@article {58203, title = {Bats and moths: what is there left to learn?}, year = {2003}, abstract = {

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\&$\#$39;s hearing. The nature of this interaction is reviewed. In particular, the role of the echolocation calls of bats in the shaping of the structure, neurophysiology and behavioural responses of moths is discussed. Unresolved issues, such as the structural complexity of the moth\&$\#$39;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.

}, doi = {10.1111/pen.2003.28.issue-410.1111/j.1365-3032.2003.00355.x}, url = {http://www.blackwell-synergy.com/toc/pen/28/4}, author = {Waters, Dean A.} } @article {58052, title = {Use of vocal signatures for the inventory of free-flying Neotropical bats}, journal = {BiotropicaBiotropica}, volume = {31}, number = {3}, year = {1999}, pages = {507-516}, abstract = {

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.

}, keywords = {acoustic identification, Anabat, bats, Bauerus dubiaquercus, Chiroptera, diversity assessment, Emballonuridae, Eptesicus furinalis, inventory, Mormoopidae, Mormoops megalophylla, Myotis elegans, Neotropics, Noctilio leporinus, Pteronotus davyi, Pteronotus parnellii, Pteronotus personatus, Rhogeessa tumida, Saccopteryx bilineata, Saccopteryx leptura}, author = {O{\textquoteright}Farrell, Michael J. and Miller, Bruce W.} } @article {58051, title = {Qualitative Identification of Free-flying Bats Using the Anabat Detector}, journal = {Journal of MammalogyJournal of Mammalogy}, volume = {80}, number = {1}, year = {1999}, note = {JRS}, pages = {11-23}, abstract = {

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.

}, keywords = {Anabat, bats, Chiroptera, echolocation, Eptesicus furinalis, identification, Lasionycteris noctivagans, Lasiurus cinereus, Lasiurus ega, Molossus ater, Molossus molossus, Molossus sinaloae, Myotis californicus, Myotis ciliolabrum, Myotis yumanensis, Noctilio leporinus, Saccopteryx bilineata, Tadarida brasiliensis, technique, vocal signatures}, author = {O{\textquoteright}Farrell, Michael J. and Miller, Bruce W. and Gannon, William L.} } @article {57961, title = {Lasiurus varius (Chiroptera: Vespertilionidae)}, year = {2019}, abstract = {

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.

}, doi = {10.1093/mspecies/sez016}, url = {https://academic.oup.com/mspecies/article/51/983/119/5661032}, author = {Ossa, Gonzalo and D{\'\i}az, M M{\'o}nica and Barquez, Rub{\'e}n M}, editor = {Kilpatrick, C William and Hamilton, Meredith J} } @article {57588, title = {High Throughput Bioacoustic Monitoring and Phenology of the Greater Noctule Bat (Nyctalus lasiopterus) Compared to Other Migratory Species}, year = {2019}, abstract = {

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 {\v C}ervenohorsk\é Saddle in Jesen\íky 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.

}, doi = {10.3161/15081109ACC2019.21.1.006}, url = {https://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.full}, author = {Bartoni{\v c}ka, Tom{\'a}{\v s} and Miketov{\'a}, Nikola and Hulva, Pavel} } @article {57392, title = {Social calls of Myotis nattereri during swarming: Call structure mirrors the different behavioral context}, year = {2019}, abstract = {

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.

}, doi = {10.1371/journal.pone.0221792}, url = {http://dx.plos.org/10.1371/journal.pone.0221792}, author = {Schmidbauer, Philipp and Denzinger, Annette}, editor = {Jon T. Sakata} } @article {53581, title = {Acoustic signalling of aggressive intent in the agonistic encounters of female Asian particoloured bats}, journal = {Animal Behaviour}, volume = {149}, year = {2019}, month = {Jan-03-2019}, pages = {65 - 75}, abstract = {

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.

}, keywords = {aggressive intent, aggressive vocalizations, skin temperature}, issn = {00033472}, doi = {10.1016/j.anbehav.2019.01.012}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0003347219300132}, author = {Zhao, Xin and Jiang, Tinglei and Liu, Heng and Wang, Yuze and Liu, Ying and Feng, Jiang} } @article {53527, title = {Bats increase vocal amplitude and decrease vocal complexity to mitigate noise interference during social communication}, journal = {Animal Cognition}, year = {2019}, month = {Oct-01-2019}, abstract = {

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.

}, keywords = {acoustic communication, bats, Noise, Social calls, vocal plasticity}, issn = {1435-9448}, doi = {10.1007/s10071-018-01235-0}, url = {http://link.springer.com/10.1007/s10071-018-01235-0}, author = {Jiang, Tinglei and Guo, Xiong and Lin, Aiqing and Wu, Hui and Sun, Congnan and Feng, Jiang and Kanwal, Jagmeet S.} } @article {53434, title = {Social vocalizations of big-footed myotis (Myotis macrodactylus) during foraging}, journal = {Integrative Zoology}, year = {2018}, month = {Feb-12-2020}, abstract = {

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.

}, keywords = {bats, foraging, Social calls, Spectro-temporal features}, doi = {10.1111/1749-4877.12367}, url = {http://doi.wiley.com/10.1111/1749-4877.12367}, author = {Guo, Dongge and Luo, Bo and Zhang, Kangkang and LIU, Muxun and Metzner, Walter and Liu, Ying and Feng, Jiang} } @article {53350, title = {Acoustic similarity elicits responses to heterospecific distress calls in bats (Mammalia: Chiroptera)}, journal = {Animal Behaviour}, volume = {146}, year = {2018}, month = {Jan-12-2018}, pages = {143 - 154}, abstract = {

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.

