@article {58377, title = {Female house crickets,Acheta domesticus, prefer the chirps of large males}, year = {1997}, abstract = {

This study demonstrates that invertebrate acoustic signals can provide information about male phenotypic attributes, and that females can use this acoustic information in mate choice to select a phenotypically superior mate. I investigated the relationships between a male acoustic sexual signal, the phenotype of the signaller, and the female response to signal variation. I recorded and analysed the calling songs of male house crickets,Acheta domesticus. The analyses showed that chirps convey information about male size. With the exception of amplitude, the mean number of pulses per chirp was the best predictor of male size. I performed a laboratory tape-playback experiment to determine female preference during phonotaxis. Females preferred tapes playing the chirps of large males, specifically chirps with a greater number of pulses per chirp. Selection on the female preference is discussed.

}, doi = {10.1006/anbe.1997.0584}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0003347297905844https://api.elsevier.com/content/article/PII:S0003347297905844?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0003347297905844?httpAccept=text/plain}, author = {GRAY, DAVID A} } @article {58376, title = {Costs and benefits of mate choice in the lek-breeding reed frog,Hyperolius marmoratus}, year = {1997}, abstract = {

Direct benefits to females of choosing mates have recently been suggested to play a role in the evolution of female preferences even in non-resource-based mating systems. Direct benefits affect the fecundity or survival of females whereas females gain indirectly from being choosy by passing on good genes to offspring or by producing sons that are themselves more attractive to females. I investigated two potential direct benefits that females gain from being choosy in the lek-breeding painted reed frog, Hyperolius marmoratus broadleyi: assurance of fertilization and reduction in search costs. Males did not differ in their fertilization rates, indicating that choosy females did not benefit by gaining higher rates of fertilization. However, costs of mate searching were high due to predation risk by brown water snakes, Lycodonomorphus rufulus, at the breeding site. Small natural choruses were monitored using an acoustic localization technique based on the measurement of arrival time differences of a male\&$\#$39;s signal at an array of microphones. Females preferred males that were near to their release site and that called at high rates. These preferences were corroborated experimentally in two-choice arena trials and are consistent with the notion that females should reduce search time under high predatory pressure. Because sampling costs are high, females are selected to reduce search time and males are predicted to call so that females can locate them easily. High sampling costs also make direct selection on female preferences a plausible solution to the lek paradox.

}, doi = {10.1006/anbe.1996.0427}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0003347296904273https://api.elsevier.com/content/article/PII:S0003347296904273?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0003347296904273?httpAccept=text/plain}, author = {GRAFE, T.ULMAR} } @article {58236, title = {Vocalisations of the Marbled Frogmouth II: An Assessment of Vocal Individuality as a Potential Census Technique}, year = {1997}, abstract = {

Using recorded vocalisations of Marbled Frog- mouths Podargus ocellatus from southern Queensland, an assessment was undertaken of the extent of vocal individual- ity and its potential as a census technique. The \‘Kerloo\’, an apparently territorial vocalisation, was selected as being most likely to demonstrate individuality. Qualitative com- parisons of spectrograms were abandoned due to the inabil- ity of workers to distinguish between birds. A detailed quan- titative analysis employed 11 measures taken from on-screen
spectrograms. Discriminant Function Analyses were able to separate almost all individuals reliably for both males and females. Three variables were of particular importance in the functions derived for both sexes: the duration of the Kerloo; the frequency range; and the number of elements included in a call. The ability of the technique to separate individual birds was high and its applicability to field studies appears possible provided workers are proficient with the analyses and that the behavioural context of the calls is appreciated.

}, doi = {10.1071/MU97043}, url = {https://www.tandfonline.com/doi/full/10.1071/MU97043https://www.tandfonline.com/doi/pdf/10.1071/MU97043}, author = {Jones, Darryl N. and Smith, Geoffrey C.} } @article {58053, title = {A New Examination of Echolocation Calls of Some Neotropical Bats (Emballonuridae and Mormoopidae)}, journal = {Journal of MammalogyJournal of Mammalogy}, volume = {87}, number = {3}, year = {1997}, pages = {954-963}, abstract = {

