Signs of dramatic changes for some wetland birds, including the Mallard, are reported today as some species reach their highest and lowest recorded population levels in the UK in winter.
Millions of wildfowl and waders escaping the Arctic winter in northern Europe, Siberia, Greenland and Canada, head for our shores, making the UK one of the most important European countries for wintering waterbirds. However, there are signs of dramatic changes for some wetland birds with a few reaching their highest and lowest population levels in the UK in winter.
The latest population figures on wetland birds – and a host of other species are – contained in the State of the UK’s Birds 2011 report – published by a coalition of conservation organisations. The report provides a ‘one-stop-shop’ for the results of bird surveys and monitoring schemes and projects from across the UK from as recently as 2010.
Overall, numbers of wintering waterbirds have been in shallow decline since the late 1990s, but the underlying story is more complex.
One of the greatest losses recorded in the report has been the Mallard – Britain’s most familiar duck – which has hit a new low with the lowest recorded numbers wintering at their most important UK strongholds. The State of the UK’s Birds 2011 report shows that winter Mallard numbers have declined by 38% since 1982 and by 22% since 1998. Conversely, Shovelers have increased by 27% since 1998.
The Whooper Swan, which breeds in Iceland, has reached its highest levels (increasing by 122% in the last 10 years) while the Bewick’s Swan, which breeds in Siberia, has declined by 44% over the same period.
The reasons for the changes are complex and not yet fully understood. Results from waterbird monitoring schemes in other parts of Europe have shown that some changes are likely to be explained by some birds not migrating as far because of milder conditions elsewhere: a phenomenon known as ‘short-stopping’. But for other species, such as the Bewick’s Swan, international cooperation has proven that numbers are declining across northern Europe.
Martin Harper, the RSPB’s conservation director, said: ‘The UK has some of the best sites in the world for wetland birds and the sight and sounds of tens of thousands of birds wheeling around these wetlands ranks among the best natural history experiences that our islands have to offer.
‘Although the numbers of birds visiting these sites may fluctuate, they are vital and must continue to be protected. But the spectre of development, for example from ports and airports, continue to haunt some of our most important sites.’
Other species which have declined since 1998 are: Pochard (-46%); Dunlin (-39%); Bar-tailed Godwit (-29%); and Ringed Plover (-26%).
In contrast, the report also shows that some wintering wetland birds have increased in the UK since 1998, including: Avocet (+95%); Black-tailed Godwit (+53%); and Pink-footed Goose (+27%). The Avocet and Pink-footed Goose have both reached their highest population levels since records began.
Neil Calbrade, WeBS Research Ecologist at the BTO, said: ‘This shows the value of continued monitoring of wetland sites through long-running schemes such as the Wetland Bird Survey (WeBS). For more than 60 years, WeBS counters have carried out monthly surveys of over one and a half million birds annually which allows us to build up a picture of the fortunes of these waterbirds and how they may be affected by climate change, habitat loss and development.’
Richard Hearn, Head of Species Monitoring with the WWT, said: ‘We are seeing increasingly rapid changes in wintering waterbird numbers in the UK. Some species such as Goldeneye, are most likely moving elsewhere, but others such as Long-tailed Duck and Velvet Scoter, are thought to be declining everywhere and require urgent conservation action.
‘An icon of the UK migration season, Bewick’s Swans also need continued focus to ensure conservation actions are implemented. And with so many of these migratory birds reliant on our wetlands, the loss of 45% of wetland habitat in the UK in the last 75 years is a major concern.’
Phil Grice, Natural England’s senior ornithologist and one of the report’s authors added; ‘The production of robust evidence on the numbers and movements of birds, is vital in ensuring their long term survival in a changing world. This report supports important conservation efforts which protect significant waterbird populations and their habitats throughout the year and provides an ongoing health check on the status and trends of key species.’
David Stroud, Senior Ornithologist at JNCC, added: ‘Forty years ago, governments agreed the Ramsar Convention on wetlands as an international treaty to stem the loss of the wetlands so critical to waterbirds and other wildlife. Many of the most important of the UK’s wetlands have since been designated as Ramsar Sites, but the report highlights some of the critically important sites in our Overseas Territories and Crown Dependencies that remain unprotected.’
The State of the UK’s Birds 2011 report is produced by a coalition of three NGOs – RSPB, British Trust for Ornithology (BTO), and the Wildfowl & Wetlands Trust – and the UK Government’s statutory nature conservation agencies – the Countryside Council for Wales (CCW), Natural England (NE), Northern Ireland Environment Agency (NIEA), Scottish Natural Heritage (SNH), and the Joint Nature Conservation Committee. (JNCC).