The restored section of the Cromford Canal (around 5 miles between Cromford and Ambergate) is designated as a biological Site of Special Scientific Interest. We didn't spot any voles, but, as we walked, we certainly enjoyed watching the water birds; including Moorhen and Mallard chicks, the odd Coot, and a number of Little Grebes (which were entertaining us beautifully with their underwater antics).
This particular Mallard and his mate were both settled comfortably on the wall as we approached. Unfortunately, a passing cyclist was just a little too near for the liking of the female and she took to the water. The male was somewhat braver, allowing us to creep quite close before he followed suit.
We were also curious about the number of air bubble streams rising up out of the thick water weed. Oxygenating plants perhaps? Or was something else lurking down there in the dense greenery? We never did find out.