In northwestern Belize, two emballonurids Rhynchonycteris naso and Saccopteryx bilineata) and three mormoopids Pteronotus parnellii, P. davyi, and P. personatus) were examined acoustically with the Anabat II bat detector and associated analysis system. R. naso used calls consisting of a short constant frequency CF) at 47 kHz and concave downward frequency modulated FM) sweep to about 40 kHz with two strong harmonics. Echolocation sequences of S. bilineata revealed a paired cadence of calls. Both signals in a pair slowly increased in frequency, forming a quasi-CF QCF) component and terminated with a short, downward FM sweep. The initial call of a pair ranged from 44.5 to 46.6 kHz and the second ranged from 46.6 to 48.7 kHz. P. parnellii used a long CF call at 63.5 kHz, with a terminal downward FM sweep to about 54.5 kHz. P. davyi produced calls with an initial short CF at 68.1 kHz, a downward FM sweep, and a terminal short CF at 58.0 kHz. P. personatus emitted calls similar in shape to P. davyi, with the initial CF at 83.0 kHz and the terminal CF at about 68.0 kHz. Previous descriptions of echolocation calls for these species compare favorably with those obtained in this study, but the Anabat equipment generally revealed more variation and detail than previously described. The echolocation calls described in this study provide precise vocal signatures for the accurate identification of free-flying individuals of the species studied.

}, keywords = {Anabat, bats, echolocation, Pteronotus davyi, Pteronotus parnellii, Pteronotus personatus, Rhynchonycteris naso, Saccopteryx bilineata, vocal signatures}, author = {O{\textquoteright}Farrell, Michael J. and Miller, Bruce W.} } @article {57916, title = {Sound Production and Reproductive Ecology of Strongly Acoustic Fish in Africa: Pollimyrus isidori, Mormyridae}, year = {1997}, abstract = {

We have studied the reproductive ecology and bioacoustic signals of weakly electric mormyrid fish in Africa in order to discover the natural conditions under which acoustic signals are used and to gain insight into the evolution of their acoustic behaviour and hearing. Pollimyrus isidori migrated from a tributary of the Niger River (Mali) into a shallow (2- 3 m) flood plain during the onset of the flooding seasons (August, 1991 and 1994). The\ fish were fully primed for reproduction upon entering the plain, females were significantly larger than males, and the sex ratio was skewed toward males (about 2 males per female). Males established territories (d \≈ 1 m) within the roots of floating rafts of grasses, about 0.5 m below the water surface. Males produced conspicuous acoustic displays consisting of Grunts and Moans during the night (130 dB peak re 1 \μLPaat approximately 10 cm). These sounds had a fundamental of 340 Hz, but the band-width of the grunt extended to over 3 kHz. Experiments at the field site with captive animals showed that male sound production was stimulated by the presence of conspecific females. The P. isidori repertoire included 3 additional sounds. Analysis of environmental noise showed that these communication sounds fall within a distinct spectral window, thereby minimizing potential interference from other aquatic animals and abiotic noise sources. Waveform analyses showed that the sounds remained coherent over short distances (0.5 m) but lost amplitude more rapidly than would be predicted in a deep water free-field.

}, keywords = {animal communication, bioacoustics, electric fish, migration}, doi = {10.1163/156853997X00034}, url = {https://brill.com/view/journals/beh/134/9-10/article-p677_3.xmlhttps://data.brill.com/files/journals/1568539x_134_09-10_s003_text.pdf}, author = {Benech, Vincent and Jacob, Philippe and Crawford, John D.} } @article {52755, title = {The energetic cost of calling in the variable field cricket, Gryllus lineaticeps}, journal = {Physiological Entomology}, volume = {22}, year = {1997}, month = {Jan-09-1997}, pages = {286 - 290}, abstract = {

Female preferences for conspicuous male calls have been documented in many groups. However, relatively few studies have examined the metabolic costs associated with the production of call types preferred by females. We measured the oxygen consumption of calling male Gryllus lineaticeps St\ål crickets using closed chamber respirometry. Calling song was recorded concurrently. The average increase in mass-specific oxygen consumption during calling was 2.7 times basal rates of oxygen consumption, and calling males consumed approximately 1.2ml O2g-lh-1. Oxygen consumption increased with increasing chirp rate and pulse duration, but not with increasing chirp duration. Females of this species prefer higher chirp rates, thus some call types that increase the male\&$\#$39;s attractiveness to females require more metabolic energy to produce.

}, keywords = {female preference, Field cricket, Gryllus lineaticeps, metabolic cost}, issn = {0307-6962}, doi = {10.1111/j.1365-3032.1997.tb01170.x}, url = {http://doi.wiley.com/10.1111/j.1365-3032.1997.tb01170.xhttps://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111\%2Fj.1365-3032.1997.tb01170.x}, author = {W. Wyatt Hoback and William E. Wagner} } @article {40443, title = {The World{\textquoteright}s Most Unusual Gryllacridid (Orthoptera: Gryllacrididae)}, journal = {Journal of Orthoptera Research}, volume = {6}, year = {1997}, pages = {57-68}, chapter = {57}, abstract = {

Gryllacridid behavior and morphology is referred to an unusual Raspy Cricket from south-east Queensland is described in a new genus and species, Urogryllacris gwinganna gen. \& sp. nov. The species is unique in the Gryllacrididae in having an extraordinarily developed male subgenital plate which terminates in an elongate whip-like structure. The new genus and species are described with emphasis given to the proventriculus, the male subgenital plate and the egg. A mating sequence is described with a discussion concerning the possible function of the peculiar subgenital plate.

