01757nas a2200097 4500008004100000245004900041210004700090520145100137100002101588856005001609 2003 eng d00aBats and moths: what is there left to learn?0 aBats and moths what is there left to learn3 a

Over 14 families of moths have ears that are adapted to detect the ultrasonic echolocation calls of bats. On hearing a bat, these moths respond with an escape response that reduces their chances of being caught. As an evolutionary response, bats may then have evolved behavioural strategies or changes in call design to overcome the moth's hearing. The nature of this interaction is reviewed. In particular, the role of the echolocation calls of bats in the shaping of the structure, neurophysiology and behavioural responses of moths is discussed. Unresolved issues, such as the structural complexity of the moth's auditory system, the nature of temporal integration and the role of the non‐auditory B cell, are described. Issues in which the interactions between bats and moths may be of more general interest to biologists, such as noise filtering within the central nervous system, protean behaviours and coevolution between predator and prey, are also discussed. The interaction between bats and moths has much to interest general biologists, and may provide a useful model in understanding the neurophysiological basis of behaviour, including protean escape behaviours. The validity of the term coevolution as applied to this system is discussed, as there is no doubt that the auditory system of moths is a response to the echolocation calls of bats, although the evolutionary response of bats to moths is more ambiguous.

1 aWaters, Dean, A. uhttp://www.blackwell-synergy.com/toc/pen/28/400922nas a2200145 4500008004100000245005100041210004800092520046100140100001800601700001900619700002300638700002400661700002600685856006500711 2019 eng d00aLasiurus varius (Chiroptera: Vespertilionidae)0 aLasiurus varius Chiroptera Vespertilionidae3 a

Lasiurus varius (Poeppig, 1835) is a vespertilionid bat commonly known as Chilean red bat or cinnamon red bat. L. varius is characterized by its deep reddish coloration without frosted appearance, and by the uropatagium covered with long hairs that extend beyond the trailing edge, which clearly distinguishes it from the other species in the genus. The distribution of this rare species is restricted to the southern parts of Argentina and Chile.

1 aOssa, Gonzalo1 aDíaz, Mónica1 aBarquez, Rubén, M1 aKilpatrick, William1 aHamilton, Meredith, J uhttps://academic.oup.com/mspecies/article/51/983/119/566103202609nas a2200121 4500008004100000245014300041210006900184520195900253100002502212700002202237700001702259856021102276 2019 eng d00aHigh Throughput Bioacoustic Monitoring and Phenology of the Greater Noctule Bat (Nyctalus lasiopterus) Compared to Other Migratory Species0 aHigh Throughput Bioacoustic Monitoring and Phenology of the Grea3 a

Conventional monitoring tools are seldom effective for studying the ecology of rare and elusive mammals. In the present study, we use automated ultrasound detectors to provide information about seasonal activity of the greater noctule bat (Nyctalus lasiopterus), the largest and one of least known European bats. We selected localities within Central Europe with diverse geomorphological contexts, including rivers of different sizes and mountain passes. The study demonstrates the capability of the automatic recording approach to achieve bioacoustic discrimination of this species, but also pointed to the persistent need of integrating results from automatic classification software applications with the feedback from manual approaches. The high throughput capacity of the assay proved to be efficient, and the regular occurrence of the species was identified at two localities. These locations are associated with two known and intensely used migratory corridors of winged animals going through Vltava River valley and Červenohorské Saddle in Jeseníky mountains, as illustrated also by the activity patterns of other migratory species. Together with the occurrence of spring and autumn peaks in activity, these findings are in concordance with the plesiomorphic condition in pipistrelloid bats, showing also migratory behavior, and represent further indirect evidence of migration of the greater noctule. This pattern could be facilitated by the trophic niche of the species, involving predation of migrating songbirds. Differences in phenology of migratory species observed at particular sites likely mirror position of the locality in relation to migration flyways, seasonal and geographic variation in prey availability and energy demands etc. Further application of bioacoustic monitoring and other tools is necessary to obtain detailed information about the range and movement ecology of the species in higher latitudes.

