Last nights walk was a real treat, as well as the aforementioned Pipistrelle bats, the water voles were also out and in a different part of the Ock - more westerly and could be viewed from the bridge. Four sightings in total.
It's great news to see so many of them, as water voles are britains fastest declining mammal - with a 90% decline in numbers in recent years - attributed to pollution, habitat loss and american mink - escaped or released from fur farms, (fur farms a practice banned in England and Wales since 2000 and in Scotland since 2002).
In fact, it looks like the colony at Radley Brook near the Thames to the north of Abingdon is extinct, I haven't seen a water vole there for two years now. The colony has possibly been predated by american mink that may have moved into the area (although I haven't seen signs).
More information on water voles can be found at: http://www.abdn.ac.uk/mammal/water_vole.shtml
Here is the map of last nights sightings:
View River Ock #2 in a larger