02013nas a2200145 4500008004100000245011000041210006900151300001200220490000800232520152000240100002301760700002001783700001801803856004601821 2004 eng d00aTemporal Shifts in Conspicuousness: Mate Attraction Displays of the Texas Field Cricket, Gryllus texensis0 aTemporal Shifts in Conspicuousness Mate Attraction Displays of t a963-9750 v1103 a

Conspicuous mate attraction displays can simultaneously draw the attention of potential mates and predators, placing the signaller in peril of becoming prey. The balance between these countervailing forms of selection has the potential to shape mate attraction displays. Male Texas field crickets (Gryllus texensis; Orthoptera) signal acoustically to attract mates. Mating signals also attract acoustically orienting parasitoid flies (Ormia ochracea; Tachinidae). Both the abundance of female crickets and parasitoid flies fluctuates throughout the night. We show mate attraction displays exhibit diel shifts that correlate positively with expected female cricket presence and negatively with expected parasitoid fly activity. During early evening, when parasitoids are most common and mating is scarce, crickets signal less often and with reduced conspicuousness. During the second half of the evening, when sexually receptive females are abundant and parasitoids are scarce, crickets signal more often and with enhanced conspicuousness. These diel shifts in mate attraction displays do not appear to result from male crickets detecting parasitoid flies or female crickets and altering their behaviour accordingly. Males in close proximity to parasitoid flies or female crickets do not signal differently than lone males. Instead, diel pattern shifts in mate attraction displays appear to be a selective response to trade-offs between natural selection via parasitism and sexual selection via mate choice.

1 aBertram, Susan, M.1 aOrozco, Xochitl1 aBellani, Rudy uhttps://bio.acousti.ca/zh-hans/node/5845802360nas a2200205 4500008004100000245010700041210006900148260001600217300001400233490000800247520169800255653002301953653002001976653001401996653002402010100002702034700002402061700001502085856005402100 2018 eng d00aSoft songs in male ortolan buntings are used in an aggressive context but are not an aggressive signal0 aSoft songs in male ortolan buntings are used in an aggressive co cJan-08-2018 a549 - 5580 v1243 a

Many bird species produce low‐amplitude acoustic signals that have been poorly studied in comparison with loud, broadcast songs used for mate attraction and repelling rivals. In some birds, these soft signals were found to be emitted in an antagonistic context and were the most reliable predictor of a subsequent physical attack. The function of this signal is poorly understood, and several hypotheses have been proposed to explain the mechanisms and possible functions of such low‐amplitude signals. The subject of this study is the ortolan bunting, a small passerine species that produces soft songs during territorial defence. In this study, we aim to study whether the soft songs of the ortolan bunting are a signal of increased aggressiveness by testing if they meet the context, prediction and response criteria of aggressive signals. We simulated stranger male intrusion into a focal male territory with three different playback experiments. We found no significant differences in the male responses to the taxidermic model regardless of whether they were or were not producing soft songs in response. The males responded more strongly to loud songs than to soft songs during the simulated intrusions, and the males did not treat soft songs as a predictor of conflict escalation. Although soft songs clearly appeared during territorial encounters and were not present during spontaneous singing before the intrusions, our results did not support the hypothesis that soft songs indicate aggressive character. We suggest that soft songs in the ortolan bunting are intentionally used by birds to modify their intentions or target‐specific individuals within a close range.

10aAggressive signals10aortolan bunting10asoft song10aterritorial defence1 aJakubowska, Aleksandra1 aOsiejuk, Tomasz, S.1 aFusani, L. uhttp://doi.wiley.com/10.1111/eth.2018.124.issue-802388nas a2200241 4500008004100000245010700041210006900148260001600217300001400233490000800247520168200255653001401937653001101951653001801962653001201980653001301992653001102005100002102016700001802037700002002055700001702075856005402092 2018 eng d00aRavens adjust their antipredatory responses to con- and hetero-specific alarms to the perceived threat0 aRavens adjust their antipredatory responses to con and heterospe cJan-08-2018 a609 - 6160 v1243 a

Heterospecific alarm calls are typically found in situations where multiple species have a common predator. In birds, they are particularly common in mixed mixed‐species flocks. In species with highly developed social and cognitive abilities like corvids, there is the potential for differential responses to heterospecific vs. conspecific calls according to the riskiness of the habitat. We tested the responses of free‐ranging ravens (Corvus corax) to conspecific alarm calls and compared them to heterospecific alarm calls of jackdaws (Corvus monedula). We observed the proportion of ravens leaving the feeding site after the con‐ or hetero‐specific playback was presented in a situation of low threat (wild boar—Sus scrofa enclosure) and high threat of predation (wolf—Canis lupus enclosure). We show that ravens responded to conspecific calls more intensively at the wolves than at the wild boar, but the response to conspecific calls was in both enclosures stronger than to the control (great tit—Parus major song). The response to the heterospecific alarm was also stronger in the wolves’ enclosure, but it did not differ from control in the wild boar enclosure. These findings suggest that ravens are aware of the meaning of the jackdaw alarm calls, but they respond to it only in a situation of high predatory threat (wolves are present). In the wild boar enclosure, the ravens probably consider jackdaws warning against some other predator, very probably harmless to ravens. This interpretation requires further testing, as both enclosures differ also in respect to other parameters like food quality and shelter availability.

