The 2003/04-2005/06 Winter Gull Roost Survey (WinGS)

July 2006 Update

Data collection for the 2003/04-2005/06 Winter Gull Roost Survey was completed this January.

Coming shortly after Seabird 2000, the latest review of breeding seabirds in Britain and Ireland (Mitchell et al. 2004), this survey will provide a good overview of the current status of wintering gulls in the UK.

Background

The BTO has organised national surveys of winter gull roosts each decade since 1953 in order to estimate numbers of wintering gulls. The last survey took place in January 1993, during which over 2.5 million gulls were counted in Great Britain. A further 19,000 gulls were also counted in Northern Ireland, 3,850 in the Isle of Man and 8,500 in the Channel Islands. (The results of these surveys are summarised in a British Birds paper – go to the following to see the abstract of this: http://www.bto.org/research/services/publications_abstracts/2003/wint_gull_roost.htm ). Previous surveys have concentrated on known inland sites, with coastal sites first covered during the 1983 survey.

The 2003/04-2005/06 survey was the first since 1993 and covered three winters.

Aims and methods

The first part of the 2003/04-2005/06 survey, undertaken in January 2004, targeted the most important known roost sites across Great Britain and Northern Ireland, both at inland waterbodies and on the coast. Results from the counts at these Key Sites (and some additional sites surveyed) have been used to index gull numbers over the last 50 years and the results of this analysis will be reported in an upcoming paper..

As well as looking at population change, the Winter Gull Roost Survey also aims to produce the first total non-breeding population estimates for the five main gull species that winter in the UK: Black-headed Gull, Common Gull, Lesser Black-backed Gull, Herring Gull and Great Black-backed Gull. To be able to do this it is also necessary to estimate the numbers of gulls away from the Key Sites. Data for this element of the survey were collected by surveying sample Randomly Selected Tetrads inland and also Randomly Selected Stretches of Coast for roosting gulls. These were primarily surveyed in January 2005 and January 2006.

In total, the survey aimed to cover 484 Key Sites, 701 tetrads and 933 random coastal stretches.

Final results

Winter population estimates of Black-headed Gull, Common Gull, Lesser Black-backed Gull, Herring Gull and Great Black-backed Gull for the UK and its constituent countries will be produced in a BTO Research Report to be published later this year; from these results we will also recommend new 1% thresholds for assessing the national importance of sites for the species. A summary paper and BTO News article reporting the new population estimates will follow.

We wish to thank all those who have taken part in the survey for all their efforts.

Data from the 2003/04-2005/06 survey will be available after the publication of the results; data from earlier surveys are already available. If you have any queries about the survey, please contact Niall Burton at BTO Thetford: email: or telephone: 01842 750050.

WinGS was funded by the Countryside Council for Wales, English Nature, the Joint Nature Conservation Committee, the Environment and Heritage Service in Northern Ireland, Northumbrian Water and Scottish Natural Heritage.

Mitchell, P.I., Newton, S.F., Ratcliffe, N. & Dunn, T.E. (2004) Seabird Populations of Britain & Ireland. T. & A.D. Poyser, London. http://www.jncc.gov.uk/page-1548