colour ringed barwit

[brianward]

Last Saturday, 11th of May, there was a small group of black tailed godwits and 3 bar tailed godwits in front of the seal sands hide. I managed to get a photo which I posted on twitter of a barwit with colour rings. It had an orange tag above a red ring on its left leg and a white ring above a blue ring on its right leg. Anyone able to shed any light on the origin of these rings.