1 aBartonička, Tomáš1 aMiketová, Nikola1 aHulva, Pavel uhttps://bioone.org/journals/acta-chiropterologica/volume-21/issue-1/15081109ACC2019.21.1.006/High-Throughput-Bioacoustic-Monitoring-and-Phenology-of-the-Greater-Noctule/10.3161/15081109ACC2019.21.1.006.full01980nas a2200121 4500008004100000245011000041210006900151520151800220100002501738700002301763700002001786856005201806 2019 eng d00aSocial calls of Myotis nattereri during swarming: Call structure mirrors the different behavioral context0 aSocial calls of Myotis nattereri during swarming Call structure 3 a

Swarming is a characteristic behavior of bats that occurs in different social contexts. We studied the swarming behavior of Myotis nattereri at a maternity colony and at an autumn swarming site in South-West Germany by using synchronized sound and video recordings. Swarming was always associated with social vocalizations consisting of four frequently occurring call types. Call type A was a short call with a broadband steep-shallow-steep downward frequency modulation. Call type B consisted of two elements beginning with a broadband upward hooked element followed by a steep frequency modulated element. Call type C showed a characteristic rapid downward-upward-downward frequency modulation. Call type D was a long sinusoidal trill-like call with high variability in signal structure. All call types were recorded at the maternity colony, as well as at the autumn swarming site, but the incidence of each call type differed distinctly between the study sites. At the maternity roost, type A calls were most commonly produced. We found evidence for an individual signature in this call type and suggest that this social call has the function of a contact call in Natterer’s bats. At the autumn swarming site, type D calls were the most common social calls; in contrast, this call type was recorded only twice at the maternity roost. The occurrence of trills mainly at the autumn swarming site and their high variability suggests that trills function as male advertisement calls in M. nattereri.

1 aSchmidbauer, Philipp1 aDenzinger, Annette1 aSakata, Jon, T. uhttp://dx.plos.org/10.1371/journal.pone.022179202100nas a2200241 4500008004100000022001300041245010800054210006900162260001600231300001200247490000800259520136000267653002201627653002901649653002101678100001401699700001901713700001401732700001501746700001401761700001601775856006701791 2019 eng d a0003347200aAcoustic signalling of aggressive intent in the agonistic encounters of female Asian particoloured bats0 aAcoustic signalling of aggressive intent in the agonistic encoun cJan-03-2019 a65 - 750 v1493 a

The signals of animal aggressive intent can communicate aggression levels to competitors, thereby settling conflicts at an early stage and thus reducing energy costs. We tested whether aggressive vocalizations of female Asian particoloured bats, Vespertilio sinensis, encode aggressive intent during agonistic encounters that occur whenever an intruder pushes a resident to obtain a more central roosting spot. Our results showed that the number of noisy/tonal syllables of the disturbed bats met the three criteria used to define aggressive intent. First, the number and ratio of tonal syllables were significantly greater when intruders continued to push, and the number and ratio of noisy syllables were significantly greater when they stopped pushing (context criterion). Second, skin temperature related to emotional arousal during aggressive interaction generally increased when intruders stopped pushing but was unchanged or decreased when they continued pushing (predictive criterion). Finally, bats preferentially selected stimuli with more tonal syllables, and they spent more time approaching more noisy syllables in a two-choice playback experiment (response criterion). Thus, we propose that the number of noisy/tonal syllables within aggressive vocalizations of female Asian particoloured bats functions to signal aggressive intent.

10aaggressive intent10aaggressive vocalizations10askin temperature1 aZhao, Xin1 aJiang, Tinglei1 aLiu, Heng1 aWang, Yuze1 aLiu, Ying1 aFeng, Jiang uhttps://linkinghub.elsevier.com/retrieve/pii/S000334721930013202507nas 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/10.1111/1749-4877.1236702894nas a2200313 4500008004100000022001300041245010600054210006900160260001600229300001400245490000800259520179700267653002402064653000802088653001802096653003202114653001302146653001902159653002902178100001902207700002002226700002002246700001702266700001202283700001702295700001902312700001602331856023302347 2018 eng d a0003347200aAcoustic similarity elicits responses to heterospecific distress calls in bats (Mammalia: Chiroptera)0 aAcoustic similarity elicits responses to heterospecific distress cJan-12-2018 a143 - 1540 v1463 a