}, url = { http://www.jstor.org/stable/3503536}, author = {D. C. F. Rentz} } @article {40433, title = {Sound production in primitive Orthoptera from Western Australia: sounds used in defence and social communication in Ametrus sp. and Hadrogryllacris sp. (Gryllacrididae: Orthoptera)}, journal = {Journal of Natural History}, volume = {31}, year = {1997}, month = {Jan-07-1997}, pages = {1127 - 1141}, abstract = {

Sound production in two undescribed species of Gryllacrididae belonging to the genus Ametrus sp. and Hadrogryllacris sp. takes the form of defensive stridulation and intra-specific signalling by drumming on the substrate. Defensive stridulation is produced as part of an elaborate visual display, by femoro-tergal stridulation. Two rows of spines on abdominal tergites II and III of both species are rubbed by an elongate area of tubercules on the inner femoral surface of the hind legs. Analysis showed that the motion of the leg relative to the abdomen involves a complex counter-rotation of the leg between leg and abdomen. The defensive display may be performed in day light. Social signalling in both species occurs after dark, and involves drumming on the substrate by both hind legs in loose synchrony. Drumming is rhythmic and species\&$\#$39; specific. Males respond to playback calls and females duet with males. The evolution of this calling behaviour is discussed and comparisons are made with the other primitive ensiferan family known to produce both tergo-abdominal defensive stridulation and femoral drumming behaviour, the Stenopelmatidae.

}, keywords = {defence, duetting, social communication, sound production, substrate vibration}, issn = {0022-2933}, doi = {10.1080/00222939700770591}, url = {http://www.tandfonline.com/doi/abs/10.1080/00222939700770591}, author = {Field, L.H. and Winston J. Bailey} } @article {20902, title = {Sexual signalling in bladder grasshoppers: tactical design for maximizing calling range.}, journal = {J Exp Biol}, volume = {200}, year = {1997}, month = {1997 Oct}, pages = {2597-608}, abstract = {

Pair formation in the bladder grasshopper (Bullacris membracioides) is by duetting and male phonotaxis. Low-frequency stridulatory signals are emitted by an abdominal resonator in the male and are answered by females using a species-specific time delay. Acoustic transmission in the natural environment was studied using playback of sexual signals over distances of 450m under two atmospheric conditions (day and night). Upward-refracting sound conditions and a sound shadow zone beyond approximately 50m prevailed during the day. Acoustic enhancement was demonstrated at night when downward-refracting temperature inversions created a tunnel effect with sound caught between the ground and zones of different temperatures. Transmission conditions are almost ideal at night when the species actually calls; calling distances of 150m for the male signal in the afternoon increased to 1.5-1.9km at night, arguably the largest calling distance yet reported for insects. In contrast, female calls transmit over a maximum of 50m, signifying a marked discrepancy in the active space of sex-specific signals. Transmission distance may, however, be profoundly affected by levels of masking noise. Adaptations to increase the signal range may variously be found in the signal itself, in behaviour patterns or in the sensory system. Here we demonstrate aspects of the first two types of adaptation in the sexual signalling system of a grasshopper in which maximizing the calling range appears to be the major selection pressure, with lesser effects imposed by inter- and intraspecific pressures and by the transmission channel.

}, keywords = {animal sexual behaviour, Animals, female, grasshoppers, male}, issn = {0022-0949}, author = {Moira J. van Staaden and Heiner R{\"o}mer} } @article {17210, title = {Tymbal mechanics and the control of song frequency in the cicada Cyclochila australasiae}, journal = {J Exp Biol}, volume = {200}, year = {1997}, month = {1997}, pages = {1681-94}, abstract = {

