It took five years to make it through the process, changed identity a couple of times, but the second foreign-ringed Marsh Warbler to be found in Britain has finally come to light.
When a slightly odd-looking Reed Warbler wearing a Norwegian ring was caught on the Suffolk coast in August 2004, no one at the time realised its true identity.
After a fair bit of investigation across the North Sea in Norway, this bird was actually pinned down as a Marsh Warbler. This could also be confirmed retrospectively from photos taken of the bird at the time, which have come to light recently (above). It was actually ringed as a young bird in Norway in July 2004, caught on autumn passage.
We have very few international movements of ringed Marsh Warblers, but the map below nicely shows where birds are coming from on migration, and where our birds are heading in the autumn. Green markers show the movement of the bird mentioned above, with blue markers showing where British-ringed birds have been found and red markers showing where birds found in Britain originated.
View Marsh Warbler in a larger map
Thanks to the ringers in Suffolk (who shall remain anonymous) for sorting this out and letting us know about the cock-up.