Assessing Biodiversity Using Sound Recordings – An example of research performed at the Museum für Naturkunde Berlin (Karl-Heinz Frommolt)
The Animal Sound Archive at the Museum für Naturkunde Berlin is one of the oldest and largest collections of animal voices worldwide. It was founded in 1951 for scientific research in the field of behavioural biology and comprises now 120.000 sound recordings. The major part of the old analogue tapes has been already transformed in digital format. Digital recording and processing techniques open up new fields of application.
Through acoustic analyses animal vocalizations can be objectively described in the frequency and time domain. Even old sound recordings, like the oldest wildlife recording in the archive, have a good quality and are suitable for acoustic analysis. This recording of a tawny owl was made on October 30th 1951. Only the running noise of the tape recorder is a bit annoying.
The sound recordings stored in the Animal Sound Archive provide us with an excellent reference material, enabling us to apply modern methods of acoustic signal analysis and detect automatically bird species within a very complex soundscape. We focus on application scenarios, where an acoustic approach has significant advantages over the acquisition by a human observer.
Methods of acoustic pattern recognition enable to reliably detect individual calls of Spotted Crakes (SpCr) in the spectrogram. As template clean calls were used from the Animal Sound Archive were used. The marks were set automatically by the program (Avisoft SASLabPro, © Avisoft). The automated analysis allows investigate even several days of continuous recordings.
Images: Karl-Heinz Frommolt, Hwaja Götz, Klaus Henry Tauchert, Andreas Wessel
Audio: Karl-Heinz Frommolt, Günter Tembrock
Spectrograms were created using Rava Pro Version 1,4 (© Cornell Lab of Ornithology)
Text: Karl-Heinz Frommolt (Museum für Naturkunde Berlin)