10aavoidance10acorvid10ahonest signal10ajackdaw10apredator10athreat1 aNácarová, Jana1 aVeselý, Petr1 aBugnyar, Thomas1 aTregenza, T. uhttp://doi.wiley.com/10.1111/eth.2018.124.issue-802577nas a2200157 4500008004100000245015500041210006900196260001600265300001400281490000800295520199800303100002602301700002102327700001702348856005402365 2018 eng d00aLimited flexibility in female Pacific field cricket ( Teleogryllus oceanicus) exploratory behaviors in response to perceived social environment0 aLimited flexibility in female Pacific field cricket iTeleogryllu cJan-09-2018 a650 - 6560 v1243 a

How populations adapt, or not, to rapid evolution of sexual signals has important implications for population viability, but is difficult to assess due to the paucity of examples of sexual signals evolving in real time. In Hawaiian populations of the Pacific field cricket (Teleogryllus oceanicus), selection from a deadly parasitoid fly has driven the rapid loss of a male acoustic signal, calling song, that females use to locate and evaluate potential mates. In this newly quiet environment where many males are obligately silent, how do phonotactic females find mates? Previous work has shown that the acoustic rearing environment (presence or absence of male calling song) during late juvenile stages and early adulthood exposes adaptive flexibility in locomotor behaviors of males, as well as mating behaviors in both sexes that helps facilitate the spread of silent (flatwing) males. Here, we tested whether females also show acoustically induced plasticity in walking behaviors using laboratory‐reared populations of T. oceanicus from Kauai (HI; >90% flatwings), Oahu (HI; ~50% flatwings), and Mangaia (Cook Islands; no flatwings or parasitoid fly). Though we predicted that females reared without song exposure would increase walking behaviors to facilitate mate localization when song is rare, we discovered that, unlike males, female T. oceanicus showed relatively little plasticity in exploratory behaviors in response to an acoustic rearing environment. Across all three populations, exposure to male calling song during development did not affect latency to begin walking, distance walked, or general activity of female crickets. However, females reared in the absence of song walked slower and showed a marginally non‐significant tendency to walk for longer durations of time in a novel environment than those reared in the presence of song. Overall, plasticity in female walking behaviors appears unlikely to have facilitated sexual signal loss in this species.

1 aHeinen-Kay, Justa, L.1 aStrub, Daina, B.1 aZuk, Marlene uhttp://doi.wiley.com/10.1111/eth.2018.124.issue-901255nas a2200145 4500008004100000245004800041210004800089260001600137300001400153490000800167520084400175100002001019700001601039856005401055 2018 eng d00aTree cricket baffles are manufactured tools0 aTree cricket baffles are manufactured tools cJan-09-2018 a691 - 6930 v1243 a

Tree crickets use sound to attract mates and make acoustic baffles to increase their sound production efficiency. It has been recently discovered that these insects use a flexible yet inherited behavioural programme to make acoustically optimal baffles. Whether these baffles qualify as tools, however, remains controversial. Here, baffle‐using and baffle‐making behaviours are analysed using the most current and authoritative definition of tool use. The current definition of tool use does not require the tool to be detached from the substrate and includes attached but manipulable external objects. Given this schema, tree cricket baffles, which are attached but manipulated prior to use, must be considered tools. The mode of manufacture for a baffle is “Subtract,” and the mode of use is “Drape”.

1 aMhatre, Natasha1 aBertram, S. uhttp://doi.wiley.com/10.1111/eth.2018.124.issue-902429nas 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-1002207nas a2200169 4500008004100000245012600041210006900167260001600236300001400252490000800266520162100274100002601895700002201921700002401943700001501967856005501982 2018 eng d00aAdvertising individual identity by mother and adolescent contact calls in Siberian wapiti Cervus elaphus sibiricus0 aAdvertising individual identity by mother and adolescent contact cJan-10-2018 a733 - 7420 v1243 a

Individualistic contact calls facilitate mother‐offspring reunion after separation. However, in many mammals, both the acoustic structure and individuality of contact calls differ between mother and young. In contrast, in Siberian wapiti Cervus elaphus sibiricus, contact calls are similar in the acoustics between mother and young, whereas effects of this similarity on vocal individuality were not investigated. In this study, we analyzed acoustic differences between closed‐mouth (nasal) and open‐mouth (oral) contact calls and examined individuality of the most usual oral calls of 19 Siberian wapiti (9 hinds and 10 5–6‐month adolescents) emitted in response to mother‐offspring separation. In the oral calls, the values of frequency and power variables were higher than in the nasal calls. Calls of hinds and adolescents did not differ by the maximum fundamental frequency and duration, whereas the peak frequency was higher in the young. Discriminant function analysis (DFA) based on 11 acoustic variables of oral calls accurately classified to individual 92.5% of hind calls and 96.9% of adolescent calls (chi‐square test for differences between hinds and adolescents, p = 0.19). Variables mainly contributing to vocal identity (duration, start, and maximum fundamental frequency) were the same in calls of mothers and adolescents. We conclude that similarities in the acoustics calls of mothers and adolescents mean that they do not differ in their potential for encoding individual identity, suggesting a mutual process of mother‐offspring vocal recognition in Siberian wapiti.

1 aSibiryakova, Olga, V.1 aVolodin, Ilya, A.1 aVolodina, Elena, V.1 aWright, J. uhttp://doi.wiley.com/10.1111/eth.2018.124.issue-1002713nas a2200241 4500008004100000245011600041210006900157300001400226490000800240520193100248653001402179653003302193653001002226653002302236653001402259653002802273653002002301653002402321100002102345700003402366700002502400856004602425 2018 eng d00aTestosterone pulses at the nest site modify ultrasonic vocalization types in a monogamous and territorial mouse0 aTestosterone pulses at the nest site modify ultrasonic vocalizat a804–8150 v1243 a

Modulation of baseline testosterone (T) via long‐lasting T implants alters territorial, sexual, and social behavior of animals in the field. Transient T increases occur in numerous species after social interactions, but these transient increases in T have not been manipulated in the field. In the laboratory, these T increases can influence future behavior for days, causing changes in social behavior and inducing preferences for specific locations. We manipulated transient increases in T in the field at the nests of the monogamous and territorial California mouse (Peromyscus californicus) to examine long‐term (>24 hr) changes in ultrasonic vocalizations (USVs). Males of bonded male–female dyads (=pair) were administered a T injection (vs. saline) three times over seven days and USVs of the male–female dyad were measured for three days after the last injection. At T nests, the male–female dyad produced significantly more 1SV (one call SV: an SV is a sustained vocalization that is long in duration and low in modulation) and 4SV (four call SV) type USVs than controls, but no significant changes in aggressive barks. Overall, male–female dyad mice at T nests produced a greater diversity in call types such that 1SV, 4SV, 5SV, and a complex sweep were produced at T nests but not control nests. There were significantly more USVs produced at T nests on night 2 after the final injection. There were no differences in spectral characteristics of SV calls or aggressive barks between T and control nests. The function of the changes that occurred is unknown, but is consistent with increased long‐term changes in behavioral interactions with nest mates and may reflect T‐induced conditioned place preferences to the nest site. Significantly, transient increases in T influence future acoustic communication under field conditions with competing biotic and abiotic stimuli.

