02184nas a2200181 4500008004100000245009100041210006900132520157400201653002501775653002501800653001301825653002201838653001401860653002401874100002501898700002401923856005501947 2020 eng d00aSong-type switching rate in the chaffinch carries a message during simulated intrusion0 aSongtype switching rate in the chaffinch carries a message durin3 a

Birds communicate their motivation and willingness to escalate a territorial conflict with a variety of agonistic signals. One of these, song-type switching, has been suggested to be a conventional signal in male–male interactions. However, this behavior does not show a consistent pattern across species. In this study, we asked whether variation in song-switching rate carries a message for song receivers among territorial chaffinches, Fringilla coelebs. Chaffinch song is well described, but only a few studies have focused on the communicative function of song-type switching or bout duration. Using data from playback experiments, we show here that variation in song-type switching rate affects the response of chaffinches. In response to the low switching rate treatment, territorial males began to sing later, produced fewer songs and more rain calls, decreased flight intensity, and spent more time close to the speaker than during playback of songs with a high switching rate. Our results provide strong evidence that the song-type switching rate is an agonistic signal in the chaffinch and that territorial males exhibit a stronger response toward rivals that sing with a lower song-type switching rate. A secondary purpose of our study was to determine the receivers’ response with respect to their own song rate and song repertoire. We found that the reaction of tested males was correlated with their own spontaneous song rate. This implies that a male’s response to stimuli may be predicted on the basis of his own song output.

10aAggressive signaling10aanimal communication10abirdsong10aFringilla coelebs10asong rate10aSong-type switching1 aDeoniziak, Krzysztof1 aOsiejuk, Tomasz, S. uhttp://link.springer.com/10.1007/s00265-020-2825-202685nas a2200229 4500008004100000245008600041210006900127260001600196300001400212490000700226520197600233653002502209653001902234653002502253653002002278653002202298653001902320100001602339700002002355700002702375856005302402 2014 eng d00aSensory evolution of hearing in tettigoniids with differing communication systems0 aSensory evolution of hearing in tettigoniids with differing comm cJan-01-2014 a200 - 2130 v273 a

In Tettigoniidae (Orthoptera: Ensifera), hearing organs are essential in mate detection. Male tettigoniids usually produce calling songs by tegminal stridu- lation, whereas females approach the males phonotactically. This unidirec- tional communication system is the most common one among tettigoniids. In several tettigoniid lineages, females have evolved acoustic replies to the male calling song which constitutes a bidirectional communication system. The genus Poecilimon (Tettigoniidae: Phaneropterinae) is of special interest because the ancestral state of bidirectional communication, with calling males and responding females, has been reversed repeatedly to unidirec- tional communication. Acoustic communication is mediated by hearing organs that are adapted to the conspecific signals. Therefore, we analyse the auditory system in the Tettigoniidae genus Poecilimon for functional adapta- tions in three characteristics: (i) dimension of sound-receiving structures (tympanum and acoustic spiracle), (ii) number of auditory sensilla and (iii) hearing sensitivity. Profound differences in the auditory system correlate with uni- or bidirectional communication. Among the sound-receiving structures, the tympana scale with body size, whereas the acoustic spiracle, the major sound input structure, was drastically reduced in unidirectional communicating species. In the unidirectional P. ampliatus group, auditory sensilla are severely reduced in numbers, but not in the unidirectional P. propinquus group. Within the P. ampliatus group, the number of auditory sensilla is further reduced in P. intermedius which lost acoustic signalling due to parthenogenesis. The auditory sensitivity correlated with the size of the acoustic spiracle, as hearing sensitivity was better with larger spiracles, espe- cially in the ultrasonic range. Our results show a significant reduction in auditory structures, shaped by the differing sex roles during mate detection.

10aanimal communication10ainsect hearing10aregressive evolution10asensory ecology10asensory evolution10atympanal organ1 aStrauß, J.1 aLehmann, A., W.1 aLehmann, Gerlind, U.C. uhttp://doi.wiley.com/10.1111/jeb.2014.27.issue-102270nas a2200169 4500008004100000245012300041210006900164520159200233653002501825653001701850653001801867653001401885100002001899700002001919700002301939856013801962 1997 eng d00aSound Production and Reproductive Ecology of Strongly Acoustic Fish in Africa: Pollimyrus isidori, Mormyridae0 aSound Production and Reproductive Ecology of Strongly Acoustic F3 a

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.

