Fisher, R.M. & Weary, D.M. (1988) Buzzing bees: communication between bumble bees social parasites (Hymenoptera: Apidae) and their hosts. Bioacoustics vol 1(1): 3-12
Abstract
Although sounds are produced by highly eusocial bees in a variety of contexts, their meaning and evolution are poorly understood. In this study we examined the communicative function of sound during dominance disputes in primitively eusocial bumble bees (Hymenoptera: Apidae). The interaction between sound production and dominance behaviour was studied in the context of parasitism by obligate bumble bee social parasites (Psythyrus spp.). Females of Psithyrus bohemicus and P. vestalis produced sound during dominance interactions in bumble bee host colonies. Parasites mauled and pushed host bees, after which they buzzed with their wings folded. The sounds were broad band, with a mean frequency of 820 Hz for the loudest harmonic produced by a P. bohemicus female. The frequency range of recorded sounds matched that of the vibratory stimuli to which isolated bumble bee workers responded. Buzzing by some bumble bee social parasites may assist them in advertising a position of dominance in egg-laying hierarchies established in the absence of pheromonal inhibition of ovarian development.
Pallett, J.R. & Passmore, N.I. (1988) The significance of the multi-note advertisement calls in the reed frog, Hyperolius tuberilinguis . Bioacoustics 1(1): 12-23
Abstract
The reed frog Hyperolius tuberilinguis is a prolonged breeder with an advertisement call that varies in complexity from one to six click notes. Call complexity increases with chorus size, but calls containing more than three notes are rare. In playback experiments to males, subjects responded by increasing the complexity of their calls, without closely matching the stimulus and rarely exceeding the stimulus in complexity. Stimuli less complex than their own evoked a reduction in complexity. Call repetition rate remained unchanged in the responses. In two-choice phonotaxis experiments, females discriminated against one-note calls, and two- and three-note calls were the most attractive. Males thus adjust their calling in the presence of neighbours to a pattern most preferred by females. Calls of higher complexity may be more easily detected or located by females in the noisy environment of a chorus.
Heymann, J. & Bergmann, H.-H. (1988) Incomplete song strophes in the chaffinch Fringilla coelebs L.: general influences on a specific behavioural output . Bioacoustics 1(1): 25-30
Abstract
Incomplete song strophes in free-living territorial Chaffinch males can be induced by different experimental as well as natural stimulus situations including replay of species-specific song, approaching of human beings, and aggressive encounters with con-specific males. While the first post-stimulus song strophe is shortest the following ones gradually attain their full number of elements again. The strength of this reaction differs with regard to different stimuli.
Keuper, A., Weidemann, S., Kalmring, K. & Kaminski, D. (1988) Sound production and sound emission in seven species of European Tettigoniids. Part I. The different parameters of the song; their relation to the morphology of the bushcricket . Bioacoustics 1(1): 31-48
Abstract
Comparative studies of sound production and sound emission in seven species of European tettigoniids have been carried out. The species chosen were two Tettigoniines (Tettigonia cantans, Tettigonia viridissima), two Ephippigerines (Ephippiger discoidalis, Ephippiger ephippiger), and three Decticines (Decticus albifrons, Decticus verrucivorus, Psorodonotus illyricus). The factors which determined the choice of species were the different morphology (for example body shape and weight, and wing size) of the three subfamilies. The parameters of the different songs (e.g. dominant frequency, intensity) are normally not correlated to any of the investigated morphological characteristics of the animals. In the brachypterous species intraspecific correlations exist between wing size and the dominant low frequency band of the call. This frequency band is also observable at related higher frequencies in the ultrasonic range (20-60 kHz), the observed band width increasing with frequency. Sound emission in all species is to some extent directional. This directionality is related to body size and wing structure. The song structure of the different species does not appear to be related to any observable characteristic of the habitat of the animals. A possible exception may be the song of Psorodonotus illyricus with a particularly low dominant frequency band. The pathogenetic development of the songs seems to be determined by relationships between the different species rather than to any factors contributed by the habitat.
Mierauskas, P. & Buzun, V. (1988) Acoustic signalling of the great black-headed gull Larus ichthyaetus Pallas . Bioacoustics 1(1): 49-56
Abstract
Observations made on the behaviour and sound recordings made of the calls chiefly in the early part of the breeding season in the South Ukraine indicate that the Great Black-headed Gull Larus ichthyaetus has a limited vocal repertoire, producing only eight different types of call associated with various behavioural contexts. Sonagraphic analysis of these sounds shows that their harmonic structure is confused, like that of the calls of L. melanocephalus and L. relictus and unlike the stronger harmonic organization of the calls of L.argentatus, L fuscus and L. marinus. Furthermore, there is no signal warning of approaching danger. This acoustic evidence supports the theory that L. ichthyaetus is more closely related to L. relictus and other ''primitive hooded'' gulls than to L. argentatus and other ''large white-headed'' gulls of the genus.
