02213nas a2200241 4500008004100000245010200041210006900143300001200212490000700224520146900231653001101700653000901711653001701720653002101737653002501758653002601783653002501809653002601834653002101860100002701881700002201908856004101930 1997 eng d00aA New Examination of Echolocation Calls of Some Neotropical Bats (Emballonuridae and Mormoopidae)0 aNew Examination of Echolocation Calls of Some Neotropical Bats E a954-9630 v873 a

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.

10aAnabat10abats10aecholocation10aPteronotus davyi10aPteronotus parnellii10aPteronotus personatus10aRhynchonycteris naso10aSaccopteryx bilineata10avocal signatures1 aO'Farrell, Michael, J.1 aMiller, Bruce, W. uhttps://bio.acousti.ca/nn/node/5805302408nas a2200373 4500008004100000245007800041210006900119300001200188490000700200520132500207653002801532653001101560653000901571653002501580653001501605653002501620653001901645653002401664653001401688653001601702653002601718653001901744653001501763653002301778653002101801653002501822653002601847653002101873653002601894653002401920100002701944700002201971856004101993 1999 eng d00aUse of vocal signatures for the inventory of free-flying Neotropical bats0 aUse of vocal signatures for the inventory of freeflying Neotropi a507-5160 v313 a

An ongoing study is being conducted to test the efficacy of the Anabat II detector and analysis system in obtaining reliable vocal signatures for the identification of non-phyllostomid species of bats. We sampled a wide range of elevations and associated habitat types throughout Belize. Anabat provides an instantaneous output of echolocation call structure with a laptop computer. Select sequences can be saved directly to the hard drive, avoiding extraneous noise and sound distortion commonly associated with tape recorders. To date, 18 of the 37 species known or expected
to occur in the study region were identified by recognizable differences in the time-frequency characteristics of echolocation calls. In general, each family is recognizable by call structure patterns and species readily separated by frequency range parameters. Species that commute or forage at high altitudes are not susceptible to capture but are conspicuous by acoustic sampling. Further work is needed to determine limitations of the equipment, establish better sampling procedures, and develop a comprehensive library of vocal signatures incorporating the range of variation
inherent in each species. As this work progresses, we predict the addition of hitherto unknown species occurring within the study region.

10aacoustic identification10aAnabat10abats10aBauerus dubiaquercus10aChiroptera10adiversity assessment10aEmballonuridae10aEptesicus furinalis10ainventory10aMormoopidae10aMormoops megalophylla10aMyotis elegans10aNeotropics10aNoctilio leporinus10aPteronotus davyi10aPteronotus parnellii10aPteronotus personatus10aRhogeessa tumida10aSaccopteryx bilineata10aSaccopteryx leptura1 aO'Farrell, Michael, J.1 aMiller, Bruce, W. uhttps://bio.acousti.ca/nn/node/5805202640nas a2200385 4500008004100000245007700041210006900118300001000187490000700197520153100204653001101735653000901746653001501755653001701770653002401787653001901811653003001830653002201860653001701882653001801899653002201917653002201939653002401961653002301985653002202008653002302030653002602053653002602079653001402105653002102119100002702140700002202167700002402189856004102213 1999 eng d00aQualitative Identification of Free-flying Bats Using the Anabat Detector0 aQualitative Identification of Freeflying Bats Using the Anabat D a11-230 v803 a

A variety of ultrasonic bat detectors have been used over the past 3 decades to identify freeflying bats. Analyses of recorded echolocation calls were slow and typically restricted to few calls and at a resolution obscuring details of call structure. The Anabat II detector and associated zerocrossings analysis system allows an immediate examination, via a laptop computer, of the timefrequency structure of calls as they are detected. These calls can be stored on the hard drive for later examination, editing, and measurement. Many North American bats can be identified to species by qualitatively using certain structural characteristics of calls, primarily approximate maximum and minimum frequencies and morphological aspects of calls e.g., linearity and changes in slope). To identify calls precisely, it is important to use a continuous sequence of calls from an individual in normal flight rather than from single isolated calls. All calls are not equally useful, and many fragmentary calls must be discarded before making a determination. Each sequence of calls must be examined to ensure that multiple bats have not been simultaneously recorded, which confounds correct identification. We found the percentage of nonusable calls within usable vocal sequences to be highest in vespertilionids 20-40%), whereas for other families this was frequently <10%. Active rather than passive collection of data maximizes quality and quantity of diagnostic calls and provides a contextual base for the investigator.