}, keywords = {acoustic similarity, bat, distress call, interspecific eavesdropping, learning, peak frequency, phylogenetic relatedness}, issn = {00033472}, doi = {10.1016/j.anbehav.2018.10.018}, url = {https://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/plain}, author = {Huang, Xiaobin and Metzner, Walter and Zhang, Kangkang and Wang, Yujuan and Luo, Bo and Sun, Congnan and Jiang, Tinglei and Feng, Jiang} } @article {53289, title = {Resource Ephemerality Drives Social Foraging in Bats}, journal = {Current Biology}, year = {2018}, month = {Jan-11-2018}, abstract = {

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.

}, keywords = {bat, behavioral ecology, echolocation, foraging, GPS, movement ecology, navigation, sociobiology}, issn = {09609822}, doi = {10.1016/j.cub.2018.09.064}, url = {https://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/plain}, author = {Egert-Berg, Katya and Hurme, Edward R. and Greif, Stefan and Goldstein, Aya and Harten, Lee and Herrera M., Luis Gerardo and Flores-Mart{\'\i}nez, Jos{\'e} Juan and Vald{\'e}s, Andrea T. and Johnston, Dave S. and Eitan, Ofri and Borissov, Ivo and Shipley, Jeremy Ryan and Medellin, Rodrigo A. and Wilkinson, Gerald S. and Goerlitz, Holger R. and Yovel, Yossi} } @article {53241, title = {A 2.6-gram sound and movement tag for studying the acoustic scene and kinematics of echolocating bats}, journal = {Methods in Ecology and Evolution}, year = {2018}, month = {Apr-10-2019}, abstract = {

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\&$\#$39;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.

}, keywords = {Accelerometers, archival tag, auditory scene, bat echolocation, biologging, echogram, echoic scene, flight kinematics, inertial sensors, sensory-motor response}, doi = {10.1111/2041-210X.13108}, url = {http://doi.wiley.com/10.1111/2041-210X.13108}, author = {Stidsholt, Laura and Johnson, Mark and Beedholm, Kristian and Jakobsen, Lasse and Kugler, Kathrin and Brinkl{\o}v, Signe and Salles, Angeles and Moss, Cynthia F.} } @article {53088, title = {Body size information in large-scale acoustic bat databases}, journal = {PeerJ}, volume = {6}, year = {2018}, month = {Jan-01-2018}, pages = {e5370}, abstract = {

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.

}, doi = {10.7717/peerj.5370}, url = {https://peerj.com/articles/5370}, author = {Penone, Caterina and Kerbiriou, Christian and Julien, Jean-Fran{\c c}ois and Marmet, Julie and Le Viol, Isabelle} } @article {50497, title = {Social calls honestly signal female competitive ability in Asian particoloured bats}, journal = {Animal Behaviour}, volume = {127}, year = {2017}, month = {Jan-05-2017}, pages = {101 - 108}, abstract = {

Why a variety of social animals vocalize during agonistic foraging interactions remains obscure. One possibility is that these signals advertise the signaller\&$\#$39;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.

}, keywords = {aggressive interaction, bats, competitive ability echolocation, foraging, social call}, issn = {00033472}, doi = {10.1016/j.anbehav.2017.03.012}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0003347217300842}, author = {Luo, Bo and Lu, Guanjun and Chen, Kelly and Guo, Dongge and Huang, Xiaobin and Liu, Ying and Feng, Jiang} } @article {48152, title = {An Aerial-Hawking Bat Uses Stealth Echolocation to Counter Moth Hearing}, journal = {Current Biology}, volume = {20}, year = {2010}, month = {Jan-09-2010}, pages = {1568 - 1572}, abstract = {

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.

}, issn = {09609822}, doi = {10.1016/j.cub.2010.07.046}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0960982210009917}, author = {Goerlitz, Holger R. and ter Hofstede, Hannah M. and Zeale, Matt R.K. and Jones, Gareth} } @article {48149, title = {Interspecific acoustic recognition in two European bat communities}, journal = {Frontiers in Physiology}, volume = {4}, year = {2013}, month = {Jan-01-2013}, abstract = {

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.

}, keywords = {acoustic communication, eavesdropping, echolocation, feeding buzz, interspecific communication, intraspecific communication, search calls}, doi = {10.3389/fphys.2013.00192}, url = {http://journal.frontiersin.org/article/10.3389/fphys.2013.00192/abstract}, author = {Dorado-Correa, Adriana M. and Goerlitz, Holger R. and Siemers, Bj{\"o}rn M.} } @article {47814, title = {Three-dimensional sonar beam-width expansion by Japanese house bats ( Pipistrellus abramus ) during natural foraging}, journal = {The Journal of the Acoustical Society of America}, volume = {141}, year = {2017}, month = {Jan-05-2017}, pages = {EL439 - EL444}, abstract = {

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.

}, issn = {0001-4966}, doi = {10.1121/1.4981934}, url = {http://asa.scitation.org/doi/10.1121/1.4981934}, author = {Motoi, Kazuya and Sumiya, Miwa and Fujioka, Emyo and Hiryu, Shizuko} }