McGregor, P.K., Walford, V.R. & Harper, D.G.C. (1988). Song inheritance and mating in a song-bird with local dialects. Bioacoustics 1(2-3): 107-129
Abstract
In this paper we document the pattern of geographic variation in song of the Corn Bunting in a marked population in Sussex. Song variation is best described as a system of local dialects with three song types in each dialect. We examine the inheritance of dialects from father to son; sons sing the same dialect as their nearest neighbour, rather than inheriting the dialect of the father. Therefore songs seem to relearned after dispersal. We also compare the dialects of mates and fathers of females; our results suggest that females do not rely on dialects when pairing. These results are discussed in the context of the current controversy surrounding other species with dialects and hypotheses relating dialects to the genetic structure of populations.
Edds, P.L. (1988). Characteristics of finback Balaenoptera physalus vocalisations in the St. Lawrence estuary. Bioacoustics 1(2-3): 131-149
Abstract
Sounds produced by Finback Whales Balaenoptera physalus were recorded from a stationary hydrophone in the St. Lawrence Estuary from June to September. The vocalizations consisted of frequencies below 120 Hz; impulsive sounds had frequencies up to 1 kHz. Over 80% of the sounds were downsweeping calls. Frequency variations in the downsweeps were correlated with social context. Constant calls, upsweeps, wavers and a frequency and amplitude modulated call were rare and may be context specific. Vocalization rates varied with the number of animals present and context, but could not be used as a census technique. Comparisons are made with the data from other investigators in both the Northwest Atlantic and the Northeast Pacific. Frequency and time characteristics for Finback downsweeps are summarized and discussed as components important for species recognition.
Abs, M. & Jeismann, R. (1988). Do courtship songs differ individually in the domestic pigeon Columba livia domestica? Bioacoustics 1(2-3): 151-157
Abstract
Measures of six temporal relations in the pigeon's courtship songs from four individual males which differed in age and courtship experience were taken. Intra- and interindividual variation was studied. Individual long term vocal stability is especially found in the whole length of the strophe, the length of the "trill'' phrase and the length of the "coo".
Horne, J.F.M. & Short, L.L. (1988). Afrotropical bird vocalizations: a review of current problems. Bioacoustics 1(2-3): 159-170
Abstract
Knowledge of the vocalizations of Afrotropical birds is very limited and many problems exist. Seasonality of vocal activity has not been properly researched in the context of potential variability in the times of breeding. The different types of duetting and chorus singing, as exemplified by the African barbets, Capitonidae, need to be studied to correct the over-generalized treatment of this subject. Fuller information is required about geographic variation of those vocalizations which there is a tendency to use as criteria for taxonomic separation of species. Other problems which invite more research are mimicry, nocturnal and diurnal song, the extent of species' repertoires of calls, and vocalizations during breeding activities. There is an urgent need for more studies to be made of the vocal behaviour of birds in Africa where threats to the habitats are increasing so rapidly.
Keuper, A., Weidemann, S., Kalmring, K. & Kaminski, D. (1988). Sound production and sound emission in seven species of European Tettigoniids. Part II. Wing morphology and the frequency content of the song. Bioacoustics 1(2-3): 171-186
Abstract
Sound production in seven species of bush crickets (Tettigonia cantans, T. virridissima, Decticus verrucivorus, D. albifrons, Psorodonotus illyricus, Ephippiger ephippiger, E. discoidalis) has been investigated. Aspects of wing morphology have been compared and show that areas of the dorsal fields and the mirror are correlated with the dominant frequencies of the songs. Tooth removal from the pars striders produces gaps in the time structure of single syllables but no change in the song power spectra. The removal of the terminal lateral field in long- and medium-sized wing species (T.c., T.v., D.a., D.v.) produces an increase in the ultrasonic components of caudally-emitted sound. This suggests an absorbing function for the lateral fields in intact animals. In all species removal of a small portion of the mirror frame or of the mirror membrane attenuates the whole stridulatory signal, but especially the ultrasonic components. The mirror therefore functions as an amplifier, especially for high frequencies. Manipulation of the dorsal fields of long- and medium-winged species, or the distal edges of tegmina of brachypterous species, deletes or shifts the songs' dominant frequency. Thus the different tegminal structures (and especially the dorsal fields) contribute to the time structures and power spectra of the stridulatory songs of these species.
