Her er svaret fra den polske ringmærker. Thank you for the very nice record of Caspian Gulls.
They were ringed in Jankowice gravel-pit near Zator, Oswiecim province in southern Poland in 6th June 2006. There is a colony of Caspian Gulls numbers about 130 nests but few Yellow-legged Gulls breed there too.
Do you took the photos of these gulls? It will be very interesting for me how look ringed gulls in juv/1w plumage.
Jacek Betleja, PhD
Department of Natural History
Upper Silesian Museum
pl. Sobieskiego 2
PL - 41-902 Bytom