10aAnabat10abats10aChiroptera10aecholocation10aEptesicus furinalis10aidentification10aLasionycteris noctivagans10aLasiurus cinereus10aLasiurus ega10aMolossus ater10aMolossus molossus10aMolossus sinaloae10aMyotis californicus10aMyotis ciliolabrum10aMyotis yumanensis10aNoctilio leporinus10aSaccopteryx bilineata10aTadarida brasiliensis10atechnique10avocal signatures1 aO'Farrell, Michael, J.1 aMiller, Bruce, W.1 aGannon, William, L. uhttps://bio.acousti.ca/nn/node/5805102632nas a2200289 4500008004100000245011000041210006900151520174700220653001501967653002501982653002502007653000902032653001702041653002502058653001002083653001802093653001702111653002102128653002402149653001902173100001502192700001402207700001802221700001402239700002202253856006702275 2019 eng d00aAutomatic standardized processing and identification of tropical bat calls using deep learning approaches0 aAutomatic standardized processing and identification of tropical3 a

Consistent and comparable metrics to automatically monitor biodiversity across the landscape remain a gold-standard for biodiversity research, yet such approaches have frequently been limited to a very small selection of species for which visual approaches (e.g., camera traps) make continuous monitoring possible. Acoustic-based methods have been widely applied in the monitoring of bats and some other taxa across extended spatial scales, but are have yet to be applied to diverse tropical communities.

In this study, we developed a software program “Waveman” and prepared a reference library using over 880 audio-files from 36 Asian bat species. The software incorporated a novel network “BatNet” and a re-checking strategy (ReChk) to maximize accuracy. In Waveman, BatNet outperforms three other published networks: CNNFULL, VggNet and ResNet_v2, with over 90% overall accuracy and 0.94 AUC on the ROC plot. The classification accuracy rates for all 36 species are at least 86% when analysed in combination. Moreover, our library preparation and ReChk greatly improved the sensitivity and reduced the false positive rate, when tested with 15 species for which more detailed and situationally diverse records were available. Finally, BatNet was successfully used to identify Hipposideros larvatus and Rhinolophus siamensis from three different environments. We hope this pipeline is useful tool to process bioacoustic data accurately, effectively and automatically, therefore allowing for greater standardization and comparability for researchers to understand bat activities across space and time and therefore provide a consistent tool for monitoring biodiversity for management and conservation.

10aAlgorithms10aAutomated monitoring10aAutomatic processing10abats10abioacoustics10aBiodiversity metrics10aCalls10aDeep learning10aecholocation10amachine learning10aMonitoring protocol10aNeural network1 aChen, Xing1 aZhao, Jun1 aChen, Yan-hua1 aZhou, Wei1 aHughes, Alice, C. uhttps://linkinghub.elsevier.com/retrieve/pii/S000632071930896102337nas a2200217 4500008004100000245008600041210006900127520164500196653002401841653000901865653002201874653002701896653002001923653001801943100001701961700001601978700002101994700002102015700002102036856006202057 2019 eng d00aDoes bat response to traffic noise support the misleading cue hypothesis?Abstract0 aDoes bat response to traffic noise support the misleading cue hy3 a

The world has become a noisier place due to the increase in urbanization. Noise is generally considered an impediment, altering an animal’s behavior through masking or distraction. But noise can also provide useful information about the environment. For animals that rely on natural environmental noise as an indicator of favorable foraging conditions, increasing levels of anthropogenic noise might mislead informed decision-making. Bats use rain noise, a natural environmental cue, to delay their emergence from the roost, presumably to avoid sensory and metabolic costs associated with foraging in heavy rain. Here we tested the “misleading cue hypothesis,” asking whether traffic noise is mistaken for rain noise by bats. Given the acoustic similarity between rain noise and traffic noise, we predicted that bats would confuse the two. We conducted a playback experiment using rain, traffic, and ambient noise at natural roosts of common big-eared bats (Micronycteris microtis, Phyllostomidae) and recorded bat emergence behavior. In contrast to their response to rain noise, the bats did not delay roost emergence in response to traffic noise. Thus, we found that bats were able to discriminate between traffic noise and rain noise and were not misled by similarity in acoustic parameters in the two noise types, when emerging from their roost. Emerging bats did show more exploration flights during traffic noise than during rain noise, but not during ambient noise, suggesting that they perceive traffic noise as a novel acoustic cue. Our data provide new insights into perception of traffic noise by bats.

