Last Friday night was a first for me – I found myself without a torch in our local park hunting for bats. It didn’t occur to me to take a torch but fortunately there were plenty of other people there to whom it had occurred and a great time was had by all.
Steve Lucas, Welsh Bat Officer with the Bat Conservation Trust gave a fascinating talk/slideshow about the various species of bats and their habitats until it got dark. Then we ventured out and were given bat detectors to use in the woods and along the hedgerows. We heard three different types of bat in Coedbach Park – Common and Soprano Pipistrelles and a Whiskered bat.
Seeing with Sound – The bat detectors respond to the very high frequencies bats use as their “sonar device” to detect and catch insects and “see” their surroundings – bats, however, are not blind. The frequency range of a Pipistrelle bat is around 45Khz (kilohertz). The range of the RODE NTG-3 shotgun mic I use for StillWalks recording (see the last blog entry) has a range that goes up to 20Khz and so has no chance of picking up the sound of bats!
The sound file above is a recording of the output of the bat detectors we were using made on my Edirol RO9 recorder – the hiss is mostly from the bat detectors but the sound patterns of the bats are quite clear. Adults and children alike were excited and fascinated to hear the bats at first hand rather than on a TV programme and I, for one, am looking forward to the next time.