10aandrogens10aconditioned place preference10afield10amale‐female dyad10apair bond10aPeromyscus californicus10asocial behavior10avocal communication1 aTimonin, Mary, E1 aKalcounis-Rueppell, Matina, C1 aMarler, Catherine, A uhttps://bio.acousti.ca/zh-hans/node/5325602747nas a2200181 4500008004100000245010100041210006900142260001600211300001400227490000800241520215200249100002102401700002502422700002402447700002402471700001502495856005502510 2017 eng d00aMale territorial aggression does not drive conformity to local vocal culture in a passerine bird0 aMale territorial aggression does not drive conformity to local v cJan-11-2017 a800 - 8100 v1233 a

In many songbird species, young individuals learn songs from neighbors and then settle nearby, thus creating neighborhoods of conformity to local vocal culture. In some species, individuals appear to postpone song learning until after dispersal, possibly to facilitate conformity to local dialects. Despite decades of study, we still lack a consensus regarding the selective pressures driving this delayed song learning. Two common hypothetical benefits to conformity, and thus delayed song learning, are rooted in territorial interactions; individuals preferentially produce local song either to avoid detection as new arrivals (deceptive mimicry) or to be more effectively recognized as conspecific territory holders. The dickcissel (Spiza americana) is an ideal species in which to study these hypotheses. Males of this species appear to delay song learning until they arrive at their first adult territory, each individual sings a single song type, and conformity to the local song culture is high. Using playback, we contradicted both of the territorial hypotheses described above; male dickcissels did not respond differentially to local vs foreign song playback treatment. We are confident in this lack of difference because dickcissels clearly responded less strongly to a third treatment, neighbor song, than to the other two treatments, demonstrating sufficient power in our experimental design (and providing the first evidence of the dear-enemy effect in dickcissels). Our results raise the question of why dickcissels respond equally aggressively to both local and foreign songs when other bird species often show reduced aggression toward foreign song. If reduced aggression to foreign song is not ubiquitous in species that achieve conformity through delayed learning, then selection from aggressive territorial interaction seems unlikely to be a general explanation for such delayed learning. Reduced aggression in response to foreign songs in other species may be due to reduced exposure to the stimulus of foreign song or to different cost-benefit trade-offs when responding to songs that deviate from the local average.

1 aParra, Marcelina1 aDalisio, Anthony, C.1 aJensen, William, E.1 aParker, Timothy, H.1 aKoenig, W. uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-1100574nas a2200145 4500008004100000245016800041210006900209260001600278300001400294490000800308100001900316700002300335700001500358856005500373 2017 eng d00aVariation in chick-a-dee calls of bridled titmice ( Baeolophus wollweberi): Frequent use of non-combinatorial calls in a combinatorial calling system0 aVariation in ichickadeei calls of bridled titmice iBaeolophus wo cJan-11-2017 a835 - 8420 v1231 aJung, Hwayoung1 aFreeberg, Todd, M.1 aKoenig, W. uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-1102237nas a2200229 4500008004100000245010100041210006900142260001600211300001400227490000800241520150700249100003101756700001801787700002201805700002001827700001901847700002301866700002301889700002501912700001501937856005501952 2017 eng d00aNegative impact of urban noise on sexual receptivity and clutch size in female domestic canaries0 aNegative impact of urban noise on sexual receptivity and clutch  cJan-11-2017 a843 - 8530 v1233 a

In oscines, male song stimulates female reproduction and females are known to adjust both their sexual preferences and their maternal investment according to song quality. Female domestic canaries are especially responsive to wide frequency bandwidth (4 kHz) male songs emitted with a high-repetition syllable rate and low minimal frequencies (1 kHz). We previously showed that low-frequency urban noise decreases female sexual responsiveness for these low-frequency songs (1–5 kHz) through auditory masking. Based on the differential allocation hypothesis, we predicted that urban noise exposure will equally affect female maternal investment. Using a crossover design, we broadcast low-frequency songs to females either in an overlapping noise condition or in an alternating noise condition. Females decreased both their sexual responsiveness and their clutch size in the overlapping noise treatment relative to the alternative noise treatment. No differences were found concerning egg size or egg composition (yolk and albumen mass, testosterone concentration). Due to our experimental design, we can exclude a general impact of noisy conditions and thereby provide evidence for a detrimental effect through masking on avian courtship and reproductive output. These results suggest that noisy conditions may also affect avian communication in outdoor conditions, which may partly explain field reports on noise-dependent breeding success and reduced breeding densities at noisy sites.