10aanthropogenic noise10abats10aevolutionary trap10aMicronycteris microtis10amisleading cues10aTraffic noise1 aGeipel, Inga1 aAmin, Bawan1 aPage, Rachel, A.1 aHalfwerk, Wouter1 aCandolin, Ulrika uhttps://academic.oup.com/beheco/article/30/6/1775/557481101564nas a2200193 4500008004100000245005200041210005200093520101400145653001901159653000901178653001701187653002301204653002301227653001301250100001401263700001301277700001401290856006601304 2019 eng d00aSensory gaze stabilization in echolocating bats0 aSensory gaze stabilization in echolocating bats3 a

Sensing from a moving platform is challenging for both man-made machines and animals. Animals' heads jitter during movement, so if the sensors they carry are not stabilized, any spatial estimation might be biased. Flying animals, like bats, seriously suffer from this problem because flapping flight induces rapid changes in acceleration which moves the body up and down. For echolocating bats, the problem is crucial. Because they emit a sound to sense the world, an unstable head means sound energy pointed in the wrong direction. It is unknown how bats mitigate this problem. By tracking the head and body of flying fruit bats, we show that they stabilize their heads, accurately maintaining a fixed acoustic-gaze relative to a target. Bats can solve the stabilization task even in complete darkness using only echo-based information. Moreover, the bats point their echolocation beam below the target and not towards it, a strategy that should result in better estimations of target elevation.

10aactive sensing10abats10aecholocation10agaze stabilization10asensory perception10atracking1 aEitan, O.1 aKosa, G.1 aYovel, Y. uhttps://royalsocietypublishing.org/doi/10.1098/rspb.2019.149601703nas a2200241 4500008004100000245008100041210006900122520100600191653000901197653002301206653002501229653002001254653002201274100001801296700001501314700001401329700001101343700001801354700001601372700001601388700001601404856004101420 2019 eng d00aVocal Development of Horsfield's Leaf-Nosed Bat Pups (Hipposideros larvatus)0 aVocal Development of Horsfields LeafNosed Bat Pups Hipposideros 3 a

Bats are an appealing animal for investigating the biological basis and evolution of speech-related traits in wild mammal systems. We investigated vocal development in Horsfield's leaf-nosed bat pups, Hipposideros larvatus. We found that newborn bats emit many types of isolation calls, including downward frequency modulation (DFM), arched frequency modulation (AFM), upward frequency modulation (UFM), and others. The gradual decrease of Euclidean distance measurements revealed that pup isolation calls (DFM, AFM, UFM) gradually change into adult social calls. Furthermore, one of the isolation call types (UFM type) encoded an individual signature. By contrast, we report that early echolocation calls and isolation calls develop in parallel. As pups develop, early echolocation calls gradually mature and transform into adult-like echolocation calls. The interval and duration of echolocation calls decreases, while the peak frequency and bandwidth of frequency modulation increases.

10abats10aecholocation calls10aindividual signature10aisolation calls10avocal development1 aChi, Tingting1 aLIU, Muxun1 aTan, Xiao1 aLi, Yu1 aXiao, Yanhong1 aSun, Keping1 aJin, Longru1 aFeng, Jiang uhttps://bio.acousti.ca/nn/node/5757602274nas a2200241 4500008004100000022001400041245009400055210006900149260001600218300001500234520143200249653000901681653002001690653001301710653002101723653001001744653000901754100001701763700002401780700002101804700002101825856018601846 2019 eng d a0022-094900aNoise as an informational cue for decision-making: the sound of rain delays bat emergence0 aNoise as an informational cue for decisionmaking the sound of ra cSep-01-2020 ajeb.1920053 a

