@article {53123, title = {Male spacing and the influence of female courtship behaviour in the bladder cicada, Cystosoma saundersii Westwood}, journal = {Behavioral Ecology and Sociobiology}, volume = {9}, year = {1981}, pages = {269{\textendash}276}, abstract = {

1. Experimental choruses of males of Cystosoma saundersii with manipulated densities -12 times that usually found in bushes of the same size were set up and compared with choruses with natural densities of males. Greater numbers of both males and females were attracted to the louder, denser choruses.

2. There were higher rates of dispersal away from and movements within the experimental choruses than those found at natural densities. This indicated some form of repulsion occurring between males in close proximity.

3. Playback experiments to calling males in the field showed that males would stop singing and move away in response to high intensities of a conspecific calling song. The intensities eliciting this reaction cor- responded to a conspecific male singing at separations of less than or equal to 0.5 m. Aggression between males or aggressive songs have not been observed.

4. Females fly in to the chorus and alight generally within 0.5 m of the male of their choice. They then produce a pheromone which they disperse by wing-flicking. The rate of wing-flicking was used as a quan- titative measure of the willingness of a female to mate.

5. Twice as many females were attracted to higher densities of males than to natural densities. However, in the experimental situation, the probability of an attracted female actually mating was half that occur- ring in natural densities. This appeared to be due to an inhibition of the female wing-flicking behaviour.

6. Playback experiments showed that females will respond by wing-flicking to a male only when his song is at least 9 dB louder than that of his nearest neighbour (when the sound pressure levels of the sources are measured separately at the position of the female). Using this figure as a threshold, volumes in which females would respond were calculated for males with a series of nearest-neighbour distances. At the average separation found between males sharing bushes in the field, the volume in which a female would respond covered most of the volume in which a female is likely to land. Thus, the discriminating capabilities of the female were shown to govern the minimum separation occurring between males.

}, keywords = {Aggregation, amphibians, animal vocalization, Cicadas, Insect behavior, Insect sounds, Loudspeakers, mating behavior, Singing, Sound pressure}, author = {Jane M. Doolan} } @inbook {50785, title = {Primate Habitat Acoustics}, volume = {63}, year = {2017}, pages = {79 - 107}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, address = {Cham}, abstract = {

Natural habitats are not recording studios. Calls emitted in nature encounter an irregular assortment of hard surfaces that reflect and scatter the wave front, producing complicated patterns of constructive and destructive interference. The propagated wave front is subsequently disturbed by wind, thermal gradients, and atmospheric absorption. Collectively, these phenomena result in an unpredictable and untidy acoustic environment. Furthermore, thunder, rain, crashing waves, or the relentless chatter of biotic sources can result in high ambient-noise levels that may mask the signal, overwhelm the recipient, and obliterate significant nuances and embellishments. Thus, vocal communication is hampered by attenuation, reverberation, distortion, and acoustic disturbances. Accordingly, the twin components of vocal communication, sound production and acoustic perception, may have undergone persistent selection to counter the most prominent impediments to both hearing and being heard. Primates have radiated from rain forest to grassland and other habitats, and each habitat differs acoustically. Hence, there is reason to believe that the duration, amplitude, pitch, and composition of primate vocal repertoires, the timing of emissions, and the placement and orientation of vocalizers is not haphazard, but each has become tuned to the acoustic parameters of the natal habitat to heighten the clarity of vocal exchanges. This chapter begins with an overview of the acoustic properties of rain forest, riverine forest, and savanna habitats occupied by East African primates, which is followed by reviews of how primate calls become distorted when propagated in natural habitats and how distortion scores have been used to explore the acoustic adaptation hypothesis. Finally, significant opportunities for additional research are highlighted.

}, keywords = {acoustic adaptation hypothesis, ambient noise, amplitude fluctuation, animal vocalization, comparative bioacoustics, Distortion, excess attenuation, reverberation}, isbn = {978-3-319-59476-7}, issn = {0947-2657}, doi = {10.1007/978-3-319-59478-1}, url = {http://link.springer.com/10.1007/978-3-319-59478-1}, author = {Brown, Charles H. and Waser, Peter M.} } @article {47868, title = {Ticking of the clockwork cricket: the role of the escapement mechanism.}, journal = {J Exp Biol}, volume = {205}, year = {2002}, month = {2002 Mar}, pages = {613-25}, abstract = {

The \&$\#$39;clockwork cricket\&$\#$39; model for cricket sound production suggests that the catch-and-release of the file of one forewing by the plectrum on the opposite wing act as an \&$\#$39;escapement\&$\#$39; to provide the phasic impulses that initiate and sustain the vibration of the resonant regions of the wings from which the sounds are produced. The action of the escapement produces the familiar ticking sound of clocks. The higher-frequency components of the songs of twelve species of cricket were analysed after removing the dominant low-frequency components and amplifying the remaining higher-frequency components. In normal song pulses of all species, the higher-frequency components showed a close phase-locking to the waveform of the dominant frequency, but the amplitude of the higher-frequency components did not correlate with that at the dominant frequency. Anomalous pulses occurred spontaneously in the songs of several species: multimodal, interrupted or curtailed pulses are described. In all of these, the anomalous pulse envelope was associated with changes in the amplitude and/or instantaneous frequency of the higher-frequency components of the sound. A model of the escapement suggests that the frequency of the residual components of the song depends on the symmetry of action of the plectrum on the teeth of the file.