1 aAunay, Guillaume, Huet des1 aGrenna, Marco1 aSlabbekoorn, Hans1 aNicolas, Pierre1 aNagle, Laurent1 aLeboucher, Gérard1 aMalacarne, Giorgio1 aDraganoiu, Tudor, I.1 aFusani, L. uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-1102736nas a2200181 4500008004100000245007500041210006900116260001600185300001400201490000800215520216900223100002502392700002202417700002402439700002102463700001502484856005502499 2017 eng d00aGrunt to go-Vocal coordination of group movements in redfronted lemurs0 aGrunt to goVocal coordination of group movements in redfronted l cJan-12-2017 a894 - 9050 v1233 a

To remain cohesive as a group, individuals must coordinate their movements between resources. In many species, vocalisations are used in this context. While some species have specific movement calls, others use calls which are also employed in different contexts. The use of such multicontextual calls has rarely been studied quantitatively, especially during both the pre-departure and departure period associated with collective decisions. We thus investigated the use of close calls (“grunts”) for the coordination of collective movements in four groups of wild redfronted lemurs (Eulemur rufifrons) in Kirindy Forest, Western Madagascar. Group movements are started by an initiator, who moves away from the group and is joined by followers setting out in the same direction. We observed collective movements and recorded vocalisations from 18 focal individuals (54 movements recorded for followers, 21 for initiators). The grunt rate of both initiators and followers was higher in the pre-departure period than in a control context (i.e., during foraging). Initiators of collective movements grunted more often than followers in the pre-departure period as well as at individual departure. The latter difference was due to the initiators’ grunt rates increasing earlier than the followers’ and remaining at an elevated level for longer. These observations suggest that grunts serve to coordinate the departure by indicating the individual's readiness to move. The pre-departure period, in which both initiators and followers showed an elevated grunt rate, may provide the basis for a shared decision on departure time. The difference in initiator and follower call rates suggests that grunts may have a recruitment function, but playback experiments are required to test this potential function. Overall, our study describes how multicontextual close calls can function as movement calls, with changes in call rate providing a potential feedback mechanism for the timing of group movements. This study thus contributes to a more detailed understanding of the mechanisms of group coordination and collective decision-making.

1 aSperber, Anna, Lucia1 aWerner, Lynne, M.1 aKappeler, Peter, M.1 aFichtel, Claudia1 aWright, J. uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-1202500nas a2200193 4500008004100000245008100041210006900122260001600191300001400207490000800221520188400229100001802113700002102131700002202152700002902174700002802203700002002231856005502251 2017 eng d00aBottlenose dolphins that forage with artisanal fishermen whistle differently0 aBottlenose dolphins that forage with artisanal fishermen whistle cJan-12-2017 a906 - 9150 v1233 a

Acoustic communication is a taxonomically widespread phenomenon, crucial for social animals. We evaluate social sounds from bottlenose dolphins (Tursiops truncatus) of Laguna, southern Brazil, whose social structure is organized around a cooperative foraging tactic with artisanal fishermen. This tactic involves stereotyped and coordinated behaviour by dolphins and fishermen and is performed by a subset of the dolphin population, splitting it into two distinct social communities. We compared the acoustic parameters and type of whistles emitted by dolphins of the “non-cooperative” and “cooperative” communities, both during their interactions with fishermen and in times where dolphins were engaged in other types of foraging. Our findings show how dolphins’ social sounds differ between foraging tactics and social communities. The frequencies of six whistle types (ascending, descending, concave, convex, multiple, flat) were significantly dependent on tactics and communities. Ascending whistles were more common than expected during foraging without fishermen, and among dolphins of the non-cooperative community. Whistle acoustic parameters (duration, number of inclination changes and inflection points, and initial, final, maximum, minimum frequencies) also varied between social communities. In general, whistles emitted by cooperative dolphins, mainly when not interacting with fishermen, tended to be shorter, had higher frequency and more inflections than those emitted by non-cooperative dolphins. These results suggest that different whistles may convey specific information among dolphins related to foraging, which we hypothesize promote social cohesion among members of the same social community. These differences in acoustic repertoires add a new dimension of complexity to this unique human–animal interaction.

1 aRomeu, Bianca1 aCantor, Mauricio1 aBezamat, Carolina1 aSimões-Lopes, Paulo, C.1 aDaura-Jorge, Fábio, G.1 aEbensperger, L. uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-1202374nas a2200181 4500008004100000245009100041210006900132260001600201300001400217490000800231520178000239100002802019700002802047700002102075700002602096700001502122856005502137 2017 eng d00aBehavioural response evoked by conspecific distress calls in two neotropical treefrogs0 aBehavioural response evoked by conspecific distress calls in two cJan-12-2017 a942 - 9480 v1233 a

Anurans emit distress calls when attacked by predators as a defensive mechanism. As distress calls may trigger antipredator behaviour even in individuals that are not under attack, we tested whether this defensive behaviour induced behavioural changes in neighbouring conspecifics. We compared the behavioural responses of two species of Neotropical hylid frogs (genus Boana) to conspecific distress calls and white noise. Individuals of both species interrupted their vocal activity and decreased call rate after hearing the distress call. Natural variation on signal intensity calibrated among the nearest neighbours did not influence the response and we did not observe negative phonotaxis after any acoustic stimulus. Despite the fact that many predators are acoustically oriented, we could not determine if such response (reduced call rate) was induced by risk assessment or by the masking effect on advertisement calls. Boana faber responded similarly to white noise and distress calls, while B. bischoffi responded more intensely to distress calls. Duration of silence after playbacks in B. faber was longer than B. bischoffi. We suggest that, if the signals are interpreted as a risk cue by neighbouring conspecifics, each species may be preyed upon by different predators, as they may have led to distinct defensive strategies and different responses to distress calls. If risk assessment information is included in distress calls, it triggers behavioural responses only in the nearest neighbours, as we did not observe responses on the vocal activity of the interspecific chorus. Our results add relevant data about acoustic communication and interpretations by anurans, highlighting the importance of considering cues within common and widespread signals.

