With this ring...

It's obviously not a ring, but looks a bit like one. If anyone can identify it, I'd be glad to know. 
This hopeful robin came to see if my 60mm lens was a giant worm.
Although they might look similar, each robin's red breast pattern is apparently unique, rather like our fingers. I'm not sure how they've been able to confirm this, as taking prints can't be easy, or popular with the birds.