First British-ringed Stonechat for Norway - rubicolus?

John Secker from Thetford Forest Ringing Group writes:

Since 2003, Stonechat breeding in the Forestry Commission’s Thetford forest on the Norfolk/Suffolk border have been surveyed. The population has been as high as 56 pairs (2008, after a run of mild winters), and down to just four pairs (2014 after a run of relatively cold winters). In 2006 a project to find nests, and colour-ring both chicks