Yellow legs and Black heads in Switzerland

We recently received a partial ring-read of a Black-headed Gull in Switzerland which did look to be a BTO-ringed bird, so definitely one worth chasing up! A few emails later and a week after first seeing the bird at Morges, Franck Lehmans was able
to read the ring again and get the full number (EX70855); a bird ringed
as an adult at Pitsea Landfill Site in October 2012.

This is only the second