The latest annual Wetland Bird Survey (WeBS) statistics, covering the period up to 2022/23 have been released today and show that fewer ducks, geese, swans and wader species are travelling to the UK as northern European winters experience milder conditions.
The UK is host to internationally important numbers of wintering waterbirds, and the long-term monitoring Wetland Bird Survey (WeBS) and Goose and Swan Monitoring Programme (GSMP) provide essential data that informs decision makers when considering conservation measures for these birds.
With data provided by over 3,800 dedicated volunteers across the UK, the surveys deliver an annual assessment of ducks, geese, swans and waders residing on, or passing through, our coasts, estuaries, lakes, reservoirs and rivers.
The 2022/23 WeBS report reveals yet more changes in the fortunes of many of our wildfowl (geese, ducks and swans) and wading birds. As winters continue to become milder and damper across much of northern Europe, many species are altering their behaviours in response. Historically, harsh conditions in northern and eastern Europe would see huge numbers of birds migrating to the relatively mild conditions of a British winter but now, as previously frozen landscapes become increasingly accessible, significant numbers of birds are staying closer to their breeding grounds, in a phenomenon known as short-stopping.
Those that do still make the journey across the North Sea to spend the winter in the UK are often arriving later and leaving earlier, therefore staying with us for much shorter periods.
Although 2022 and 2023 were the two warmest years on record in the UK, the 2022-2023 winter was something of a mixed bag. December 2022 experienced a notable cold snap, followed by a period of milder weather before a short drop once again in mid-January. The rest of the winter period remained mostly mild and settled. As a consequence, there appeared to be little major cold weather-related movement of wildfowl and waders and once again many species remained on the continent.
However, it is not just wildfowl from the north that are undergoing change. The survey has also revealed that other familiar waterbirds such as Coot are being affected by milder winters. The UK Coot population comprises both resident birds which breed here and some birds which join them for the winter. And while research suggests declines in our breeding population, we are also seeing a notable reduction in wintering birds. Coot are not generally considered as migratory but ringing recoveries have demonstrated that they can cover considerable distances. For example, one Coot that was ringed in London in 2017, was spotted in St. Petersburg, Russia, in April 2021, three months after last being seen in London. It was then seen again in London in March 2022, showing that it completed a round trip of 4,000 km!
Not only are we seeing a reduction in birds arriving for the winter but the survey also reveals that some birds which would have left the UK in autumn are now staying, rather than heading to warmer climes. We have seen an increase in the numbers of such species as Black-tailed Godwit, a striking wading bird of freshwater marshes and estuaries, remaining on our shores as opposed to migrating to southern Europe, as they did in the past.
Whilst monitoring reveals short-stopping as a contributor to the observed changes, mostly declines, to our wintering waterbird populations, we must not forget that some of these species, such as Bewick’s Swan, are also experiencing declines in their breeding populations. Continued monitoring here in the UK and international collaboration on flyway scale are essential for tracking future changes in populations and distribution of migratory populations of our waders and wildfowl as they continue to adapt to a changing climate, degraded landscapes and multiple other challenges, so that we may inform future conservation decisions and considerations.
WeBS is a joint project managed by the British Trust for Ornithology (BTO), the Royal Society for the Protection of Birds (RSPB) and the Joint Nature Conservation Committee (JNCC). GSMP is a joint project coordinated by BTO, JNCC, and NatureScot.
The project managers and coordinators are indebted to the thousands of WeBS and GSMP volunteers who give their time and skills to collect the data used in these statistics.
For more information, visit the Wetland Bird Survey (WeBS) Annual Report webpage.