}, keywords = {animal vocalization, animal wings, Animals, escape reaction, Gryllidae, species specificity}, issn = {0022-0949}, author = {H. C. Bennet-Clark and Winston J. Bailey} } @article {47861, title = {The control of carrier frequency in cricket calls: a refutation of the subalar-tegminal resonance/auditory feedback model.}, journal = {J Exp Biol}, volume = {203}, year = {2000}, month = {2000 Feb}, pages = {585-96}, abstract = {

The subalar-tegminal resonance/auditory feedback hypothesis attempts to explain how crickets control the carrier frequency (f(C)), the loudness and the spectral purity of their calls. This model contrasts with the \&$\#$39;clockwork cricket\&$\#$39; or escapement model by proposing that f(C) is not controlled by the resonance of the cricket\&$\#$39;s radiators (the harps) but is instead controlled neurally. It suggests that crickets are capable of driving their harps to vibrate at any frequency and that they use a tunable Helmholtz-like resonator consisting of the tegmina and the air within the subalar space to amplify and filter the f(C). This model predicts that f(C) is variable, that call loudness is related to tegminal position (and subalar volume) and that low-density gases should cause f(C) to increase. In Anurogryllus arboreus, f(C) is not constant and varied by as much as 0.8 \% between pulses. Within each sound pulse, the average f(C) typically decreased from the first to the last third of a sound pulse by 9 \%. When crickets called in a mixture of heliox and air, f(C) increased 1.07- to 1.14-fold above the value in air. However, if the subalar space were part of a Helmholtz-like resonator, then its resonant frequency should have increased by 40-50 \%. Moreover, similar increases occurred in species that lack a subalar space (oecanthines). Experimental reduction of the subalar volume of singing crickets resulted neither in a change in f(C) nor in a change in loudness. Nor did crickets attempt to restore the subalar volume to its original value. These results disprove the presence of a subalar-tegminal resonator. The free resonance of freshly excised Gryllus rubens tegmina shifted by 1.09-fold when moved between air and a mixture of helium and air. Auditory feedback cannot be the cause of this shift, which is similar to the f(C) shifts in intact individuals of other species. Calculations show that the harp is 3.9-1.8 times more massive than the air that moves en masse with the vibrating harps. Replacing air with heliox-air lowers the mass of the vibrating system sufficiently to account for the f(C) shifts. These results re-affirm the \&$\#$39;clockwork cricket\&$\#$39; (escapement) hypothesis. However, as realized by others, the harps should be viewed as narrow-band variable-frequency oscillators whose tuning may be controlled by factors that vary the effective mass.

}, keywords = {acoustic stimulation, animal vocalization, Animals, biological models, feedback, Gryllidae, male, vibration}, issn = {0022-0949}, author = {Prestwich, K N and Lenihan, K M and Martin, D M} } @article {17207, title = {Acoustics of a small Australian burrowing cricket: the control of low-frequency pure-tone songs.}, journal = {J Exp Biol}, volume = {204}, year = {2001}, month = {2001 Aug}, pages = {2827-41}, abstract = {

For most insects, size determines the call frequency. This paper describes the acoustics of a small brachypterous cricket (Rufocephalus sp.; body length 9.6 mm) producing a call with a carrier frequency of approximately 3.2 kHz from a subterranean burrow. Crickets such as Gryllus campestris are approximately twice this length and produce a call frequency close to 5 kHz. The burrow of Rufocephalus opens via a small hole with a diameter of 3.2 mm. The neck of the hole at approximately 1.4 mm depth opens to a vertical two-part burrow with an upper vase-shaped chamber 16.1 mm in height with a diameter of 9.4 mm. This top chamber connects via a 6.4mm high (diameter 5.2 mm) neck to a more irregular chamber approximately 18 mm high with a width of approximately 11 mm. The walls of the top chamber neck and of the upper part of the lower chamber are smooth and appear to be sealed with saliva. The song has a mean centre frequency of 3.2 kHz and is made up of variable-length trills of pulses of mean duration 15.8 ms. Many song pulses had smooth envelopes and their frequency did not vary by more than +/-40Hz from the centre frequency, with a relative bandwidth Q-3dB of over 50. Other pulses showed considerable amplitude and frequency modulation within the pulse. When driven by external sound, burrows resonated at a mean frequency of 3.5 kHz with a mean quality factor Q of 7.4. Natural-size model burrows resonated at similar frequencies with similar Q values. One cricket, which had previously called from its own burrow at 2.95 kHz, sang at 3.27 kHz from a burrow that resonated at the same frequency. Life-size model burrows driven by external sound resonated at similar frequencies to the actual burrows; models three times life size resonated at one-third of this frequency. In all models, the sound pressure was more-or-less constant throughout the top chamber but fell rapidly in the neck of the burrow; the phase of the sound was effectively constant in the top chamber and neck and fell through approximately 180 degrees in passing from the neck into the lower chamber. A numerical model of the sound flow from region to region gave essentially similar results. A resonant electrical model fed from a high-impedance source with discrete tone bursts at different frequencies showed similar amplitude and frequency modulation to the various types of song pulses that were observed. It is suggested that the high purity of the songs results from close entrainment of the sound-producing mechanism of the insect\&$\#$39;s wings to the sharply resonant burrow.

}, keywords = {acoustics, animal vocalization, Animals, Australia, environment, Gryllidae}, issn = {0022-0949}, url = {http://jeb.biologists.org/content/204/16/2827.long}, author = {Winston J. Bailey and H. C. Bennet-Clark and Fletcher, N H} }