10aanimal communication10abioacoustics10aelectric fish10amigration1 aBenech, Vincent1 aJacob, Philippe1 aCrawford, John, D. uhttps://brill.com/view/journals/beh/134/9-10/article-p677_3.xmlhttps://data.brill.com/files/journals/1568539x_134_09-10_s003_text.pdf02516nas a2200217 4500008004100000245010300041210006900144260001600213490000700229520180700236653002502043653002402068653001302092653001402105653002202119653001802141653001702159100002502176700002402201856007302225 2019 eng d00aHabitat-related differences in song structure and complexity in a songbird with a large repertoire0 aHabitatrelated differences in song structure and complexity in a cJan-12-20190 v193 a

Background

Urbanisation has been shown to influence many aspects of animal vocal communication. Much attention has been paid to anthropogenic noise, which is often described as one of the most challenging disturbances for urban dwellers. While a large body of literature describes associations between vocal behavior of avian populations and background noise level, most of these studies were conducted on species with relatively simple songs and small repertoire sizes. This study focuses on the song thrush, Turdus philomelos, a common Eurasian songbird with a complex singing style and large syllable repertoire. Our objective was to determine whether frequency, repertoire and temporal organisation of song parameters vary between birds inhabiting urban and adjacent forest habitats in which ambient noise levels differ.

Results

Songs of urban males were found to be more complex than in conspecifics from natural forest populations. Urban dwellers possessed greater syllable repertoires and repeated syllable sequences more often. In addition, they used a smaller proportion of whistles and a higher proportion of twitter syllables when singing compared to the nonurban males. Moreover, we found significant differences in the minimum and peak frequency of the whistle syllable between studied populations.

Conclusions

These findings may be an example of adaptation of acoustic communication in noisy urban environments, but we also discuss other possible explanations. We emphasize the need for further investigation into the relationships between birdsong and habitat characteristics, male quality, population density and ambient noise level in populations occupying urban and nonurban habitats.

10aanimal communication10aanthropogenic noise10abirdsong10asongbirds10aTurdus philomelos10aUrban ecology10aurbanisation1 aDeoniziak, Krzysztof1 aOsiejuk, Tomasz, S. uhttps://bmcecol.biomedcentral.com/articles/10.1186/s12898-019-0255-702429nas a2200253 4500008004100000245012300041210006900164260001600233300001400249490000800263520160100271653002601872653002501898653003401923653002201957653001501979100002001994700002702014700002302041700001702064700002402081700001502105856005502120 2018 eng d00aQuiet violence: Savannah Sparrows respond to playback-simulated rivals using low-amplitude songs as aggressive signals0 aQuiet violence Savannah Sparrows respond to playbacksimulated ri cJan-10-2018 a724 - 7320 v1243 a

When animals compete over resources such as breeding territories, they often use signals to communicate their aggressive intentions. By studying which signals are associated with aggressive interactions, we gain a deeper appreciation of animal behaviour. We studied aggressive signalling in male Savannah Sparrows, Passerculus sandwichensis, focusing on signals that precede physical attack against territorial intruders. We simulated intruders using song playback and taxidermic models, and we determined which behaviours were associated with physical attack. Previous studies that have used this approach suggest that many species produce songs of dramatically lower amplitude, or “soft songs,” as signals of aggressive intention. Savannah Sparrows, however, are not known to produce soft songs, and therefore, they provided an interesting system for testing signals that predict attack. Of 93 playback subjects, 23 males attacked the simulated intruder and 70 did not. To our surprise, Savannah Sparrows produced soft songs, and the number of soft songs was a significant predictor of attack on the simulated intruder. Birds also showed a nonsignificant tendency to produce more “chip” calls prior to attack on the simulated intruder, whereas three other measured behaviours (aggressive calls, wing waving and passes over the model) did not predict attack. Our study contributes to the growing body of research on aggressive territorial signals and reveals that soft song is an even more widespread signal of aggression in songbirds than previously recognized.

10aaggressive signalling10aanimal communication10alow‐amplitude vocalizations10aSavannah Sparrows10asoft songs1 aMoran, Ines, G.1 aDoucet, Stéphanie, M.1 aNewman, Amy, E. M.1 aNorris, Ryan1 aMennill, Daniel, J.1 aKoenig, W. uhttp://doi.wiley.com/10.1111/eth.2018.124.issue-1002522nas a2200253 4500008004100000022001300041245008400054210006900138260001600207300001100223490000800234520175500242653001801997653002502015653002302040653003702063653001902100653001702119100001502136700002002151700001502171700001602186856006602202 2017 eng d a0003347200aMale hyraxes increase countersinging as strangers become ‘nasty neighbours’0 aMale hyraxes increase countersinging as strangers become nasty n cJan-12-2017 a9 - 140 v1343 a

Many territorial animals interact less aggressively with neighbours than with strangers, a phenomenon known as the ‘dear enemy’ effect, although some species show the opposite behaviour. Rock hyraxes, Procavia capensis, are social mammals that communicate via a rich acoustic repertoire. Male hyraxes produce elaborate advertisement calls (i.e. songs) both spontaneously and in response to occasional attention-grabbing events (e.g. pup screams, agonistic interaction), as well as to conspecific male songs. When replying to conspecific songs, male hyraxes tend to respond more to familiar males than to strangers, reflecting the ‘nasty neighbour’ effect. Our study relates to the general question of why some species respond aggressively towards neighbours, while others are more aggressive towards strangers. We hypothesized that male hyraxes eventually familiarize themselves with a stranger, subsequently perceiving its intentions as highly threatening and deserving of a vocal response. To simulate the presence of a stranger in the area we exposed wild hyrax groups to playbacks of natural songs of un- familiar hyraxes. Male rock hyraxes became more likely to reply to a stranger's song over time, but this was independent of the number of times they heard the song. This suggests that either (1) the threat presented by a stranger increases when it is no longer perceived as transient or (2) because listeners do not physically encounter the stranger, they perceive replying aggressively as a low-risk response. Our work implies that species may demonstrate a range of condition-dependent behaviours instead of a dichotomy between the ‘nasty neighbour’ and ‘dear enemy’ strategies.

