Leg Ringing

I have noticed that one of the starlings that visits my bird feeders has a yellow ring on his left leg and a silver ring on his right leg anyone know why this would be?
  • There are a lot of people who carry out bird ringing on reserves & other places for various reasons. Normally there should be a code of letters or numbers on the yellow ring, the silver ring is only useful if the bird dies or is recaptured as it also gives details of the "ringer". Have a look on this page, there are several ones with yellow on the left leg cr-birding.org/colourprojects;tid_2=&tid=All&tid_1=All&tid_4=All&tid_5=All  

    I hope this helps. If you can take a photo the code might be readable.