GIZZARD STONE

This is the first time I've encountered a shag hunting for Gizzard stones.  My pigeons love to get grit for their gizzards and I can only (at this stage) assume this bird is doing the same.  The careful observer will see the stone being held in the hook of the beak before swallowing it.
I've been struggling the last couple of days with the new lens but I think this one shows me its pin sharp ( even at 100% size increase-which is my test for a sharp image) Happy - thanks David.

PS acouple of extras today to encourage me in my quest for IS sharpness.
rgds poo