WeBS is a UK-wide monitoring scheme which targets wildfowl, waders and other waterbirds to produce population abundance and distribution trends and determine important sites for waterbirds in the UK.
Background
WeBS is a partnership between the British Trust for Ornithology (BTO), Royal Society for the Protection of Birds (RSPB) and JNCC. JNCC jointly provides funding alongside BTO and RSPB and sits on the steering group to help direct scheme developments.
Waterbird monitoring is one of the longest running coordinated biological surveys in the UK, going back to 1947 in its original form. Since then, it has undergone a series of changes before emerging as the current WeBS in 1993.
WeBS would not be possible without the dedication and support of thousands of talented volunteers. In the 2022/2023 season, there were 3,801 registered volunteers who made 43,640 visits to 3,325 core sites and additional visits to 19 estuaries. There are over 13 million species observations stored in the WeBS database across all survey types. Using the Heritage Lottery Foundation figures, the time volunteers dedicated to WeBS in the 2021/2022 season was valued at nearly £4,500,000.
Why do we monitor wetland birds?
The UK is of international importance for global waterbird populations due to its large areas of wetlands and mild winter climate, making it an important part of the migration route and/or wintering grounds of many Arctic-nesting waterbirds. The UK joined the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) in 1999 which uses coordinated international effort to protect migratory waterbirds and their habitats. To fulfil these commitments, the UK must identify, monitor, protect and manage sites of particular importance to waterbirds, objectives which WeBS contributes greatly towards.
The data produced by WeBS surveys are used to create population abundance and distribution trends and identify sites which are important for wetland birds. This information is important for local, national and international conservation monitoring and management by identifying populations which are declining (and thus in need of more targeted conservation) and populations that are stable or increasing (populations that may have undergone successful conservation measures). As the UK and Ireland are on the western-most fringes of the range of many of these birds, monitoring the birds here is of great importance as these locations will often be the first to experience changes in migratory patterns and behaviours. Monitoring these populations therefore reveals early signs of change where conservation action may be required at local and larger scales.
WeBS data are used at a site level as both evidence for designating sites (e.g. the extension of Cotswold Water Park Sites of Special Scientific Interest (SSSI)) and for site condition assessment of Special Protection Areas (SPAs) and SSSIs through the WeBS Alerts periodic report.
WeBS is also important for national and international monitoring. Data and trends from the core counts contribute to JNCC Official Statistics and UK Biodiversity Indicators C4a and C5 and the Scottish Wintering Waterbird Indicator. WeBS data also contribute to the International Waterbird Census which monitors waterfowl populations across the African-Eurasian migration paths.
In addition to the core counts that make up the bulk of the data, low tide counts provide detailed information on the feeding distribution of waterbirds in estuarine habitats. These data are useful for site specific management decisions to increase protection in areas where it is required in response to human activities. For example, WeBS data were an important part of preventing the development of a deep-water container terminal on Southampton Water. Low tide data also help further understanding of how sea level changes may affect our wetland bird species.
Sampling approach/how are the data collected?
WeBS consists of two surveys: core counts (which are mainly high tide counts of roosting birds) and low tide counts which help to identify key foraging areas in the intertidal zone.
The core counts that take place every year are used to produce population indices and trends and site level monitoring of protected and other wetland sites. They consist in coordinated monthly counts across both coastal and inland wetland habitat sites across the UK, primarily during the winter months of September to March, although counting does go on all round the year. Core counts are carried out according to ‘look-see’ methods, where a trained observer surveys the whole area of a predefined site and records the number of all waterbirds (gulls and terns are optional) that they can see at the same time.
Low tide counts aim to supplement the core counts by providing information on intertidal feeding in UK estuaries. Low tide counts also follow ‘look-see’ methods, adhering to designated SPA site boundaries. The counts do not occur on coordinated dates, but each section of an estuary is counted monthly between November and February for two hours either side of low tide. A number of UK estuaries are surveyed each year, with the aim to cover all major estuaries at least once in every six years, although some are surveyed more frequently than this.
How and where data/results are available to stakeholders
Each year, an annual report is published on BTO’s website which outlines species trends, peak counts and site summary data. The dataset can also be explored in greater detail via the interactive WeBS report online. More detailed datasets can be obtained from the WeBS data request service.
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