17 July 2014

New BTO project initiated - Gull Positioning System (GPS)

This summer, 50 Lesser Black-backed Gulls breeding on Skokholm Island, Pembrokeshire and Walney Island, Cumbria have been kitted out with state-of-the-art GPS tags by scientists from the BTO as part of a project funded by the Department of Energy and Climate Change, studying how these birds might use areas of the marine environment earmarked for the development of offshore wind turbines, as well as areas where wind farms already exist.

The Lesser Black-backed Gull was classed as “Amber” in the most recent Birds of Conservation Concern and is declining at a number of breeding colonies where it is protected, included Skokholm and Walney. These tags gather high quality information that is already providing valuable insights into the habitats these birds use, which could be used to improve their conservation and management.

Lesser Black-backed Gulls breeding on Skokholm Island, photograph by Richard Brown

The birds were tagged in May, at which time they were incubating eggs and we are now receiving regular updates on where they have been, the altitude they are flying at and how long they spend in certain areas. Initially almost all birds from Skokholm went inland every day to feed, visiting reservoirs and agricultural areas throughout Pembrokeshire and Carmarthenshire, as well as towns like Milford Haven and Pembroke. However, once their chicks started hatching towards the end of May, birds began to fly out to sea, suggesting these gulls were seeking high quality fresh fish for their youngsters. Recently, one female travelled as far as the Isles of Scilly before returning to her nest site, while another bird visited Great Saltee Island off the coast of Ireland.

A Lesser Black-backed Gull breeding on Skokholm makes a day trip to Ireland

Lesser Black-backed Gulls tagged on Walney Island have spent time in Barrow and other local urban areas, where gulls are not always popular. However, many birds have flown straight over these locations on their way to parts of the Lake District, while others have journeyed far out into the Irish Sea. Birds that do visit towns have tended to favour destinations like Blackpool, while others have made day trips as far afield as Warrington.

You can see where our birds have been going for yourselves if you keep an eye on these pages hosted by researchers at the University of Amsterdam, who made our gulls’ tags:



This project would not have been possible without the help of Skokholm Wardens Richard Brown and Giselle Eagle, and Matt Lipton, Warden at South Walney.

For more information on this BTO project and to watch our gulls on the BBC One Show click here


  1. Interesting - I've just yesterday been reading about the Gull Positioning System work they've been doing in Belgium where they found exactly the same thing regarding foraging locations before and after chicks hatched. They've done some interesting data visualisations too!

  2. fascinating subject. It makes ring-readers' efforts reading colour rings on LBBs rather second class though. Not too worried it was too hot to do my weekly landfill site session now!

    1. The GPS loggers provide a lot of fascinating results, it enabels us to answer a huge number of long unanswered questions. Nevertheless systematic bird ringing remains essential, e. g. for an integratede monitoring of bird populations, studying population processes

  3. Interesting - prompts the question do inland rooftop nesting LBBGs in cities such as Birmingham go to the coast for frsh fish?

  4. Kees Camphuysen

    A message for Steve Lister...NO, ring-reading is by no means second class, it simply answers very different questions. Aspects like annual survival, for the moment also movements by young birds, pair bond, all soorts of behaviour aspects...not to mention sample size in comparison with tagged birds, make colour-ring reading a very useful activity throughout