Background noise can have strong negative consequences on animals, reducing individual fitness by masking communication signals, impeding prey detection and increasing predation risk. While the negative impacts of noise across taxa have been well documented, the use of noise as an informational cue, providing animals with reliable information on environmental conditions has been less well studied. In the tropical rainforest, downpours can be intense and frequent. Strong rainfall may impede efficient orientation and foraging for bats that need echolocation to both navigate and detect prey, and can result in higher flight costs due to increased metabolic rates. Using playback experiments at natural roosts we tested whether two bat species, differing in their hunting strategies and foraging habitats, use rain noise as a cue to delay emergence from their roosts. We found that both species significantly delayed their emergence time during rain noise playbacks compared to silence and ambient noise controls. We conclude that bats can use background noise, here the acoustic component of rainfall, as a reliable informational cue to make informed decisions, here about whether to initiate foraging trips or remain in the shelter of their roosts. Our findings suggest that environmental background noise can sometimes be beneficial to animals, in particular in situations where other sensory cues may be absent.

10abats10adecision-making10aforaging10ainformation cues10aNoise10arain1 aGeipel, Inga1 aSmeekes, Marcus, J.1 aHalfwerk, Wouter1 aPage, Rachel, A. uhttp://jeb.biologists.org/lookup/doi/10.1242/jeb.192005https://syndication.highwire.org/content/doi/10.1242/jeb.192005https://syndication.highwire.org/content/doi/10.1242/jeb.19200502507nas a2200253 4500008004100000022001400041245012300055210006900178260001600247520173100263653002701994653000902021653001002030653001702040653002102057100001902078700001502097700001602112700001202128700001702140700001602157700002402173856005602197 2019 eng d a1435-944800aBats increase vocal amplitude and decrease vocal complexity to mitigate noise interference during social communication0 aBats increase vocal amplitude and decrease vocal complexity to m cOct-01-20193 a

Natural background noises are common in the acoustic environments in which most organisms have evolved. Therefore, the vocalization and sound perception systems of vocal animals are inherently equipped to overcome natural background noise. Human-generated noises, however, pose new challenges that can hamper audiovocal communication. The mechanisms animals use to cope with anthropogenic noise disturbances have been extensively explored in a variety of taxa. Bats emit echolocation pulses primarily to orient, locate and navigate, while social calls are used to communicate with conspecifics. Previous studies have shown that bats alter echolocation pulse parameters in response to background noise interference. In contrast to high-frequency echolocation pulses, relatively low-frequency components within bat social calls overlap broadly with ambient noise frequencies. However, how bats structure their social calls in the presence of anthropogenic noise is not known. Here, we hypothesized that bats leverage vocal plasticity to facilitate vocal exchanges within a noisy environment. To test this hypothesis, we subjected the Asian particolored bat, Vespertilio sinensis, to prerecorded traffic noise. We observed a significant decrease in vocal complexity (i.e., an increased frequency of monosyllabic calls) in response to traffic noise. However, an increase in the duration and frequency of social calls, as have been observed in other species, was not evident. This suggests that signal simplification may increase communication efficacy in noisy environments. Moreover, V. sinensis also increased call amplitude in response to increased traffic noise, consistent with the predictions of the Lombard effect.

10aacoustic communication10abats10aNoise10aSocial calls10avocal plasticity1 aJiang, Tinglei1 aGuo, Xiong1 aLin, Aiqing1 aWu, Hui1 aSun, Congnan1 aFeng, Jiang1 aKanwal, Jagmeet, S. uhttp://link.springer.com/10.1007/s10071-018-01235-002261nas a2200229 4500008004100000245009200041210006900133260001600202520158200218653000901800653001301809653001701822653003001839100001601869700001201885700002001897700001501917700002001932700001401952700001601966856004901982 2018 eng d00aSocial vocalizations of big-footed myotis (Myotis macrodactylus) during foraging0 aSocial vocalizations of bigfooted myotis iMyotis macrodactylusi  cFeb-12-20203 a

