British Bat Echolocation Key

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Identify British Bats

The online tool below has been made to help identify Bats that are usually found in the UK, using the sound of their calls and has been developed from an original British Bats Echolocation Key created by the Bedfordshire Bat Group, which is available as a PDF from the Wildlife Trust.

This interactive British Bat Echolocation Key is based on the typical calls of common British Bats, as the sound is heard on a Heterodyne Bat Detector. Some added points relating to sonograms have been included, these are only of use with a Frequency Division or Time Expansion detector. This is used to produce a sound file that can be downloaded to a computer with sound analysis software.

Points to Consider:

  • British Bat calls are very variable, they are often affected by the nature of the bat’s surroundings. In unusual locations or circumstances, the bat calls may change significantly from the normal pattern for the bat species in question.
  • In specific environments such as woodland, the bat calls of many species will sound quite similar. The bats adjust their calls to suit the nature and topology of their surroundings. The environment must always be kept in mind when you record and identify bat calls.
  • Accurate ID of bat species from echolocation calls is not always possible. Added info about the appearance of the bat, the pattern of flight and the environment will often help.
  • This online British Bat Call Key does not cover social bat calls.
  • This Bat Call Key covers only the 16 (or 17) resident British Bat species.

IMPORTANT: This British Bat Call Key will not be of use to identify vagrant European Bats, even for an approximate ID and may give very misleading results.

Detecting British Bat Calls

It is essential that the Bat Detector is used actively when you try to identify bat calls. By adjusting the tuning until specific aspects of the bat call have been recorded and/or noted:

  • Frequency range of the bat calls to be identified
  • Frequency at which the bat call sounds loudest
  • Sound quality of the bat call at different frequencies
  • Any apparent drop in volume at different frequencies
  • Repetition rate of the call (rapid, medium or slow)
  • Regularity or irregularity of the rhythm of calls
  • Any apparent volume fluctuations in the call

Taking account of all these factors requires considerable practice with the Bat Detector, because of this it may take some time before reliable bat call IDs can be attempted.

Identify Bat Calls

To identify British Bats by call simply read the questions below and select the one that best matches the sound of your bat’s call. Repeat the process on each page until you reach an ID for the bat call you have.

After using this interactive British Bat Echolocation Key to ID the bat call you have recorded; you can find out more about the species of bat that you have found from the ID page. You can also share your bat call ID to the National Bat Monitoring Programme. Where it will help to support monitoring and care of bats in the UK.