Beecher, M.D. (1988). Spectrographic analysis of animal vocalizations: implications of the "uncertainty principle". Bioacoustics 1(2-3): 187-208
Abstract
Many animal vocalizations are non-periodic, frequency-modulated signals. Because this type of signal varies simultaneously in two dimensions, time and frequency, spectrographic measurement is constrained by the "uncertainty principle": to increase accuracy of measurement in one dimension we must sacrifice accuracy of measurement in the other dimension. Although this trade-off is unavoidable, inherent in the measurement of frequency, for any particular frequency-modulated, non-periodic signal, there is an intermediate, optimal setting of spectrographic bandwidth, equal to the square root of the average rate of change of the measured signal. This optimal bandwidth minimizes the time-frequency smear, and thus permits the most accurate measurement of the instantaneous frequency. Investigators analyzing the microstructure of animal vocal signals therefore should choose their analyzer bandwidths to match the signals under study.
Brown, C.H. (1989). The measurement of vocal amplitude and vocal radiation pattern in blue monkeys and grey-cheeked mangabeys. Bioacoustics 1(4): 253-271
Abstract
The substitution method was adopted from industrial acoustics (Francois and de Montussaint 1972) to “eliminate the influence of the environment'' on measurements of the amplitude of vocalizations given by blue monkeys Cercopithecus mitis and grey-cheeked mangabeys Cercocebus albigena. Measurements were conducted of sound power and sound pressure level of representative utterances. Monkey vocal radiation patterns were also measured. The results showed that vocal amplitude ranged from 62 dB to 100 dB in sound pressure (re l pw). At a distance of 2 m, the loudest calls approached an amplitude of 110 dB SPL, a level about equal to the loudest human yell. The measurements of call amplitude conducted here exceeded those derived from the field by approximately 10 dB. It was shown that the discrepancy in amplitude between these laboratory based measurements and earlier measurements conducted under field conditions (Waser and Waser 1977) was probably due to destructive interference between the direct wave and the “ground wave'', a phase shifted wave reflected from the ground. Measurements of radiation patterns of primate vocalizations showed that, like human speech, directivity was a function of frequency, with high-frequency components being radiated mote directionally than lower-frequency components. However, primate utterances were in general radiated more omnidirectionally than was human speech.
Nurnberger, F., Siebold, D. & Bergmann, H.-H. (1989). Annual changes of learned behaviour - variation of song pattern in free-living chaffinches, Fringilla coelebs, during the breeding season. Bioacoustics 1(4): 273-286
Abstract
Seasonal changes of parameters of full song were studied in a free-living population of chaffinches Fringilla coloebs during one entire reproductive period. Approximately 7000 strophes sung by 14 male chaffinches were recorded and analysed by sonography and a particular oscillographic method. While the general pattern of song strophes, i.e. characteristics of elements, number and arrangement of phrases, and final flourish, remained constant throughout the reproductive period, full song varied with respect to the repetition rate of strophes, number of strophe types used, intensity of singing, duration of strophes, and percentage of incomplete strophes sung. These changes are discussed as results of learning processes, social interactions in the population, and endogenous mechanisms activating memorized information.
Keuper, A. (1989). Sound production and sound emission in seven species of European Tettigoniids. Part III. Determination of the mechanism of sound production using the cepstrum analysis. Bioacoustics 1(4): 287-306
Abstract
The mechanism of sound production in tettigoniids is examined by applying the method of 'cepstrum' analysis to insect calls. The power cepstrum is defined as the inverse Fourier transform of the logarithmic power spectrum. This analysis shows that the tettigoniid sound signal is a convolution in time of probably two components. The first is caused by the initial impact of teeth of the stridulatory file on the left wing against the plectrum on the right wing (termed the input pulse); the second is caused by the oscillating properties of the tegmina (these being a function of the intrinsic frequencies of dorsal fields and mirror and their damping properties). In the cepstrum each component appears as a varying number of peaks. The tooth impacts cause a very low frequency peak probably representing the time in which the two tegmina are in contact during each impact and high frequency peaks representing the impulse repetition rate. The oscillating properties of the tegmina cause two major frequency peaks which can be clearly related to the size of the dorsal fields and of the mirror respectively, and therefore to their intrinsic frequencies. The high damping factor of the tegmina together with the transient shape of the tegminal input pulse causes a strong time limitation of the impulses and is therefore responsible for the broad frequency bands occurring in the power spectra of the tettigoniid songs. The impulse generation of a synthetic tettigoniid song is discussed.