1 aForti, Lucas, Rodriguez1 aForti, Anna, Bárbara B1 aMárquez, Rafael1 aToledo, Luís, Felipe1 aFoster, S. uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-1202887nas a2200181 4500008004100000245007200041210006900113260001600182300001400198490000800212520232400220100002602544700002202570700001902592700002402611700001502635856005502650 2017 eng d00aDo birds differentiate between white noise and deterministic chaos?0 aDo birds differentiate between white noise and deterministic cha cJan-12-2017 a966 - 9730 v1233 a

Noisy, unpredictable sounds are often present in the vocalizations of fearful and stressed animals across many taxa. A variety of structural characteristics, called nonlinear acoustic phenomena, that include subharmonics, rapid frequency modulations, and deterministic chaos are responsible for the harsh sound quality of these vocalizations. Exposure to nonlinear sound can elicit increased arousal in birds and mammals. Past experiments have used white noise to test for effects of deterministic chaos on perceivers. However, deterministic chaos differs structurally from white noise (i.e., random signal with equal energy at all frequencies), and unlike white noise, may differ dramatically depending on how it is produced. In addition, the subtle structural variation of chaos may not be distinguishable in the environment due to the attenuation and degradation of sound over distance and different habitat types. We designed two experiments to clarify whether American robins (Turdus migratorius) and warbling vireos (Vireo gilvus) discriminate between white noise and deterministic chaos. We broadcast and re-recorded white noise and two exemplars of deterministic chaos—one generated with a Chua oscillator and the other generated using a logistic equation—at 1, 10, 20, 30, 40, and 80 m across open and forested habitat and used spectrogram correlations to compare stimuli along this degradational gradient. We found that sounds degraded similarly in both habitats when compared to a reference distance of 1 m. Comparing pairs of stimuli across distances suggested that Chua chaos was more easily distinguishable from noise and logistic chaos. In addition, all stimuli became more distinctive over increased distance. The second experiment tested behavioral responses of robins and warbling vireos to control sounds of tropical kingbird (Quiscalus mexicanus), white noise, and two exemplars of deterministic chaos (Chua and logistic). Neither American robins nor warbling vireos responded differently to at least two types of deterministic chaos and white noise, validating previous playback studies that used white noise as a surrogate for deterministic chaos. Uniform responses to a variety of nonlinear features in these birds possibly reflect error management in alarm signal detection.

1 aBlumstein, Daniel, T.1 aWhitaker, Jessica1 aKennen, Judith1 aBryant, Gregory, A.1 aKoenig, W. uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-1202441nas a2200217 4500008004100000245013500041210006900176260001600245520170700261653002801968653001801996653001502014653003002029653001102059653002502070100002402095700001802119700002602137700001702163856004302180 2017 eng d00aMale tree weta are attracted to cuticular scent cues but do not discriminate according to sex or among two closely related species0 aMale tree weta are attracted to cuticular scent cues but do not  cMay-08-20183 a

Recognition of conspecifics is an essential precursor of successful mating. Where related species coexist, species discrimination might be important, but because related species are similar, species signal recognition may actually be low. Chemical cues such as cuticular hydrocarbons (CHCs) are frequently used by insects to identify suitable sexual partners. We predicted that New Zealand tree weta ( Hemideina spp.), a genus of nocturnal ensiferan Orthoptera that live both allopatrically and sympatrically, use chemical signals from either frass or CHCs to find mates. In a series of six laboratory trials using both H. thoracica and H. crassidens , we found that male tree weta, but not female tree weta, occupied cavities primed with female cuticular cues more often than cavities without. However, males did not discriminate between chemical cues of male and female conspecifics, or between conspecifics and heterospecifics. In field trials, tree weta did not occupy artificial cavities primed with either female frass or female cuticular cues more often than unscented cavities. However, in both trials weta pref- erentially returned to cavities that had already been occupied earlier in the trials. A final field trial confirmed the presence of mixed species harems during the mating season in one region of sympatry. Our results suggest that selection on sex and spe- cies specific chemical cues that could be used to find conspecific mates is weak. Mixed species aggregations suggest that identification of conspecific mating cues has not evolved to be species specific. We infer that for male tree weta, the cost of mating with heterospecifics is likely less than not mating at all.

10acuticular hydrocarbons10ahybridization10aOrthoptera10areproductive interference10asignal10aspecies recognition1 aWehi, Priscilla, M.1 aMonks, Adrian1 aMorgan-Richards, Mary1 aTregenza, T. uhttp://doi.wiley.com/10.1111/eth.1265201984nas a2200217 4500008004100000245010900041210006900150260001600219300001400235490000800249520129800257653002701555653001501582653001501597653001801612100002201630700002201652700002301674700001501697856005401712 2017 eng d00aResponses of male cricket frogs ( Acris crepitans) to attenuated and degraded advertisement calls0 aResponses of male cricket frogs iAcris crepitansi to attenuated  cJan-05-2017 a357 - 3640 v1233 a

We examined the vocal and non-vocal responses of male cricket frogs (Acris crepitans) to conspecific advertisement calls that had been attenuated or degraded by reducing the depth of amplitude modulation (AM). Both are characteristic of changes to the call as it is transmitted through natural habitats. As stimulus calls became more intense or less degraded, male cricket frogs gradually decreased their call rate and increased the number of call groups and pulse groups in their calls, changes indicative of increased aggressive interactions. At the higher intensities and lower degradation levels, the probability that males would shift to one of two non-vocal behavioral responses, attacking the perceived intruder or ceasing calling and abandoning the call site, gradually increased. The results show that differences in signal attenuation and AM degradation levels are perceived by males and trigger both vocal and non-vocal behavioral responses consistent with their use in evaluating the distance to a challenging male. Furthermore, the results indicate that the male responses are graded, increasing as intensity rises and degradation falls, and hierarchical, with vocal responses preceding behavioral responses over the range of intensities and degradation levels presented.