Acoustic signals play a crucial role in transmitting information and maintaining social stability in gregarious animals, especially in echolocating bats which rely primarily on biological sonar for navigating in the dark. In the context of foraging without relying on tactile, visual, or olfactory cues, acoustic signals convey information not only on food, but also on ownership and defense of resources. However, studies on such information remain fragmentary. In the present study, we aim to document the social vocal repertoire of Myotis macrodactylus at natural foraging sites. Multiple acoustic analyses and spectrographic classification revealed a rich foraging vocal repertoire comprising 6 simple syllables and 2 composites. Discriminant function analyses associated with a subset‐validation procedure provided an optimal method to spectrographically classify all recorded sounds into different syllable types. Multidimensional scaling of median values of multiple parameters further confirmed notable differences among these syllables in a three‐dimensional space. In addition, Euclidean distance analysis showed that there were some spectral similarities between specific social vocal syllables and feeding buzzes, which implied a potential jamming role. Altogether, the data indicate that bats at foraging sites under natural conditions used variant social vocalizations with different functions in addition to echolocation calls, providing supporting evidence for further work on the function and vocal mechanisms of acoustic communication in mammals.

10abats10aforaging10aSocial calls10aSpectro-temporal features1 aGuo, Dongge1 aLuo, Bo1 aZhang, Kangkang1 aLIU, Muxun1 aMetzner, Walter1 aLiu, Ying1 aFeng, Jiang uhttp://doi.wiley.com/10.1111/1749-4877.1236703163nas a2200277 4500008004100000022001300041245009800054210006900152260001600221300001400237490000800251520229700259653002702556653000902583653001402592653001602606653001802622653001702640653004202657653003802699653001802737653002102755100001802776700002502794856006602819 2017 eng d a0003347200aTo seek or speak? Dual function of an acoustic signal limits its versatility in communication0 aTo seek or speak Dual function of an acoustic signal limits its  cJan-05-2017 a135 - 1520 v1273 a

The perception of different attributes of conspecifics is an integral part of intraspecific communication. It can facilitate the recognition of interaction partners or the assessment of potential mates. Acoustic signals can encode fine-scaled information through the interplay of acoustic variability and specificity. A reliable vocal signature is both unique within a class and variable between classes. Therefore, acoustic complexity might be associated with the number of classes to be discriminated. We investigated the assumption that limitations to signal design may affect the communicative functionality of a signal. To do so, we chose a signal with potentially dual functionality which may therefore display such limitations. In bats, echolocation is used primarily for foraging and orientation but there is increasing support for its additional role in communication. An acoustic analysis of echolocation pulses of the bat Rhinolophus clivosus confirmed sex and individual vocal signatures in echolocation pulses. A habituation–dishabituation playback experiment suggested that bats perceived these signatures because listening bats clearly discriminated between the sexes (two classes) and between individuals (representatives of a multiclass category), although to different degrees. The simple acoustic structure of these vocalizations provides sufficient specificity for sex discrimination but has limitations for individual discrimination because pulse parameters of individuals increasingly overlapped with increasing group size. We conclude that selection for the primary function of echolocation restricts the acoustic space available for communication. However, we frequently observed echolocation pulses with conspicuous structural modifications. Statistical analyses revealed that these vocalizations yielded increased individual distinctiveness. Such added systematic variation may indicate a communicative function and perhaps a signalling intent of the emitter, although the latter has yet to be tested. The findings suggest that the required specificity for effective communication could be obtained through modification of echolocation variants when adaptations for orientation and foraging constrain the evolution of complex communication signatures.

10aacoustic communication10abats10aco-option10aconstraints10aeavesdropping10aecholocation10ahabituation–dishabituation playback10aindividual and sex discrimination10asignal design10avocal signatures1 aBastian, Anna1 aJacobs, David, Steve uhttp://linkinghub.elsevier.com/retrieve/pii/S000334721730077502313nas a2200277 4500008004100000022001300041245008800054210006900142260001600211300001400227490000800241520150900249653002701758653000901785653003701794653001301831653001601844100001201860700001601872700001601888700001601904700001901920700001401939700001601953856006601969 2017 eng d a0003347200aSocial calls honestly signal female competitive ability in Asian particoloured bats0 aSocial calls honestly signal female competitive ability in Asian cJan-05-2017 a101 - 1080 v1273 a

