Birdsong not just for the birds( Switch on the mike start the recordi...)

Switch on the mike, start the recording, the stage is set for the local fauna!

Computer scientists from the University of Bonn, in conjunction with the birdsong archives of Berlin's Humboldt University, have developed a kind of 'Big Brother' for birds. This has nothing to do with entertainment, but a lot to do with the protection of nature. The new type of voice detector involved can reliably recognise the characteristic birdsong of different species of birds, thereby facilitating surveys of the bird population.

Europe's forests are falling silent as countless species of birds go on the red list of endangered species. Yet in fact no-one can say what the exact position is with some species. So as to have a reliable count of the territories of indigenous birds it would practically be necessary to send out a whole horde of spare-time ornithologists to count the birds. What is more, since the birds are often hidden in the undergrowth or the tree tops, ornithologists need to rely on their ears and their specialist knowledge. This means that in many areas it is wellnigh impossible to map the bird population comprehensively and continuously.

In view of such problems environmental protection has to fall back on new technical methods. Some of these are now being provided by Bonn scientists. Computer scientists from the University of Bonn have developed detectors which can recognise birdsong automatically. What this implies is that in the preliminary stage microphones are placed at selected points in the wild; these record all the sounds made, in some cases over a period of months. The new computer software can then sift through the many hundreds of hours of recorded material overnight and say how many birds of which species have been singing and how often they have been doing this.

In his project Daniel Wolff of the Institute of Computer Science at the University of Bonn initially concentrated on the bio-acoustic recognition of the S
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