10aadvertisement10aanimal communication10afloating territory10aneighbour-stranger relationships10asocial mammals10avocalization1 aGoll, Yael1 aDemartsev, Vlad1 aKoren, Lee1 aGeffen, Eli uhttp://linkinghub.elsevier.com/retrieve/pii/S000334721730324X04720nas a2200205 4500008004100000022001400041245007600055210006900131260001300200300001200213490000800225520411800233653002504351653001704376653001204393653001404405653002404419100002504443856004604468 2003 eng d a0022-094900aWing resonances in the Australian field cricket Teleogryllus oceanicus.0 aWing resonances in the Australian field cricket Teleogryllus oce c2003 May a1479-960 v2063 a

The anatomy and mechanics of the fore-wings of the Australian cricket Teleogryllus oceanicus were examined to study how resonances of the wings were excited, to model the interactions between the two wings during sound production, to account for the frequency changes that occur within the pulses and to determine the variation in sound amplitude during the pulses. Sound is produced after raising the wings by closing the right wing over the left; the plectrum of the left wing engages and releases teeth on the file on the underside of the right wing. The mean number of teeth on the right file is 252; the teeth are more closely spaced in the posterior part of the file, which is engaged at the start of the song pulses. The anterior part of the file is separated from the base of the harp by a short flexible region. The dorsal field of the wing, in which the harp is situated, is largely mechanically isolated from the driving veins of the lateral field, except for a cross vein at the apex of the harp. The harps of the two wings did not differ significantly in area but the plectrum of the left wing was significantly longer and wider than that of the right wing. The posterior edge of the plectrum has a radius of approximately 0.5 micro m, which allows it to engage the 20 micro m-tall teeth of the file. The plectrum is separated from the wing by a 0.5 micro m-thick crescent that allows it to twist lengthways and thus disengage the file teeth. The sigmoid shape of the file allows the plectrum to engage teeth over most of the length of the file. The calling song of T. oceanicus consists of a chirp of four similar pulses followed by a trill of pairs of pulses. The dominant frequency of all pulses is approximately 4.8 kHz but cycle-by-cycle analysis suggests that the different types of pulse are produced by wing-closing movements through different arcs. Free resonances of the left wing occurred at 4.56 kHz [quality factor (Q)=25.1] and of the right wing at 4.21 kHz (Q=23.9). Driven by loud sound, maximum vibration of the harp was seen at approximately 4.5 kHz; at lower sound levels, the vibration was confined to the cross-veins of the harp that extend distally from the file. Resonances of the left wing driven by vibration of the same wing, either at the plectrum or on the anal area, occurred at similar frequencies to those of the songs and had similar Qs but were approximately anti-phase, demonstrating that movement of the plectrum (e.g. by the file teeth) causes an opposite movement of the harp. When the right wing was driven directly on the file, the resonant frequency was 5.88 kHz but, when driven on the file via a length of the left file and the left plectrum, it was 4.83 kHz. The amplitude of the vibration increased from the posterior end of the file to the middle then fell towards the anterior end of the file. Pushing a left plectrum across the middle of the right file produced trains of damped sound pulses at 4.82 kHz (Q=23.4). Clicks excited from the anterior end of the file had lower frequencies. The resonances excited from both the left wing via its plectrum and from the right wing when driven via the left plectrum were similar in frequency to that of the song. The resonance of the dorsal field persisted after ablation of the harp but the mean resonant frequency increased 1.12-fold with a similar Q to the intact wing. Droplets of water on the distal end of the harp or proximal part of the dorsal field raised the resonant frequency. The resonant frequency was lowered by the addition of weights to the harp or the file; the factor of the decrease suggested that the mass of the resonant system was approximately 1.4 mg, which accords with the mass of the harp plus file plus anal area of the wing (left wing, 1.27 mg; right wing, 1.15 mg) but is far heavier than the harp (0.22 mg). An earlier suggestion that the harp is the resonator is not supported; instead, it is proposed that the major elastic component of the resonant system is the file plus 1st anal vein and that the mass component is the combined mass of the file, anal area and harp.

10aanimal communication10aanimal wings10aAnimals10aGryllidae10asound spectrography1 aBennet-Clark, H., C. uhttps://bio.acousti.ca/zh-hans/node/17206