Considering the hazards of migration and the massive distances involved, it's quite amazing that birds make it back to breeding sites year on year. But just occasionally there's a bird that bucks the trend...
One such bird was Sedge Warbler Y931333, originally ringed on migration in Sussex on 1st August 2012. It presumably spent the winter in sub-Saharan Africa, but was recaught on 4th May by ringers at Lázně Bohdaneč in the Czech Republic. When recaught this bird was sexed as a female, so was presumably in breeding condition, so why it was migrating through Sussex in a previous year is a mystery.
The BTO's
online ringing report (with the map below) shows that this is actually the furthest east recovery of a British-ringed Sedge Warbler from over 100 years of ringing, beating the previous bird which is the only other British Sedge Warbler to be found in the Czech Republic. Coincidentally, this bird was also ringed at the same site in Sussex, in August 2003!
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Maybe not a coincidence, perhaps there is some connection between populations that pass through Sussex and Czech republic. Such as they mix on wintering grounds and sometimes populations may get a little mixed and birds return together to one area even if on a previous year one went elsewhere?
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