Occasional posts on subjects including field recording, London history and literature, other websites worth looking at, articles in the press, and news of sound-related events.

02 May 2010

Nocturnal emitters

LAST THURSDAY EVENING was spent at a Bat Conservation Trust training workshop in the Wildlife Wetland Centre in Barnes. After being taught how to identify four different bat species by their sonar clicks, we trainees were led on a walk around the Wetland Centre, bat detectors pointing hopefully this way and that.

Five different species were heard that evening: Common and Soprano Pipistrelles, one or more Leisler’s bats hurtling crazily around a hide, the plodding clicks of a Noctule, and the geiger-counter rattle of a Daubenton’s bat as it skimmed over a lake like a puck. Two recordings turned out okay.

This brief one is of a Soprano Pipistrelle, so named because its sonar clicks are squeezed out of its small body at around 10kHz higher than the Common Pipistrelle:

The Liesler’s bat (or, possibly, bats) put in a good performance near a hide, and its silhouette could be seen tumbling across the cloudy night sky:

The bat detectors pick up a fair amount of noise, but somehow that sounds right, like you’re listening to some unfathomable short-wave radio station. The bat detector used was a Magenta Bat5, which you can buy directly from the manufacturer for about £90. You can use it for recording other animals as well: some grasshoppers, crickets and moths, as well as rats and mice, use ultrasound for signalling.