Paper with this title will appear in the slovenian journal Muzikoloski zbornik, 33 (1997): 5-21, published in Ljubljana, Slovenia
The Summary of the paper is available here.
There are many examples of animal sounds or vibration signals mentioned in this paper and presented in the form of oscillograms and sonograms. To get a better idea about these communication we present here the following examples of the animal sound and vibration signals.
Vibrational signals and songs are produced by many insects, among most interesting ones are produced by small bugs (Heteroptera) of the family Cydnidae. The signals are produced by two different mechanisms, a stridulation and by a body vibration or a simple tymbal mechanism. For their communication only the substrate vibration and not the airborne sound is crucial.
Our example will be the bug Tritomegas
bicolor
By stridulation it produces short irregularly repeated signals, when touched, attacked or disturbed in another way. The signal is called disturbance call (sound sample: bicolorM1.au )
More interesting are the vibrational songs during courtship and mating. Males produce first courtship song (MS-2) with repeated phrases composed by low frequency part followed by stridulatory chirps. After some time the male switches to the intense second courtship song (MS-3). If the female is receptive, it responses with prolonged high pitched stridulatory chirping (FS-2). These signals can be heard as a whole sequence and seen separately in the following illustrations:
MS-2
FS-2
and MS-3:
Among the courting males comes often to the rival alternation:
MS-R:
with
the male's courtship (vibration) song strongly reminding the
drumming solo of a jazz musician.
It has many vibrational songs and one of them is used in alternation between males, females or even youngs. Let's hear two alternating animals. These bugs answer with such vibration signals also to various sounds and even to human speech or whistle and mimic the duration of such sounds. One can listen to such alternation between a bug (Ph) and an experimentor (H) and see the sonagram below:
In contrast to European cicadas there
some species sing like birds with high
degreee of frequency modulation what sounds
like this.
A number of singing cicadas is in many sites so high that they
have to share time of singing with other species in a certain order
to enable efficient communication. Therefore the sounds in the
rainforest change from hour to hour as can be shown in the next
examples from the Belum Forest, Malaysia. The next five sound samples
can be heard using RealPlayer:
morning belum1.rm, before noon belum2.rm, afternoon belum3.rm, evening belum4.rm , night belum5.rm
More examples on songs of tropical cicadas can be heard in the homepage about Asian_cicadas.
Surprizing are also songs of many tropical birds, some of them are singing in major or minor scales up (a) or down (b) like Myiophoneus caeruleus (a - see below!)
One of the most complicated and phantastically coordinated sound emission which I heard and recorded in the National Park of Taleban (Thailand) was the singing of two gibons in polyphony. Lets hear a short sequence of such glissando shown also in the graph below.
The author, biologist with some musical education and experience is 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, variability of animal songs, and 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 rain forests is mirrored in the richness of soundscapes, especially in S.E. Asia .? The author was during his expeditions especially impressed by acoustic diversity of tropical cicadas, characterized by for insects unusual high degree of frequency modulation and with 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 rain forest is a never ending symphony of nature, changing from hour to hour, with the climax at dawn.
Recently many musicassettes and CD-s 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*). Digitized sound samples used for this
paper are available here on Internet. But one should prefer listening
to the real sounds in nature...
*) As an example one can listen to such "bioacoustic composition" dotiki.rm by B. Perovsek using the RealPlayer. It contains sounds of synthesizer, accordeon, and more than 16 species of crickets, cicadas, bugs, bees, frogs and birds.
Last update: 17.2.98
Matija
Gogala