Bats and Bridges

Late last month I attended an event with the West Yorkshire Bat Group where I learned how to survey for bats using bridges as roosts.

We met at Kirkstall Bridge in Leeds where we worked as a large group to look at the various features. Metalwork on bridges is not favoured by bats as it conducts the heat away and can be too cold, so we were looking for small cracks in the stone-work of the bridge.  Rubbish from the recent winter floods was in evidence, but we found few crevices suitable for bats on that first bridge.

We then split into two smaller groups, and my group went for a walk along the Leeds-Liverpool canal taking in two further bridges. This took us alongside Hollybush Farm, and the canal towpath was well used by people walking, biking or jogging, but it was still peaceful compared to the busy roads above.

The first bridge showed little promise, though we did see an American Mink on the opposite bank. This is an invasive mammal that predates on our native water voles and is a menace on the water ways, but as I watched I could not help feel sorry for this maligned animal that is just trying to survive in a situation it has found itself in.

The second bridge along showed a bit more promise, with some cracks in the stonework, and mature, ivy-clad trees in woodland along the bank of the canal. It will be interesting to see if dusk surveys are carried out later in the season and whether they capture bat calls using the canal as a foraging corridor.