Frequently, individuals of one species respond to alarm calls produced by another species. This form of interspecies communication can be critical for survival. How animals recognize and respond to heterospecific alarm calls is, however, still poorly understood. This is especially true for bats, which are highly vocal and possess a specialized auditory system. We hypothesized that, among bat species, acoustic similarity between heterospecific and conspecific alarm calls is a key factor that underlies call recognition. However, this ability could also be acquired via associative learning from prior exposure or result from phylogenetic relatedness among caller and receiver species, as shown by others. Here we focused on distress calls of bats as representing a certain type of alarm call. To test our hypothesis, we recorded distress calls of 11 bat species from four families at five different sites. We broadcast the recorded calls to three of these species (Rhinolophus sinicus, Myotis badius and Myotis laniger). For all three species, neither prior exposure (familiarity) nor phylogenetic relatedness explained the variation in the response strength, as measured by echolocation vocalizations of receiver species in response to playback of heterospecific distress calls. In contrast, acoustic similarity, especially in peak frequency, between conspecific and heterospecific distress calls, was positively correlated with response strength in the receiver species. Thus, our findings emphasize that, at least among bats, acoustic similarity is a key factor allowing recognition of heterospecific alarm calls. It remains unclear whether evolutionary, genetic and/or neurophysiological mechanisms entrain an individual to respond selectively to a specific acoustic feature.

10aacoustic similarity10abat10adistress call10ainterspecific eavesdropping10alearning10apeak frequency10aphylogenetic relatedness1 aHuang, Xiaobin1 aMetzner, Walter1 aZhang, Kangkang1 aWang, Yujuan1 aLuo, Bo1 aSun, Congnan1 aJiang, Tinglei1 aFeng, Jiang uhttps://linkinghub.elsevier.com/retrieve/pii/S0003347218303191https://api.elsevier.com/content/article/PII:S0003347218303191?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0003347218303191?httpAccept=text/plain03094nas a2200397 4500008004100000022001300041245005700054210005700111260001600168520180000184653000801984653002301992653001702015653001302032653000802045653002102053653001502074653001702089100002202106700002202128700001802150700001902168700001602187700002502203700003402228700002402262700002302286700001602309700001802325700002602343700002602369700002602395700002502421700001702446856023302463 2018 eng d a0960982200aResource Ephemerality Drives Social Foraging in Bats0 aResource Ephemerality Drives Social Foraging in Bats cJan-11-20183 a

Observations of animals feeding in aggregations are often interpreted as events of social foraging, but it can be difficult to determine whether the animals arrived at the foraging sites after collective search [1, 2, 3, 4] or whether they found the sites by following a leader [5, 6] or even independently, aggregating as an artifact of food availability [7, 8]. Distinguishing between these explanations is important, because functionally, they might have very different consequences. In the first case, the animals could benefit from the presence of conspecifics, whereas in the second and third, they often suffer from increased competition [3, 9, 10, 11, 12, 13]. Using novel miniature sensors, we recorded GPS tracks and audio of five species of bats, monitoring their movement and interactions with conspecifics, which could be inferred from the audio recordings. We examined the hypothesis that food distribution plays a key role in determining social foraging patterns [14, 15, 16]. Specifically, this hypothesis predicts that searching for an ephemeral resource (whose distribution in time or space is hard to predict) is more likely to favor social foraging [10, 13, 14, 15] than searching for a predictable resource. The movement and social interactions differed between bats foraging on ephemeral versus predictable resources. Ephemeral species changed foraging sites and showed large temporal variation nightly. They aggregated with conspecifics as was supported by playback experiments and computer simulations. In contrast, predictable species were never observed near conspecifics and showed high spatial fidelity to the same foraging sites over multiple nights. Our results suggest that resource (un)predictability influences the costs and benefits of social foraging.

10abat10abehavioral ecology10aecholocation10aforaging10aGPS10amovement ecology10anavigation10asociobiology1 aEgert-Berg, Katya1 aHurme, Edward, R.1 aGreif, Stefan1 aGoldstein, Aya1 aHarten, Lee1 aM., Luis, Gerardo He1 aFlores-Martínez, José, Juan1 aValdés, Andrea, T.1 aJohnston, Dave, S.1 aEitan, Ofri1 aBorissov, Ivo1 aShipley, Jeremy, Ryan1 aMedellin, Rodrigo, A.1 aWilkinson, Gerald, S.1 aGoerlitz, Holger, R.1 aYovel, Yossi uhttps://linkinghub.elsevier.com/retrieve/pii/S0960982218312909https://api.elsevier.com/content/article/PII:S0960982218312909?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0960982218312909?httpAccept=text/plain02346nas a2200313 4500008004100000245010600041210006900147260001600216520139500232653001901627653001701646653001901663653002101682653001501703653001301718653001701731653002201748653002101770653002701791100002101818700001801839700002301857700002001880700002001900700002101920700002001941700002201961856004901983 2018 eng d00aA 2.6-gram sound and movement tag for studying the acoustic scene and kinematics of echolocating bats0 a26gram sound and movement tag for studying the acoustic scene an cApr-10-20193 a

1.To study sensorimotor behaviour in wild animals, it is necessary to synchronously record the sensory inputs available to the animal, and its movements. To do this, we have developed a biologging device that can record the primary sensory information and the associated movements during foraging and navigating in echolocating bats.

