In 2020, a team from the Institute for Waterbirds and Wetland Research (IWWR e.V) led by Dr Helmut Kruckenberg began a programme of marking nesting Curlews with satellite tags, which enable the movements of birds to be tracked over long periods. The maps of the routes taken by migrant Curlews are now available online, and Dr Kruckenberg has kindly allowed us to post a link to the website: www.blessgans.de/?891. The maps show the departures from Germany to their wintering sites, and in some cases the first movements back towards their German breeding grounds in early 2021.
The website reveals the astonishing variety of wintering strategies adopted by migrant Curlews which nest in the western part of Germany: some move to the British Isles, (one to Ireland, several to south Wales, some to East Anglia, some to the New Forest). Others move just the short distance to the Wadden Sea, while some move much further south along the Atlantic coast to the Channel Isles, Normandy, Brittany, and as far as Spain and Portugal. The maps also reveal the dates on which the birds made their movements; the speed of the migratory movements is striking.
Note that it is important to tick only one data box at a time, otherwise you get confusingly overlapping flight tracks; note also that, when you click on the chart, it gives the date of each observation; if the last date is a long time ago, the tag has either fallen off, or the bird is dead. Thus 019 at the Wildfowl and Wetlands Trust Centre at Llanelli on the Burry Inlet is known to be dead, as the body and tag were retrieved from the shoreline; 025 on the Severn Estuary and 059 at Newport Wetlands may well be dead, perhaps predated.
048 is particularly interesting. It left north Wales and flew across the North Sea to the Netherlands on 9 February 2021 before the recent cold snap, but then, on meeting adverse conditions, flew back across the North Sea to Norfolk. 064 has also returned from Spain to Germany in the last few days. It seems likely that in the next few days, there will be further movements back to the breeding area.
Dr Kruckenberg reports that his institute plans to tag another 60 birds in spring/summer 2021, and these maps of their movements will eventually be available under the heading Curlew Migration 2021.
If you are also interested in geese, there is a similar website on tagged geese at www.blessgans.de