital new knowledge which should help us explain recent declines in puffin numbers.”

Recently-developed miniature logging devices weighing 1.5g were deployed during the 2007/2008 winter on 50 puffins from the Isle of May National Nature Reserve.  Data was downloaded from thirteen of these geolocators with the records showing that over three-quarters of the birds made excursions lasting between one and four months into the Atlantic between successive breeding seasons, before returning to their home waters in the North Sea.

Previous studies have shown that puffin numbers at the two largest colonies on the east coast of Britain declined by 30% between 2003 and 2008 following rapid population increase over the previous 40 years. Further counts in 2009 confirmed this decrease and also recorded a decrease at two other colonies.  Most seabird mortality occurs during the winter when food abundance is depressed, weather conditions are poor and shorter days restrict foraging opportunities.

Since there was an unprecedented mortality of adult puffins over the 2007/2008 winter, the logger results suggest that conditions in the North Sea may have become less favourable for puffins in recent years, particularly during autumn and early winter, forcing many birds to move into the Atlantic.  Here they have to travel greater distances and adapt to different habitats.

Co-author Dr Francis Daunt from the Centre for Ecology & Hydrology said, “Although the factors causing the recent changes in puffin distribution and mortality require further study we are confident that this new approach, combining data from logging devices such as geolocators together with other information on changing conditions in the North Sea, will help improve our understanding of this complex ecological issue.”

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Notes for editors

For further information and interview opportunities contact Barnaby Smith. Press Officer, Centre for Ecology & Hydrology. Telephone +44 (0) 7920 295 384 or email

The research is published online in the journal Marine Biology. The paper reference is:

Michael P. Harris, Francis Daunt, Mark Newell, Richard A. Phillips and Sarah Wanless (2009) Wintering areas of adult Atlantic puffins Fratercula arctica from a North Sea colony as revealed by geolocation technology. Marine Biology DOI 10.1007/s00227-009-1365-0

The Isle of May National Nature Reserve is situated off the coast of east Fife in south-east Scotland. It is a rocky island, about two km long and 400 m wide. It is managed by Scottish Natural Heritage, the Scottish Government's advisor on all aspects of nature and landscape across Scotland. The island is home to about 40,000 pairs of Atlantic puffins, as well as common guillemots, razorbills, black-legged kittiwakes, European shags, Atlantic puffins, herring gulls and lesser black-backed gulls. The resident puffin population attracts many thousands of visitors each year. .

The Centre for Ecology & Hydrology (CEH) is the UK's Centre of Excellence for integrated research in the land and freshwater ecosystems and their interaction with the atmosphere. CEH is part of the Natural Environment Research Council and employs more than 450 people at five major sites in England, Scotland and Wales with an overall budget of about £35m. CEH also hosts more than 150 PhD students. CEH tackles complex environmental challenges to deliver practicable solutions so that future generations can benefit from a rich and healthy environment.

British Antarctic Survey (BAS) pioneered the development of miniaturised loggers for tracking large-scale movements and fine-detail activity patterns of seals, terrestrial birds and, particularly, seabirds. The loggers record light, salt-water immersion and, in the larger models, temperature (used to improve latitude estimation during the equinoxes). Sunrise and sunset transition times derived from the light data are used to determine location twice per day using astronomical algorithms, and in marine species, the immersion data indicates when the bird is flying compared with on the sea surface.  BAS loggers are used in >90% of tracking studies world-wide of nonbreeding seabirds, and a smaller number of studies of breeding seabirds that are too small to track using other means. They have provided numerous insights into habitat use, migratory connectivity, variation in distribution related to individual/sex/age/breeding status etc. and, particularly of importance for albatrosses and petrels that are threatened with extinction, on spatial and temporal overlap with fisheries.

The Natural Environment Research Council funded this study. Scottish Natural Heritage supplied permission for the authors to work on the Isle of May National Nature Reserve and the British Trust for Ornithology supplied the recoveries from their Ringing Scheme that is funded by a partnership of the British Trust for Ornithology, the Joint Nature Conservation Committee (on behalf of Natural England, Scottish Natural Heritage and the Countryside Council for Wales, and also on behalf of the Council for Nature Conservation and the Countryside in Northern Ireland), The National Parks and Wildlife Service