Why a variety of social animals vocalize during agonistic foraging interactions remains obscure. One possibility is that these signals advertise the signaller's competitive ability, playing a role in the defence of food resources, yet there is limited evidence in support of this idea. Here, we used adult female Asian particoloured bats, Vespertilio sinensis, to test whether individual variation in competitive ability when foraging can be explained by social calls. Using synchronized infrared video and audio recording, we monitored bat social vocalizations, dominance rank and weight gain in triads under controlled food conditions. Additionally, subsequent playbacks, consisting of experimental stimuli, echolocation pulses and silence, were presented to feeding bats in a laboratory. Analyses showed that females uttered low-frequency social calls composed of one to five syllable types during feeding competition. The rates of social vocalizations increased with reduced food availability. Interestingly, dominance score and weight gain correlated weakly with body size, but positively with call rate and associated parameters. Playback of social calls inhibited the visits of bats to the focal food dish compared to playback of silence and echolocation pulses. The amount of food consumed was greatly reduced in the presence of experimental stimuli versus controls. Collectively, these results highlight that acoustic signals serve as an honest indicator of bat competitive ability.

10aaggressive interaction10abats10acompetitive ability echolocation10aforaging10asocial call1 aLuo, Bo1 aLu, Guanjun1 aChen, Kelly1 aGuo, Dongge1 aHuang, Xiaobin1 aLiu, Ying1 aFeng, Jiang uhttp://linkinghub.elsevier.com/retrieve/pii/S000334721730084203035nas a2200289 4500008004100000245010500041210006900146260001600215300001400231490000700245520213200252653002302384653000902407653002402416653002002440653002502460100002502485700002502510700002602535700002202561700001802583700002602601700002402627700001802651700002302669856005302692 2014 eng d00aTrophic niche flexibility in Glossophaga soricina: how a nectar seeker sneaks an insect snack0 aTrophic niche flexibility in iGlossophaga soricinai how a nectar cJan-06-2014 a632 - 6410 v283 a

Omnivory enables animals to fill more than one trophic niche, providing access to a wider variety of food resources with potentially higher nutrient value, particularly when resources become scarce. Animals can achieve omnivory using different strategies, for example opportunistic foraging, or switching between multiple trophic niches.

The Neotropical bat Glossophaga soricina (Pallas, 1766) is a common and widespread species known for nectar feeding, but it also eats fruit and insects. Approaching stationary objects (flowers and fruits) or moving objects (insects) poses different sensory tasks and should require different echolocation behaviours. Here we tested the contrasting hypothesis that G. soricina can approach both stationary and moving objects using the same echolocation behaviour, thus feeding at different trophic levels by a single sensory mechanism.

Using DNA barcoding, we demonstrate that G. soricina eats beetles (Coleoptera), flies (Diptera) and noctuid moths with bat-detecting ears. Laboratory observations show that G. soricina actively hunts for prey so insect consumption does not appear to be opportunistic. After capture, individuals consumed prey while perched and manipulated them with jaw, thumb, wrist and wing movements, but food handling was longer and chewing rate slower than in obligate insectivores.

In contrast to most insectivorous bats, the echolocation calls of G. soricina are of high frequency and low intensity, and G. soricina did not produce feeding buzzes when approaching insects. An acoustic model of detection distances shows that its low-intensity calls fail to trigger the auditory neurons of eared moths, allowing G. soricina to overcome auditory prey defences.

Individuals achieved niche flexibility using a unique but generalist behavioural approach rather than employing two different specialist methods. Our findings provide a novel insight into the functional mechanisms of insect capture in G. soricina and highlight the importance of considering niche flexibility in classifying trophic links in ecological communities.

