SUMMARY
The author, a biologist with some musical education and experience, has been working in the field of bioacoustics for more than 40 years. He wants to show on the examples from his investigations, mainly on insects but also on some other animals, properties of the animal sounds, interesting also from the musical point of view. Presented is the vast diversity of acoustic signals, the variability of animal songs, and the presence of some musical elements in these samples. One can find in animal songs complicated patterns and rhythms, regular alternation, imitation of other sounds, singing in tonal modes, singing in harmony with another specimen or specimens and even a kind of dancing in the rhythm of its own song. Most examples presented in the first part of this paper are from vibrational songs of European species of bugs (Insecta: Heteroptera) and in the second part from animals (cicadas, birds and mammals) recorded in the tropics. The biodiversity of tropical rainforests is mirrored in the richness of soundscapes, especially in S.E. Asia. During his expeditions the author was particularly impressed by the acoustic diversity of tropical cicadas, characterised by degree of frequency modulation unusually high for insects and for many species strictly singing only during specific short time window during the day or the night. There are also birds, singing in scales up and down, and gibbons, singing in polyphony. The whole soundscape of undisturbed tropical rainforest is a never ending symphony of nature, changing from hour to hour, with the climax at dawn. Recently many musicassettes and CDs are produced with recordings of soundscapes or selected animal sounds with the aim to substitute natural events, for meditation, as interesting acoustic background, or for scientific purposes. Some composers use recordings of animal sounds as sources of new ideas or even as material for bioacoustic compositions. Digitised sound samples used for this paper are available on internet at the address: http://www2arnes.si/~ljprirodm3/bioakustika.html. But one should prefer listening to the real sounds in nature...