Wading Birds Feeling the Strain
…on England’s estuaries
Multitudes of wintering birds on an estuary form one of the most magical wildlife spectacles each winter in the UK, but this scene is changing. Data on these birds is collected by thousands of Wetland Bird Survey (WeBS) volunteers at wetlands of all sizes and habitat types, including some of global conservation importance for waterbirds such as the Wash, Morecambe Bay and the Thames Estuary.
Latest results show that populations of England’s most familiar coastal waders have declined markedly in the last ten years. Ringed Plover (-41%), Redshank (-23%), Dunlin (-22%), Curlew (-14%) and Oystercatcher (-13%) are among the eight most abundant waders on England’s estuaries in winter, yet the populations of all of them are declining.
Waders with falling winter populations in the UK include Knot, Bar-tailed Godwit, Oystercatcher, Curlew, Grey Plover, Dunlin, Redshank & Ringed Plover
Millions of waterbirds overwinter on England’s wetlands, many of which use estuaries to take advantage of the rich food supplies they provide. Many of these sites are Ramsar Sites and are legally protected, and WeBS volunteers help undertake a ‘bird health check’ of these and many other sites by counting these internationally important concentrations of wintering waders, ducks, geese, swans and other waterbirds.
The annual WeBS report, now published in conjunction with an online interactive interface, makes this information available to anyone with an interest in birds and the environment. The new report, covering the period up to June 2013, highlights worrying trends shown by the eight most abundant waders on England’s estuaries, particularly in the most recent ten year period.
Precise reasons why these bird populations are changing are not fully understood, but are likely to be due to a combination of factors. Research looking at waterbird counts from across northwest Europe showed that distributions of wintering waterbirds have shifted in recent decades in response to milder winter temperatures. Also, winter population declines noted in the UK may be evidence that fewer young waders are being produced in the Arctic. Improved information is therefore needed on productivity of waders in breeding areas.
Chas Holt, WeBS Coordinator at BTO, said: “In 2012/13, WeBS volunteers made over 34,000 visits to wetland sites to count waterbirds. This is a superb effort and has provided the vital information to show that our internationally important wintering waterbird populations are declining. Research and close collaboration with international counterparts is necessary to understand the reasons why.”
Deborah Procter, Senior Monitoring Ecologist at JNCC said: "Wetland Bird Survey data are used in a wide range of UK conservation activities and contribute to international conservation assessments which help fulfill UK requirements under several international conservation treaties. WeBS trend data were used last year to enable us to report UK implementation of the Birds Directive. Understanding what drives the population changes shown by examination of WeBS data is an on-going challenge."
Richard Hearn, Head of Species Monitoring at WWT added: “The declines in waders and other wintering waterbirds in the UK over the past decade or more, as revealed by WeBS, are indicative of wider concerns about the state of our environment. They demonstrate the unprecedented period of change that these waterbirds are undergoing, and highlight the need for a step change in conservation action if we are to avert continued biodiversity loss.”
Phil Grice, Senior Environmental Specialist, Ornithology, at Natural England said: “WeBS counts not only monitor changes in our wetland birds at national level, but also play a critical role in the designation and subsequent management of many of England’s protected sites, including Sites of Special Scientific Interest (SSSIs), Special Protection Areas and Ramsar sites. WeBS data, can tell us which parts of a site may be at risk from potentially damaging changes in land use or management, and can also act as a ‘health check’ on the site’s overall condition.”
Chas Holt WeBS Coordinator at BTO
30th July 2014