10aacoustic modelling10abats10amolecular scatology10apredator–prey10astealth echolocation1 aClare, Elizabeth, L.1 aGoerlitz, Holger, R.1 aDrapeau, Violaine, A.1 aAdams, Amanda, M.1 aNagel, Juliet1 aDumont, Elizabeth, R.1 aHebert, Paul, D. N.1 aFenton, Brock1 aKonarzewski, Marek uhttp://doi.wiley.com/10.1111/fec.2014.28.issue-301826nas a2200217 4500008004100000022001400041245004200055210004100097260002000138300002400158490000600182520116800188653001401356653000901370653001701379653001501396653001601411100001901427700002101446856014101467 2013 eng d a1744-956100aHawkmoths produce anti-bat ultrasound0 aHawkmoths produce antibat ultrasound cNov-20-20132082 a20130161 - 201301610 v93 a

Bats and moths have been engaged in aerial warfare for nearly 65 Myr. This arms race has produced a suite of counter-adaptations in moths, including bat-detecting ears. One set of defensive strategies involves the active production of sound; tiger moths' ultrasonic replies to bat attack have been shown to startle bats, warn the predators of bad taste and jam their biosonar. Here, we report that hawkmoths in the Choerocampina produce entirely ultrasonic sounds in response to tactile stimulation and the playback of biosonar attack sequences. Males do so by grating modified scraper scales on the outer surface of the genital valves against the inner margin of the last abdominal tergum. Preliminary data indicate that females also produce ultrasound to touch and playback of echolocation attack, but they do so with an entirely different mechanism. The anti-bat function of these sounds is unknown but might include startling, cross-family acoustic mimicry, warning of unprofitability or physical defence and/or jamming of echolocation. Hawkmoths present a novel and tractable system to study both the function and evolution of anti-bat defences.

10aarms race10abats10aecholocation10aSphingidae10asphinx moth1 aBarber, J., R.1 aKawahara, A., Y. uhttp://rsbl.royalsocietypublishing.org/cgi/doi/10.1098/rsbl.2013.0161https://syndication.highwire.org/content/doi/10.1098/rsbl.2013.016103163nas a2200277 4500008004100000022001300041245009800054210006900152260001600221300001400237490000800251520229700259653002702556653000902583653001402592653001602606653001802622653001702640653004202657653003802699653001802737653002102755100001802776700002502794856006602819 2017 eng d a0003347200aTo seek or speak? Dual function of an acoustic signal limits its versatility in communication0 aTo seek or speak Dual function of an acoustic signal limits its  cJan-05-2017 a135 - 1520 v1273 a

The perception of different attributes of conspecifics is an integral part of intraspecific communication. It can facilitate the recognition of interaction partners or the assessment of potential mates. Acoustic signals can encode fine-scaled information through the interplay of acoustic variability and specificity. A reliable vocal signature is both unique within a class and variable between classes. Therefore, acoustic complexity might be associated with the number of classes to be discriminated. We investigated the assumption that limitations to signal design may affect the communicative functionality of a signal. To do so, we chose a signal with potentially dual functionality which may therefore display such limitations. In bats, echolocation is used primarily for foraging and orientation but there is increasing support for its additional role in communication. An acoustic analysis of echolocation pulses of the bat Rhinolophus clivosus confirmed sex and individual vocal signatures in echolocation pulses. A habituation–dishabituation playback experiment suggested that bats perceived these signatures because listening bats clearly discriminated between the sexes (two classes) and between individuals (representatives of a multiclass category), although to different degrees. The simple acoustic structure of these vocalizations provides sufficient specificity for sex discrimination but has limitations for individual discrimination because pulse parameters of individuals increasingly overlapped with increasing group size. We conclude that selection for the primary function of echolocation restricts the acoustic space available for communication. However, we frequently observed echolocation pulses with conspicuous structural modifications. Statistical analyses revealed that these vocalizations yielded increased individual distinctiveness. Such added systematic variation may indicate a communicative function and perhaps a signalling intent of the emitter, although the latter has yet to be tested. The findings suggest that the required specificity for effective communication could be obtained through modification of echolocation variants when adaptations for orientation and foraging constrain the evolution of complex communication signatures.

10aacoustic communication10abats10aco-option10aconstraints10aeavesdropping10aecholocation10ahabituation–dishabituation playback10aindividual and sex discrimination10asignal design10avocal signatures1 aBastian, Anna1 aJacobs, David, Steve uhttp://linkinghub.elsevier.com/retrieve/pii/S0003347217300775