2.This 2.6 ‐gram tag records the sonar calls and echoes from an ultrasonic microphone, while simultaneously sampling fine‐scale movement in three dimensions from wideband accelerometers and magnetometers. In this study, we tested the tag on an European noctula (Nyctalus noctula) during target approaches and on four big brown bats (Eptesicus fuscus) during prey interception in a flight room.

3.We show that the tag records both the outgoing calls and echoes returning from objects at biologically relevant distances. Inertial sensor data enables the detection of behavioural events such as flying, turning, and resting. In addition, individual wing‐beats can be tracked and synchronized to the bat's sound emissions to study the coordination of different motor events.

4.By recording the primary acoustic flow of bats concomitant with associated behaviours on a very fine time‐scale, this type of biologging method will foster a deeper understanding of how sensory inputs guide feeding behaviours in the wild.

10aAccelerometers10aarchival tag10aauditory scene10abat echolocation10abiologging10aechogram10aechoic scene10aflight kinematics10ainertial sensors10asensory-motor response1 aStidsholt, Laura1 aJohnson, Mark1 aBeedholm, Kristian1 aJakobsen, Lasse1 aKugler, Kathrin1 aBrinkløv, Signe1 aSalles, Angeles1 aMoss, Cynthia, F. uhttp://doi.wiley.com/10.1111/2041-210X.1310802443nas a2200181 4500008004100000245006400041210006300105260001600168300001000184490000600194520191200200100002102112700002502133700002702158700001802185700002202203856003602225 2018 eng d00aBody size information in large-scale acoustic bat databases0 aBody size information in largescale acoustic bat databases cJan-01-2018 ae53700 v63 a

Background
Citizen monitoring programs using acoustic data have been useful for detecting population and community patterns. However, they have rarely been used to study broad scale patterns of species traits. We assessed the potential of acoustic data to detect broad scale patterns in body size. We compared geographical patterns in body size with acoustic signals in the bat species Pipistrellus pipistrellus. Given the correlation between body size and acoustic characteristics, we expected to see similar results when analyzing the relationships of body size and acoustic signals with climatic variables.

Methods
We assessed body size using forearm length measurements of 1,359 bats, captured by mist nets in France. For acoustic analyses, we used an extensive dataset collected through the French citizen bat survey. We isolated each bat echolocation call (n = 4,783) and performed automatic measures of signals, including the frequency of the flattest part of the calls (characteristic frequency). We then examined the relationship between forearm length, characteristic frequencies, and two components resulting from principal component analysis for geographic (latitude, longitude) and climatic variables.

Results
Forearm length was positively correlated with higher precipitation, lower seasonality, and lower temperatures. Lower characteristic frequencies (i.e., larger body size) were mostly related to lower temperatures and northern latitudes. While conducted on different datasets, the two analyses provided congruent results.

Discussion
Acoustic data from citizen science programs can thus be useful for the detection of large-scale patterns in body size. This first analysis offers a new perspective for the use of large acoustic databases to explore biological patterns and to address both theoretical and applied questions.

1 aPenone, Caterina1 aKerbiriou, Christian1 aJulien, Jean-François1 aMarmet, Julie1 aLe Viol, Isabelle uhttps://peerj.com/articles/537002313nas 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/S000334721730084201828nas a2200181 4500008004100000022001300041245007600054210006900130260001600199300001600215490000700231520124800238100002501486700002901511700002201540700001801562856006601580 2010 eng d a0960982200aAn Aerial-Hawking Bat Uses Stealth Echolocation to Counter Moth Hearing0 aAerialHawking Bat Uses Stealth Echolocation to Counter Moth Hear cJan-09-2010 a1568 - 15720 v203 a