10aacoustic communication10aaggression10aamphibians10acricket frogs1 aVenator, Kurt, R.1 aRyan, Michael, J.1 aWilczynski, Walter1 aKoenig, W. uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-502860nas a2200301 4500008004100000245018600041210006900227260001600296300001400312490000800326520181600334653002202150653002702172653002202199653003502221653001402256653001902270100002202289700002602311700001702337700002602354700002702380700002002407700002502427700002802452700002402480856005402504 2017 eng d00aIndividuality of distress and discomfort calls in neonates with bass voices: Wild-living goitred gazelles ( Gazella subgutturosa) and saiga antelopes ( Saiga tatarica)0 aIndividuality of distress and discomfort calls in neonates with  cJan-05-2017 a386 - 3960 v1233 a

Neonate ruminants produce distress calls when captured by a predator and discomfort milk begging calls when hungry. In many neonate ruminants, the distress and discomfort calls are high-frequency vocalizations, in which the fundamental frequency is the key variable for recognition of their emotional arousal by caregivers. In contrast, in this study, we examine the low-frequency open-mouth distress and discomfort calls in the neonates of two species of wild-living ungulates, which clearly highlight vocal tract resonances (formants). In the goitred gazelle (Gazella subgutturosa), the distress calls were higher in fundamental frequency (f0) and in the first and third formants than the discomfort calls. The accuracy of classifying individuals by variables of distress calls with discriminant function analysis (67%) was significantly lower than that of discomfort calls (85%). In the saiga (Saiga tatarica), only the third formant was higher in the distress calls than in the discomfort calls. The accuracy of classifying individuals by variables of distress calls (89%) did not differ significantly from that of discomfort calls (94%). Thus, the use of acoustic cues to vocal identity and to the degree of arousal differs between the two species. Calls were significantly more individualistic in the saiga, probably because this species lives in large herds and neonates use a ‘following’ antipredatory strategy, in which vocal individuality is crucial for mother–offspring communication. In contrast, goitred gazelles live in smaller groups and neonates use a ‘hiding’ antipredatory strategy. Accordingly, mothers can rely on additional environmental cues for spotting their young and this may decrease the necessity for individualization of the calls of neonates.

10aacoustic behavior10aantipredatory strategy10aemotional arousal10amother-offspring communication10aruminants10avocal identity1 aVolodin, Ilya, A.1 aSibiryakova, Olga, V.1 aFrey, Roland1 aEfremova, Kseniya, O.1 aSoldatova, Natalia, V.1 aZuther, Steffen1 aKisebaev, Talgat, B.1 aSalemgareev, Albert, R.1 aVolodina, Elena, V. uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-502184nas a2200193 4500008004100000245007800041210006900119260001600188300001400204490000800218520156700226653001101793653003201804653002501836100002701861700002401888700002401912856005401936 2017 eng d00aSubharmonics increase the auditory impact of female koala rejection calls0 aSubharmonics increase the auditory impact of female koala reject cJan-08-2017 a571 - 5790 v1233 a

Although non-linear phenomena are common in human and non-human animal vocalisations, their functional relevance remains poorly understood. One theory posits that non-linear phenomena generate unpredictability in vocalisations, which increases the auditory impact of vocal signals, and makes animals less likely to habituate to call repetition. Female koalas (Phascolarctos cinereus) produce vocal signals when they reject male copulation attempts that contain relatively high levels of non-linear phenomena, and thus may function as attention grabbing vocal signals during the breeding season. To test this hypothesis, we used playback experiments: firstly, to determine whether female rejection calls induce heightened behavioural responses in free-ranging male koalas during the breeding season, and secondly, to examine how the relative amount of non-linear phenomena in rejection calls influences male behavioural response. The results show that male koalas look for longer towards speakers broadcasting playback sequences of male bellows followed by a series of female rejection calls than those broadcasting only male bellows. In addition, female rejection call sequences with more subharmonics, higher harmonics-to-noise ratios, and less biphonation produced the greatest male looking responses. Our findings support the hypothesis that female koala rejection calls function to grab male attention during the breeding season, and indicate that subharmonics are the main acoustic feature that increases the auditory impact of these vocal signals.

10akoalas10amammal vocal communication10anon-linear phenomena1 aCharlton, Benjamin, D.1 aWatchorn, Darcy, J.1 aWhisson, Desley, A. uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-802963nas a2200193 4500008004100000245012100041210006900162260001600231300001400247490000800261520233300269100001802602700001902620700001802639700001502657700001702672700002602689856005402715 2017 eng d00aAlarm call-based discrimination between common cuckoo and Eurasian sparrowhawk in a Chinese population of great tits0 aAlarm callbased discrimination between common cuckoo and Eurasia cJan-08-2017 a542 - 5500 v1233 a

Morphological resemblance of the common cuckoo Cuculus canorus to the Eurasian sparrowhawk Accipiter nisus has been regarded as an example of predator mimicry. Common hosts could distinguish parasites as the result of coevolution, while rare hosts or non-hosts may mistake cuckoos for hawks because rare hosts or non-hosts behave similarly when faced with these two species. Birds usually produce alarm calls in addition to showing behavioral responses when in danger. However, previous studies of identification by rare hosts or non-hosts of sparrowhawks usually lacked experimental evidence of alarm calls. Great tits Parus major, a rare cuckoo host, perform similar behaviors and usually produce alarm calls in response to sparrowhawks and common cuckoos. Here, we tested whether great tits could distinguish common cuckoo from sparrowhawk based on analysis of their alarm calls and the effects of playback of alarm calls on conspecific behavior. Previous studies showed that great tits have a complex communication system that conveys information about predators, and they could perform different kinds of response behavior to different alarm calls. If great tits have not made the ability to distinguish between common cuckoo and sparrowhawk, then their acoustic responses to these two species and their response behaviors in playback experiments should be similar. Specimens of a common cuckoo (parasite), a sparrowhawk (predator) and an Oriental turtle dove Streptopelia orientalis (harmless control) were used to elicit and subsequently record the response behavior and alarm calls of great tits. There was no significant difference in behavioral response among great tits when exposed to the dummy of cuckoo, sparrowhawk and dove. In contrast, they differed significantly in alarm calls. Great tits produced more notes per call that contained increasing D-type and decreasing I-type notes when responding to sparrowhawk as compared to cuckoo or dove. In playback experiments, we found that great tits responded more strongly to great tit hawk than to great tit cuckoo or great tit dove alarm calls. Our study suggests that great tits are able to distinguish sparrowhawks from common cuckoos and convey relevant information in alarm calls by adjusting the number and combinations of notes of a single call type.

