Two voles this evening again, eating very near to each other - you can see how close in picture two. I don't know whether this means they're mates or siblings; normally water voles are very territorial creatures, so I assume a close relationship between these two.
In looking at another stretch of the brook, I surprised a family of wrens, and managed to snap this just-fledged little chap. And this afternoon, at Fordhall Farm, I saw a kingfisher. Top day's nature-study!