I came across these colour-ringed turnstones while I was watching twites at Druridge Bay. I didn't appreciate their significance until I got home and looked them up.
Each bird has a yellow flag on the right tibia, a standard metal ring on the left tibia, and three colour rings on the tarsi.
I found out on Dave Elliot's blog that the birds are part of a joint study by Northumberland & Tyneside Bird Club and Newcastle University into the home range of turnstones. Eleven birds were caught by rocket nets on the beach at Bondicarr, Hauxley at the end of December and were colour ringed, and fitted with a yellow flag and a radio transmitter.
I gather that all the flagged birds were fitted with a transmitter but the only aerial I saw is below (on the bird behind). They are due to fall off after three months or so so it may be that the others already have.
As I was mainly watching twites and shore larks I took only a few photos but now wish I had taken more. I haven't seen the turnstones again when I have been back.