Find a feather – a seaside treasure hunt

28 Jul 2022 | No. 2022-30

At this time of year, most British Shelduck migrate across the North Sea to find a safe place to moult. Many encounter existing or planned offshore wind farms along the way, while flying at altitudes that set that could set birds on collision courses with sweeping turbine blades. Analysing the feathers they lose will allow scientists to develop a deeper understanding of Shelduck migration routes, something that will inform future planning decisions and help to minimise the impact of vital renewable energy infrastructure.

Shelduck feathers are easy to spot, whether you’re building sandcastles, walking the dog or just soaking up some rays – or rain. The best ones to look out for are around 12–16 cm long, with one white side and another that’s either dark orange or iridescent greenish-black. They might not seem like much, but these feathers are real treasures that will make a big difference and could reveal information new to science. Just remember to wash your hands after you’ve touched them!

Shelduck moult all their wing and tail feathers together, leaving them flightless for between two and four weeks each summer. To keep themselves safe, UK Shelduck spend this time on mudflats both here and across the North Sea in Germany and the Netherlands. There are five known UK moult sites, but there may well be many more that we don’t know about yet. Could you help us find them?

Ros Green, lead scientist on the project, said: ‘Chemical compounds in a bird’s feathers can reveal so much about where the feather was grown and what the bird has been eating. Building up a picture of how Shelduck populations migrate is vital if we want to ensure that offshore wind farms – which are an essential part of our renewables infrastructure – don’t get in their way. 

She added: ‘Searching for Shelduck feathers is a perfect activity for the summer holidays. Beaches are full of all sorts of interesting things, so this is a great opportunity for kids to learn more about the world around them at the same time as making a real difference for science and conservation.’ 

For more details – and to find out where to send your feathers – head to

Contact Details
Tom Stewart
 (BTO Media Manager)
Mobile: 07585 440910
Email: press [at] (subject: News%20release%20enquiry)

Mike Toms (Head of Communications)
Mobile 07850 500791
Email: press [at] (subject: News%20release%20enquiry)

Images are available for use alongside this News Release. These can be downloaded from this link for which you will need to enter the password Tadorna2022. Alternatively, please contact press [at] quoting reference 2022-30.

Notes for editors 

The aim of this project is to establish the extent of connectivity between Shelduck moulting and non-breeding sites by conducting stable isotope analysis of feathers collected by the public from a range of moult sites. Previously unknown moult sites may also be identified. The project will reveal what proportion of UK Shelducks makes a sea crossing each year and how many may interact with offshore wind farms.

The work is funded by BEIS Offshore Energy Strategic Environmental Assessment programme and is managed by John Hartley of Hartley Anderson, BTO and University of Liverpool.

BTO is the UK's leading bird research charity. A growing membership and up to 60,000 volunteer birdwatchers contribute to BTO's surveys, collecting information that underpins conservation action in the UK. BTO maintains a staff of 100 at its offices in Thetford, Stirling, Bangor (Wales) and Belfast (Northern Ireland), who analyse and publicise the results of surveys and projects. BTO's work is funded by BTO supporters, government, trusts, industry and conservation organisations.

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