Ears evolved in many nocturnal insects, including some moths, to detect bat echolocation calls and evade capture [1, 2]. Although there is evidence that some bats emit echolocation calls that are inconspicuous to eared moths, it is difficult to determine whether this was an adaptation to moth hearing or originally evolved for a different purpose [2, 3]. Aerial-hawking bats generally emit high-amplitude echolocation calls to maximize detection range [4, 5]. Here we present the first example of an echolocation counterstrategy to overcome prey hearing at the cost of reduced detection distance. We combined comparative bat flight-path tracking and moth neurophysiology with fecal DNA analysis to show that the barbastelle, Barbastella barbastellus, emits calls that are 10 to 100 times lower in amplitude than those of other aerial-hawking bats, remains undetected by moths until close, and captures mainly eared moths. Model calculations demonstrate that only bats emitting such low-amplitude calls hear moth echoes before their calls are conspicuous to moths. This stealth echolocation allows the barbastelle to exploit food resources that are difficult to catch for other aerial-hawking bats emitting calls of greater amplitude.

1 aGoerlitz, Holger, R.1 aHofstede, Hannah, M. ter1 aZeale, Matt, R.K.1 aJones, Gareth uhttp://linkinghub.elsevier.com/retrieve/pii/S096098221000991702456nas a2200229 4500008004100000245007100041210006900112260001600181490000600197520170600203653002701909653001801936653001701954653001701971653003201988653003202020653001702052100003102069700002502100700002402125856007702149 2013 eng d00aInterspecific acoustic recognition in two European bat communities0 aInterspecific acoustic recognition in two European bat communiti cJan-01-20130 v43 a

Echolocating bats emit echolocation calls for spatial orientation and foraging. These calls are often species-specific and are emitted at high intensity and repetition rate. Therefore, these calls could potentially function in intra- and/or inter-specific bat communication. For example, bats in the field approach playbacks of conspecific feeding buzzes, probably because feeding buzzes indicate an available foraging patch. In captivity, some species of bats recognize and distinguish the echolocation calls of different sympatric species. However, it is still unknown if and how acoustic species-recognition mediates interspecific interactions in the field. Here we aim to understand eavesdropping on bat echolocation calls within and across species boundaries in wild bats. We presented playbacks of conspecific and heterospecific search calls and feeding buzzes to four bat species with different foraging ecologies. The bats were generally more attracted by feeding buzzes than search calls and more by the calls of conspecifics than their heterospecifics. Furthermore, bats showed differential reaction to the calls of the heterospecifics. In particular, <i>Myotis capaccinii</i> reacted equally to the feeding buzzes of conspecifics and to ecologically more similar heterospecifics. Our results confirm eavesdropping on feeding buzzes at the intraspecific level in wild bats and provide the first experimental quantification of potential eavesdropping in European bats at the interspecific level. Our data support the hypothesis that bat echolocation calls have a communicative potential that allows interspecific, and potentially intraspecific, eavesdropping in the wild.

10aacoustic communication10aeavesdropping10aecholocation10afeeding buzz10ainterspecific communication10aintraspecific communication10asearch calls1 aDorado-Correa, Adriana, M.1 aGoerlitz, Holger, R.1 aSiemers, Björn, M. uhttp://journal.frontiersin.org/article/10.3389/fphys.2013.00192/abstract01367nas a2200181 4500008004100000022001400041245014200055210006900197260001600266300001800282490000800300520075400308100001801062700001701080700001801097700001901115856005101134 2017 eng d a0001-496600aThree-dimensional sonar beam-width expansion by Japanese house bats ( Pipistrellus abramus ) during natural foraging0 aThreedimensional sonar beamwidth expansion by Japanese house bat cJan-05-2017 aEL439 - EL4440 v1413 a

Three-dimensional directivity patterns of sonar sounds emitted by Japanese house bats (Pipistrellus abramus) during natural foraging were measured by a 44-channel microphone array. Just before prey capture, the terminal frequency (TF) of emitted sounds decreased, and the beam width (mean ± standard deviation) expanded from 40 ± 10° to 63 ± 9° (horizontal) and from 32 ± 10° to 52 ± 7° (vertical). P. abramus decrease the TF to simultaneously expand the beam width in both the horizontal and vertical planes, while retaining the target within the three-dimensional acoustic field of view at the final stage of capture.

1 aMotoi, Kazuya1 aSumiya, Miwa1 aFujioka, Emyo1 aHiryu, Shizuko uhttp://asa.scitation.org/doi/10.1121/1.4981934