Many British bats can be identified to species from characteristics of their echolocation calls, while others can be identified at least to genus (e.g. Vaughan et al., 1997). Bat detectors therefore provide a non-invasive means of assessing patterns of habitat use by different species. We have developed the Automated Ultrasound Recorder (AUR) that can be used to remotely monitor bat echolocation calls in a variety of habitat types. The AUR differs from most other automated bat detection systems in that it uses a broad-band detector, which preserves the key acoustic parameters of the calls for later analysis. The bat detector used in the AURs is the Pettersson D140 switched to time expansion mode. When the system is triggered by ultrasound the detector records for 870ms. The time-expanded recording is then downloaded onto a Sony Walkman (WM-D6C) cassette tape recorder, along with a time signal indicating when the unit was triggered. Recorded calls can be analysed using BatSound (Pettersson Elektronik), or other sound analysis software.

The applications of the AUR in bat research and conservation were tested as part of a DPhil research degree. For more details, click here.

References:
Vaughan, N., Jones, G., Harris, S. (1997) Identification of British bat species by multivariate analysis of echolocation call parameters. International Journal of Animal Sound and its Recording 7, 189-207.