For the first time, a new study has carried out full breeding surveys of Redshanks around North Norfolk and the Outer Humber and revealed positive numbers of the threatened species. Ecologist Graham White, who led the surveys, shares his experiences on the saltmarshes and what this means for conservation.
Having just retired, I took on what turned out to probably be one of the hardest (but certainly enjoyable) jobs I have done – surveying all of the North Norfolk saltmarsh for Redshanks, the iconic spring bird of the muddy marshes. Within the UK, Redshanks breed both on inland habitats (such as wet grassland and uplands) and coastal saltmarsh. However, saltmarsh supports more breeding pairs than any other habitat. In 2011 it was estimated 12,000 pairs of Redshanks breed on saltmarshes in the UK, about 45% of the UK and 8% of the European populations [1]. This makes these habitats truly internationally important for the species.
National surveys of saltmarsh Redshanks were conducted in 1985, 1996 and 2011. Our team of four were tasked with repeating this for the North Norfolk saltmarsh – a total of 2,560ha between Holme and Cley, or a similar size to an average town. However, we soon realised the previous studies had surveyed only small sample areas, totalling just 182ha. This was going to be a much larger task.
How do you survey Redshanks?
Three survey visits to each part of the saltmarsh were required between mid-April and the end of June, a total of 17 days of surveying with three people on each trip. On each survey we needed to walk within 100m of every part of the marsh, record all the Redshanks we saw and note whether they were singing, displaying or alarm calling. With such a large area to cover, this resulted in 20-30,000 steps a day. Just to complicate things, surveys needed to be done in the morning and safe access was only possible a couple of hours either side of low tide….and to further complicate things, the marshes are criss-crossed by multiple muddy creeks that needed jumping into and climbing out of. The mornings were muddy and exhausting, and the afternoons occupied by mapping the Redshanks and calculating the number of pairs.
The weather in April was poor; cold and often wet, but it did improve, and May visits were often glorious with saltmarsh plants beginning to flower, hundreds of Brent Geese still grazing the marshes, spring migratory birds arriving, and Oystercatchers and Whimbrel everywhere. Getting out on the marsh in the early morning feels like being in a real wilderness.
What did we find?
In total, we estimated 597 pairs of Redshanks across the entire area, the first time a full survey has been undertaken. On the Humber estuary our colleagues also recorded 419 breeding pairs. This means these areas on the east coast alone hold 5% of the entire UK population, making them vitally important for Redshanks.
It was refreshing to discover there are still good numbers of Redshanks in East Yorkshire and Norfolk, but the wider picture is unfortunately still one of declines. The most recent RSPB research shows a 53% loss of the breeding population of Redshanks on saltmarshes. When we compared the results collected from the same areas in this survey with the previous surveys, we also saw a decline in the number of pairs per km2 , but with varying factors between the surveys influencing this.
Sea level rise as a result of climate change is a major threat. Widespread loss of saltmarsh habitat is predicted if warming exceeds 2°C, threatening coastal wildlife globally. Reductions in coastal habitat quality are also expected but their impact and timing are unclear.
In North Norfolk, another key issue is disturbance by people. It was clear that in areas with numerous access tracks onto the saltmarsh, the number of Redshanks was lower. People can help by keeping to the paths and ensuring dogs are on leads.
What does this mean?
The results underline how important the North Norfolk and Humber estuary saltmarshes, as part of the east coast wetlands, are for breeding Redshanks, and provide a vital baseline for monitoring and conservation needed to help secure the future of the species in the UK. Redshanks are an indicator of the condition of saltmarshes, where populations are declining this can be one of the earliest warning signs of habitat deterioration. We already know that saltmarsh quality is declining for Redshanks in many areas like Suffolk and Essex due to increased flooding of the nests during high spring tides. Although saltmarsh in North Norfolk and the Humber is largely in good condition currently, there are key issues that need addressing if the future of Redshanks along the coast is to be secured.
With thanks to Holkham Estate, the National Trust, Natural England and the Norfolk Wildlife Trust for access permission and additional records. This work is part of a wider EU LIFE funded LIFE on the Edge project [2] and was part-funded by Natural England [3].
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Image credits:Redshank foraging on a muddy estuary in Norfolk. Ben Andrews (rspb-images.com).North Norfolk saltmarsh. Graham White.Redshank on fence post. Chris Gomersall (rspb-images.com).