Scientists from the British Trust for Ornithology (BTO) are working with the National Trust, using GPS technology to gain fascinating insights into the secret lives of gulls breeding at Orford Ness National Nature Reserve in Suffolk.
During 2010 and 2011, 25 adult Lesser Black-backed Gulls were fitted with state-of-the-art solar powered GPS tags that give unprecedented detail on these birds’ location, altitude and acceleration. This project is funded by the Department of Energy and Climate Change to investigate how gulls might interact with offshore wind farms, but these long-lasting tags are also revealing all sorts of interesting and unexpected data about this migratory species’ movements throughout the year.
The information stored on the tags downloads automatically once birds are within a few kilometres of a mast at the Orford Ness nature reserve. Birds are now returning to the 10-mile long shingle spit to breed, so their overwinter movements are only just being unveiled. Last year all tagged birds migrated to Spain, Portugal and Morocco, but this year their behaviour has been very different, with some birds remaining in the UK, and one not even leaving East Anglia!
These contrasting patterns are beautifully illustrated by the project’s only tagged breeding pair. The male spent most of his winter in Dorset, Hampshire and Somerset, primarily roosting in and around Poole Harbour. His mate, meanwhile, opted to sun herself in Lisbon. Intriguingly, these birds, that left Orford Ness in late summer, nearly met in late October, when the female was preparing to depart for warmer climes. On the afternoon of 28th, the female called in on Ibsley Water in Hampshire for about half an hour. Less than an hour later, the male was also there, having returned to roost after spending the afternoon on nearby fields. However, the female had already left and was on her way south, missing a reunion with her mate by a matter of minutes!
Dr Viola Ross-Smith, Research Ecologist for the BTO, said, “Spring is the most exciting time of year to be involved with this fantastic project. We spend all autumn and winter wondering what our birds are up to, so it’s brilliant to see them check in to our system again and find out where they’ve been”.
Like other UK-breeding gulls, the Lesser Black-backed Gull is in decline. The information gathered by this project should prove invaluable in helping the National Trust and the BTO understand the conservation needs of the Orford Ness breeding colony, and of gulls more generally.
Duncan Kent, the National Trust’s Warden for Orford Ness, said, “Orford Ness is an internationally important nature reserve due to the rare and fragile vegetated shingle found on site, and it provides the Lesser Black-backed Gull with a safe environment during the breeding season. Despite this, our colony is declining. We hope data gathered from this exciting project will help us understand why and enable us to identify the actions needed to reverse the decline.”