Bat Sonograms

When we undertake a bat survey we are effectively sampling the survey area for the presence of bats to identify the species and where possible the population status within a site.

Using Ultra Sonic detectors we can record bat echolocation calls and analyse them on bespoke software to analyse the sonogram (bat echolocation call).

All UK bats use echolocation, bursts of sound pulses, when flying.  A bat makes an echolocation call with each beat of its wings emitting a short, high frequency sound. The echoes help the bat to make a sound image of their environment.

The sonogram can be broken down into three sections;

1] Searching - long open calls where bat is searching for prey (tiny insects);

2] Approach – where a bat has identified a prey item and increases the frequency of calls to catch it; and

3] Feeding – A short series of calls that sound like a buzz.

In relation to planning works or a development, the aim of surveying is to identify and assess the potential impacts the proposed works is likely to have on local populations of bat species present on and around the site and provide mitigation measures where required.

Stewart Parsons