This guy is a real vole specialist, spent the morning cruising the shoreline looking into the tall grass to spot voles. He managed to catch a number of them in the tall grass and as usual with herons, he takes the prey back to the water to pre-soak the fur before swallowing them down.
Thanks for your comments everyone, much appreciated. Interestingly there are two herons in the large pond where these shots were taken. This individual feeds almost exclusively on voles, the second individual focusses on fish, never seen the second heron hunting voles.