The anatomy of the tymbal of Cyclochila australasiae was re-described and the mass of the tymbal plate, ribs and resilin pad was measured. The four ribs of the tymbal buckle inwards in sequence from posterior to anterior. Sound pulses were produced by pulling the tymbal apodeme to cause the tymbal to buckle inwards. A train of four sound pulses, each corresponding to the inward buckling of one rib, could be produced by each inward pull of the apodeme, followed by a single pulse as the tymbal buckled outwards after the release of the apodeme. Each preparation produced a consistent sequence of pulses. Each of the pulses produced had its maximum amplitude during the first cycle of vibration. The waveform started with an initial inward-going rarefaction followed by a larger outward compression, followed by an approximately exponential decay, as is typical of a resonant system. The mean dominant frequencies of the pulses produced during the inward movement were 4.37, 4.19, 3.92 and 3.17 kHz respectively. The pulse produced during the outward movement had a mean resonant frequency of 6.54 kHz. This suggests that the mass-to-stiffness ratio that determines the resonant frequencies of the various pulses differs from pulse to pulse. If succeeding pulses followed rapidly, the next pulse tended to start on the inward-going half-cycle of its predecessor and to produce a coherent waveform. Coherence was lost if the preceding pulse had decayed to below approximately one-tenth of its peak amplitude. When the tymbal plate was loaded by a 380 \µg wire weight, the resonant frequency of all sound pulses was reduced. Pulses produced later in the inward buckling sequence were less affected by the loading than earlier ones. This suggests that the effective mass determining the resonance in the later pulses is greater than that in the earlier pulses. The frequency of the pulses produced in the outward movement was affected most, suggesting that the mass involved was less than that in any of the pulses produced by the inward movement. The quality factor, Q, of the pulses produced by the inward buckling of the unloaded tymbal was approximately 10. For the outward buckling, Q was approximately 6. The Q of loaded tymbals was higher than than that of unloaded tymbals. The Q of the resonances varied approximately as the reciprocal of the resonant frequency. Experimental removal of parts of the tymbal showed that the thick dorsal resilin pad was an important elastic determinant of the resonant frequency, but that the mass and elasticity of the tymbal ribs were also determinants of the resonant frequency. The major element of mass is the tymbal plate. The integrity of the tymbal ribs was essential if the buckling movement were to occur. The force required to cause inward buckling of the tymbal was approximately 0.25 N. The force required to hold the tymbal in the buckled-in position was approximately 0.05 N. This asymmetry in the tymbal compliance, together with the different masses involved in inward and outward buckling, may account for the difference between the resonant frequencies of the inward-going and outward-going clicks. The tymbal appears to act as an energy storage mechanism that releases energy as the tymbal ribs buckle inwards in sequence. Each pulse provides a large initial impulse to the abdominal resonator, followed by a sustaining resonant vibration at, or close to, the song frequency. Subsequent pulses maintain the coherent resonance of the song pulse.

}, issn = {1477-9145}, url = {http://jeb.biologists.org/content/200/11/1681.long}, author = {H. C. Bennet-Clark} } @mastersthesis {11959, title = {Incipient Speciation In The Meadow Grasshopper, Chorthippus parallelus (Orthoptera: Acrididae).}, volume = {PhD}, year = {1997}, school = {University of East Anglia}, address = {Norwich, UK}, abstract = {

This thesis examines the evolutionary divergence between northern European and Italian populations of Chorthippus parallelus. Several differing approaches were taken, which identified the inception of various components of the speciation process between these parapatric populations which meet in the Alps.

Firstly, partial post-zygotic reproductive isolation was demonstrated using hybrid crosses. The male hybrid offspring of both reciprocal crosses were sterile, displaying severe testicular dysfunction, while the female hybrids showed no deleterious effects of hybridisation. In this grasshopper the males are the heterogametic sex, possessing a single X chromosome, and so this pattern of hybrid sterility conforms to Haldane{\textquoteright}s rule. Secondly, investigation of the calling song of the male grasshopper, a component of the mate recognition system, suggested the presence of pre-mating reproductive isolation. Males from the different races were found to sing calling song of a significantly different structure. Finally, examination of DNA sequence divergence in a mitochondrial DNA marker demonstrated Significant levels of genetic differentiation between the races. This population divergence and incipient reproductive isolation parallels that found between the north European and Iberian populations of this grasshopper, and provides further evidence that the divergent geographical races have resulted from allopatric divergence while in isolated refugial populations during the glacial periods of thePleistocene Epoch.

These approaches were repeated to investigate genetic divergence between localised populations within the Italian peninsula. No hybrid dysfunction was observed between these populations, suggesting that they are recently derived from one continuous population. This was probably the refugial population of the last ice-age. Additionally, investigation with the mtDNA marker gave preliminary evidence for population expansion from the south to the north of Italy. Interestingly, the male calling song was Significantly different in populations from the north and the south of Italy, suggesting that a component of pre-mating reproductive isolation may have evolved prior to post-mating isolation in allopatric populations of C. parallelus.

}, author = {Nicola S. Flanagan} }