The GSMP is dedicated to monitoring selected goose and swan populations in the UK. Of the 14 major native goose and migratory swan populations in the UK, the GSMP monitors the abundance, breeding success and distribution of 13 of them during the non-breeding season.
Background
The GSMP is a partnership between JNCC, British Trust for Ornithology (BTO) and NatureScot. JNCC has been involved with GSMP since it was established, and is one of the core funding bodies helping to steer and promote the project and the data it provides.
There is a long history of waterbird monitoring in the UK. GSMP emerged as a separate monitoring scheme in 1993 as a result of major restructuring of waterbird monitoring.
GSMP would not be possible without the dedication and support of hundreds of talented volunteers. During the 2022/2023 season, over 1,000 surveys were carried out by volunteers. Using the Heritage Lottery Foundation figures, the time volunteers dedicated to GSMP in the 2021/2022 season was valued at at least £70,000, with the true value likely being considerably higher.
Why do we monitor geese and swans?
The UK is home to 14 native goose and migratory swan species, many of which are Red or Amber Listed and so the UK has an international responsibility to ensure that conservation and monitoring measures are put in place to protect them. The UK has particular responsibilities towards seven of these species for which the majority of the global population over-winters in or migrates through the UK, relying on the UK’s internationally important wetlands during the non-breeding season. The GSMP monitoring data on abundance, breeding success and spatial range contributes to important conservation and management decisions.
The species covered by GSMP are all migratory, and when wintering in the UK, the birds tend to concentrate in large numbers in a fairly small number of sites to roost, but feed over wide areas during the day. As this kind of behaviour is not ideally monitored by WeBS daytime counts, and as a complete population count is usually feasible, a separate monitoring scheme was devised for these species.
The GSMP data feed into both national and international reporting and provide essential data for site-specific targeted conservation to protect these species and the habitats that they depend on. Nationally, the data contribute to the JNCC official statistic on wintering waterbirds and UK Biodiversity Indicators C4a and C5.
The data also contribute to international datasets and monitoring schemes, such as the International Swan Census, and are used to fulfil commitments to international agreements such as the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA).
Sampling approach/how are the data collected?
The GSMP uses a range of species-specific surveys to monitor populations’ abundance and, when possible, carry out age assessments.
Age assessments estimate the breeding success of a population by counting (1) the number of first winter young birds in a non-breeding flock, and (2) the average number of young in each family unit. The timing of migration and moulting of young birds differs in different species and populations, therefore the timing of surveys must also differ. Identifying a first winter bird can be challenging, so surveyors must be confident in bird identification to take part and age assessments may not always be possible.
Census surveys are carried out at a time of the year when the numbers peak and the birds are most concentrated, and aim to have as complete coverage of the sites as feasible. The surveys are co-ordinated and carried out during specific weekends to minimise double-counting or missing significant numbers of birds, and aim to achieve total population counts, not an index of abundance. The surveys are carried out either at dawn when the birds leave their roosting sites or at dusk as they are flying to the roosts.
The GSMP also contributes to the International Swan Census once every five years, which focuses on Whooper and Bewick's Swans. This survey covers many locations that are not usually covered by annual schemes, particularly non-wetland and temporally flooded sites, to achieve a more comprehensive assessment. These surveys provide estimates for swan abundance, distribution, habitat use and breeding success (through age assessments).
How and where data/results are available to stakeholders
Data from the GSMP are fed into the Wetland Bird Survey (WeBS) database and the Waterbirds in the UK annual report which can be found on the BTO publication page.
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