1 aYu, Jiangping1 aXing, Xiaoying1 aJiang, Yunlei1 aLiang, Wei1 aWang, Haitao1 aMøller, Anders, Pape uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-801999nas a2200265 4500008004100000245014600041210006900187260001600256300001400272490000800286520117800294653001001472653002601482653002201508653002401530653001401554100001501568700001601583700001901599700001301618700001601631700001601647700001601663856005401679 2017 eng d00aThe effects of cultural drift on geographic variation in echolocation calls of the Chinese rufous horseshoe bat ( Rhinolophus sinicus)0 aeffects of cultural drift on geographic variation in echolocatio cJan-08-2017 a532 - 5410 v1233 a

Drift, selection, or their combined effects commonly drive geographic variation in traits. Clarifying the relative roles of each process is a long-standing research goal in evolutionary biology. Acoustic signals of bats are a phenotypic characteristic that plays an important role in social organization and species recognition. We extensively sampled the Chinese rufous horseshoe bat (Rhinolophus sinicus) throughout China and Vietnam and reconstructed a species phylogeny to better understand the patterns and causes of the geographic variation of acoustic signals. Our results showed that the resting frequency (RF) of calls varied with latitude, sex, and distance among different colony locations. RF differences were not correlated with genetic distance (based on only one nuclear locus and the mitochondrial locus), climatic factors (mean annual temperature and mean annual precipitable water), or body size, although differences in calls increased with distance among various populations. This suggests that cultural drift may play more important roles than genetic drift and acoustic adaptation in shaping acoustic differences within regions in R. sinicus.

10adrift10ageographic variation10aresting frequency10aRhinolophus sinicus10aselection1 aXie, Lifen1 aSun, Keping1 aJiang, Tinglei1 aLiu, Sen1 aLu, Guanjun1 aJin, Longru1 aFeng, Jiang uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-802451nas a2200169 4500008004100000245011300041210006900154260001600223300001400239490000800253520189100261100002502152700002402177700002202201700001502223856004302238 2017 eng d00aSexual differentiation and seasonal variation in response to conspecific and heterospecific acoustic signals0 aSexual differentiation and seasonal variation in response to con cJan-06-2017 a460 - 4660 v1233 a

Interspecific territoriality is frequently reported between closely related species; however, few studies have demonstrated interspecific territoriality between distantly related species living in sympatry. We conducted playback experiments to investigate territorial behaviour in male and female White-bellied Wrens (Uropsila leucogastra) in response to simulated conspecific and heterospecific intruders during the breeding and non-breeding seasons. We explored whether heterospecific songs of the Happy Wren (Pheugopedius felix), a distantly related species and ecological competitor, elicited antagonistic responses from focal White-bellied Wrens, and whether such responses differed between the sexes. We also examined whether male and female responses to conspecific and heterospecific rivals varied with season. We found that male White-bellied Wrens always responded to conspecific song, and responded significantly more to heterospecific song compared to a control stimulus (Tropical Parula, Setophaga pitiayumi). In contrast, although female White-bellied Wrens responded strongly to conspecific song, their response to heterospecific song did not differ significantly from the control stimulus. The proportion of males that responded to heterospecific songs and the proportion of females that responded to conspecific songs varied seasonally, showing significantly lower responses during the breeding season. The intense responses of male White-bellied Wrens to playback of heterospecific songs suggest that they recognise ecological competitors based on their vocal signals. Furthermore, the decrease in agonistic interactions during the breeding season is in line with the hypothesis that aggressive behaviour may be detrimental to reproductive and parental activity, and the hypothesis that heterospecific animals pose less of a threat during the breeding season.

1 aSosa-López, Roberto1 aMennill, Daniel, J.1 aRenton, Katherine1 aKoenig, W. uhttp://doi.wiley.com/10.1111/eth.1261602246nas a2200349 4500008004100000245010300041210006900144260001600213300001400229490000800243520124400251653001401495653001401509653001201523653001801535653001601553653002101569653001601590653001401606100002401620700002201644700002601666700002201692700002201714700002001736700002301756700001801779700001901797700002201816700001501838856004301853 2017 eng d00aNo need to shout: Effect of signal loudness on sibling communication in barn owls Tyto alba0 aNo need to shout Effect of signal loudness on sibling communicat cJan-06-2017 a419 - 4240 v1233 a

In animal communication, signal loudness is often ignored and seldom measured. We used a playback experiment to examine the role of vocal loudness (i.e., sound pressure level) in sibling to sibling communication of nestling barn owls Tyto alba. In this species, siblings vocally negotiate among each other for priority access to parental food resources. Call rate and call duration play key roles in this vocal communication system, with the most vocal nestlings deterring their siblings from competing for access to the food item next delivered by parents. Here, we broadcast calls at different loudness levels and call rate to live nestlings. The loudness of playback calls did not affect owlets' investment in call rate, call duration or call loudness. The rate at which playback calls were broadcast affected owlets' call rate but did not influence their response in terms of loudness. This suggests that selection for producing loud signals may be weak in this species, as loud calls may attract predators. Moreover, given that owlets do not overlap their calls and that they communicate to nearby siblings in the silence of the night, loud signals may not be necessary to convey reliable information about food need.

