Nature Blog Network

#OnePlaceEnvironment: Counting Bats

I was given a bat detector for my birthday a few years ago and spent a number of happy evenings sat in the garden as dusk fell watching the bats.They seemed to roost somewhere over Sion chapel, and flew over the roof of Springhill House in a manner reminiscent of the Valkyries.

We wandered over Marl Pits and gradually began to get an idea of the different types of bat and the way the detector picked them up, although the predominant species were mainly pipistrelles and soprano pips. The natural next step was to volunteer for the Bat Conservation Trust's Waterways survey. Aimed at people with relatively little experience, this involves walking a1km route along a river, stopping every 100m to count the number of Daubentons bats fllying over the surface. I was fortunate enough to be allocated a stretch of river pretty close to Springhill and on a right of way throughout, although interesting the Bat Conservation Trust gave me a point which isn't actually on the river…

So twice in August I was found by the side of the river 40 min after sunset armed with a bat detector, torch and timer. The idea is that you use the detector to indicate when bats may be present then confirm they are Daubentons' by shining the torch over the river surface and watching for the typical surface skimming. This is my fourth year completing the survey with a break in 2020 due to covid and 2019 when I dropped the torch in the river. Bat numbers have held up pretty well over that time, though there has been a drop after the two-year gap.

It's a pleasant hour or so wandering along the river listening to the water tumbling and watching the bats, though the accompanying 'My Sharona' belted out by the band in the Con Club was a bit surreal. The really encouraging thing however is the improvement in river quality over the past 20 years or so which has made this possible. The Irwell was the dumping ground of the waste of industry from Springhill resident John Ashworth's collieries in the early C19 through to the dye mill whose effluent was the basis of my daily childhood game of 'guess the river colour. Children were warned that the river was toxic (which it probably was0 so we mustn't play in it (which we promptly did).

It was a joy therefore to wander along the river a few weeks ago and count 25 different bird species along a 6 mile walk, just as it was to walk 1km those evenings watching the bats. It is a testament to the power of nature to recover when people stop messing with it.