Winter Gull Survey (WinGS)

A survey in 2024 and 2025

The last survey ran from 2003/04 to 2005/06 so this survey is long overdue with previous surveys taking place approximately every ten years since the first such survey in 1952/53.

The project’s overarching aim is to provide updated information on the numbers and distributions of wintering gulls in the UK, with a focus on Black-headed Gull, Common Gull, Lesser Black-backed Gull, Herring Gull and Great Black-backed Gull.

The updated information is important in order to understand how wintering populations of gulls have changed over the last 20 years. Understanding how wintering populations are faring and identifying important wintering sites is vital to help protect these species. Furthermore, gulls have been impacted by the outbreak of Highly Pathogenic Avian Influenza (HPAI) and are among the species that may be a potential vector contributing to the spread of the virus. Hence, information about wintering gull numbers and their distributions will also be helpful in understanding the potential impacts on their and other species’ populations.

You do not need to be a member of the BTO in order to participate in this survey.

Winter plumage Herring Gull, by Liz Cutting / BTO

The Time of Year for the survey

Two specific dates namely 21st January 2024 and 19th January 2025 (although the survey can be a week either side of that date) . In addition to these dates surveyors will be asked to make repeat visits throughout autumn 2024.

What the survey involves

At key sites arriving at the site at least two hours before dusk, identifying and counting any gulls already roosting and then identifying and counting all gulls flying in to roost along flight lines. Entering the data online.

At other sample sites the same methodology is used, but there might not be any water on which gulls can roost as the sample sites have been randomly selected.

What skills are required?

A clear understanding of the identification criteria for the U.K.’s six primary gull species is essential. These species being Common, Black-Headed, Mediterranean, Herring, Lesser Black-Backed and Great Black-Backed Gulls. As more unusual gull species may also be observed broad knowledge is helpful.

Also access to the internet as the results are entered online.

Where are the survey sites in Surrey?

20 sites in the BTO Surrey region have been chosen for this survey. Of these 13 are key inland sites. Six are inland sample sites. The remaining site is called a coastal site as it is the River Thames at Hampton Court (though the river is no longer tidal at that point).

Here is a link to a map showing all the sites in Surrey, where you can request a site to be allocated to you. Alternatively look at this document which shows the sites that still need covering as at 17th January 2024 with comments about access. Also you can go to a list of Winter Gull survey sites in Surrey (see Winter Gull Survey tab). This list shows all the sites and whether vacant or allocated.

If you can help please note it is easier if you have registered for this survey on the BTO website before requesting a site.

Need more information?

If you are interested in participating in this survey or would like more information please contact the Regional Organiser (RO) for this survey. The RO is Penny Williams email