10aacoustics10aamplitude10abegging10acommunication10acompetition10amultiple signals10anegotiation10aplaybacks1 aDreiss, Amélie, N.1 aDucouret, Pauline1 aRuppli, Charlène, A.1 aRossier, Virginie1 aHernandez, Lucile1 aFalourd, Xavier1 aMarmaroli, Patrick1 aCazau, Dorian1 aLissek, Hervé1 aRoulin, Alexandre1 aFusani, L. uhttp://doi.wiley.com/10.1111/eth.1261202606nas a2200205 4500008004100000245010200041210006900143260001600212520194500228653001802173653002602191653001202217653002902229653002402258100001702282700002302299700002002322700001502342856004302357 2017 eng d00aRestricted responsiveness to noise interference in two anurans from the southern temperate forest0 aRestricted responsiveness to noise interference in two anurans f cFeb-08-20183 a

Animals adopt different strategies to communicate by means of sound in noisy envi - ronments such that some species increase, while others decrease their vocal activity in the presence of interference. Anuran amphibians from diverse latitudes exhibit both kinds of responses. Recent studies have shown that males of Batrachyla taeniata and Batrachyla antartandica from the temperate austral forest do not call in response to the presentation of advertisement calls of sympatric congeneric species. In contrast, Batrachyla leptopus responds to these signals in a similar way as to conspecific calls. The responsiveness of B. taeniata to natural abiotic interference has also been tested and found that noises of such sources produce strong increases in vocal activity. To assess the diversity in responsiveness to acoustic intrusion in this group, we exposed males of B. leptopus and B. antartandica to prolonged pre- recorded natural abiotic noises of wind, creek, rain, and to a band- pass noise centered at 2,000 Hz, at 67 dB Sound Pressure Level (SPL). The subjects did not increase their vocal activity signifi - cantly when exposed to these sounds and to band- pass noise at increasing intensities (55–79 dB SPL). These results contrast with the increase in vocal activity observed previously in B. taeniata to continuous abiotic noise and point to the existence of di - verse strategies to confront acoustic intrusion among related species. The lack of vocal activation observed also contrasts with the responsiveness of B. leptopus to het- erospecific signals, but parallels the lack of response to such sounds in B. antartandica . Furthermore, the results obtained contrast with the responsiveness of these species to synthetic prolonged sounds observed in previous studies, suggesting that the modes of responses to acoustic intrusion may depend on previous experience, rather than having a species- specific nature.

10aabiotic noise10aacoustic interference10aanurans10aaustral temperate forest10asound communication1 aPenna, Mario1 aCisternas, Javiera1 aToloza, Jessica1 aFoster, S. uhttp://doi.wiley.com/10.1111/eth.1264402575nas a2200133 4500008004100000245009000041210006900131260001600200300001400216490000700230520211800237100001702355856006902372 1987 eng d00aA Comparative Study of Mating Behaviour in Some Neotropical Grasshoppers (Acridoidea)0 aComparative Study of Mating Behaviour in Some Neotropical Grassh cDec-01-1987 a265 - 2960 v763 a

Aspects of premating and mating behaviour in several South American grasshopppers (Acridoidea) are described and compared. Examples of communication by acoustical, visual and chemical means are given.

Acoustic signals are emitted only by species of the subfamilies Gomphocerinae, Acridinae, Romaleinae and Copiocerinae. Each subfamily has distinct sound-producing mechanisms, and the songs occur in different behavioural contexts. In Gomphocerinae and Acridinae the sexes recognize and attract each other by species-specific songs produced by a femuro-tegminal stridulatory mechanism. In contrast, Romaleinae produce a simple song by rubbing the hindwings against the forewings. These songs are similar in different species and no attraction of females could be demonstrated, but the behaviour may function in male-male interaction and during copulation. Sexual pheromones also play a role in this subfamily. Acoustic activity during copulation has been observed in Aleuasini (Copiocerinae), but its function is still unclear.

No sound production at all exists in the Leptysminae, Rhytidochrotinae, Ommatolampinae, Melanoplinae, Proctolabinae and Bactrophorinae, but conspicuous movements of hindlegs (kneewaving) and antennae were observed. In some species these form part of a soundless courtship display.

Ecological constraints have little influence on the basic mating strategies: romaleine, gomphocerine and melanopline grasshoppers often coexist in various habitats, but show the divergent behaviour patterns characteristic of their respective subfamilies. Intrinsic factors of female reproductive physiology seem to be more important: a hormonally controlled reproductive cycle in gomphocerine females provides for only few short copulations, while romaleine females copulate frequently and longer. In Gomphocerinae and Acridinae, receptive females are rare (male-biased operational sex ratio) which leads to intense competition among males. It is hypothesized that this could be responsible for the high diversification of song and courtship patterns in these subfamilies.

1 aRiede, Klaus uhttp://blackwell-synergy.com/doi/abs/10.1111/eth.1987.76.issue-401489nas a2200145 4500008004100000245012200041210006900163260001600232300001200248490000700260520096100267100002401228700002201252856006901274 1986 eng d00aConfusion of Phonotaxis by Masking Sounds in the Bushcricket Conocephalus brevipennis (Tettigoniidae: Conocephalinae)0 aConfusion of Phonotaxis by Masking Sounds in the Bushcricket Con cDec-01-1986 a19 - 280 v733 a

Female Conocephalus brevipennis, executing phonotaxis to the call of a conspecific male broadcast from a speaker, were subjected to varying levels of background sound so as to progressively mask the attracting signal. The background consisted of either random noise or the call of a sympatric congener, C. nigropleurum and was delivered from above the orienting female. Disruption of phonotaxis was assayed by monitoring the angular dispersion of the female's exit path from the arena, relative to the position of the conspecific call. Random noise significantly interfered with phonotaxis when it was within 2 dB of the conspecific call intensity, both signals measured at the centre of the arena. The equivalent effect of the call C. nigropleurum was 5 dB above conspecific call intensity. The implication of signal loss within background noise is discussed as are the possible interactive behaviours of competing sympatric syntopic species.

1 aBailey, Winston, J.1 aMorris, Glenn, K. uhttp://blackwell-synergy.com/doi/abs/10.1111/eth.1986.73.issue-100625nas a2200145 4500008004100000022001400041245012500055210006900180260001600249300001600265490000800281100002600289700002000315856014400335 2001 eng d a0179-161300aDivergence between the Courtship Songs of the Field Crickets Gryllus texensis and Gryllus rubens (Orthoptera, Gryllidae)0 aDivergence between the Courtship Songs of the Field Crickets Gry cMay-12-2003 a1075 - 10850 v1071 aFitzpatrick, Mark, J.1 aGray, David, A. uhttp://doi.wiley.com/10.1046/j.1439-0310.2001.00730.xhttps://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1439-0310.2001.00730.x