02178nas a2200217 4500008004100000022001400041245009300055210006900148260001600217520146300233100001601696700002101712700002401733700002701757700001601784700002601800700002601826700002001852700002601872856006201898 2019 eng d a0824-046900aSeasonal variation in Arctic marine mammal acoustic detection in the northern Bering Sea0 aSeasonal variation in Arctic marine mammal acoustic detection in cDec-12-20203 a

Declines in Arctic sea ice cover are influencing the distribution of protected endemic marine mammals, many of which are important for local Indigenous Peoples, and increasing the presence of potentially disruptive industrial activities. Due to increasing conservation concerns, we conducted the first year‐round acoustic monitoring of waters off Gambell and Savoonga (St. Lawrence Island, Alaska), and in the Bering Strait to quantify vocalizing presence of bowhead whales, belugas, walruses, bearded seals, and ribbon seals. Bottom‐mounted archival acoustic recorders collected data for up to 10 months per deployment between 2012 and 2016. Spectrograms were analyzed for species‐typical vocalizations, and daily detection rates and presence/absence were calculated. Generalized additive models were used to model call presence as a function of time‐of‐year, sea surface temperature, and sea ice concentration. We identified seasonality in call presence for all species, corroborating previous acoustic and distribution studies, and identified finer‐scale spatiotemporal distribution via occurrence of call presence between different monitoring sites. Time‐of‐year was the strongest significant effect on call presence for all species. These data provide important information on Arctic endemic species' spatiotemporal distributions in biologically and culturally important areas within a rapidly changing Arctic region.

1 aChou, Emily1 aAntunes, Ricardo1 aSardelis, Stephanie1 aStafford, Kathleen, M.1 aWest, Leigh1 aSpagnoli, Christopher1 aSouthall, Brandon, L.1 aRobards, Martin1 aRosenbaum, Howard, C. uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/mms.1265801721nas a2200229 4500008004100000022001400041245011400055210006900169260001600238300001600254490000800270520098500278100002201263700001901285700002001304700002201324700002601346700002101372700002701393700002001420856005101440 2019 eng d a0001-496600aThe use of seal scarers as a protective mitigation measure can induce hearing impairment in harbour porpoises0 ause of seal scarers as a protective mitigation measure can induc cJan-12-2019 a4288 - 42980 v1463 a

Acoustic deterrent devices (ADDs) are used to deter seals from aquacultures but exposure of harbour porpoises (Phocoena phocoena) occurs as a side-effect. At construction sites, by contrast, ADDs are used to deter harbour porpoises from the zone in which pile driving noise can induce temporary threshold shifts (TTSs). ADDs emit such high pressure levels that there is concern that ADDs themselves may induce a TTS. A harbour porpoise in human care was exposed to an artificial ADD signal with a peak frequency of 14 kHz. A significant TTS was found, measured by auditory evoked potentials, with an onset of 142 dB re 1 μPa2s at 20 kHz and 147 dB re 1 μPa2s at 28 kHz. The authors therefore strongly recommend to gradually increase and down regulate source levels of ADDs to the desired deterrence range. However, further research is needed to develop a reliable relationship between received levels and deterrence.

1 aSchaffeld, Tobias1 aRuser, Andreas1 aWoelfing, Benno1 aBaltzer, Johannes1 aKristensen, Jakob, H.1 aLarsson, Josefin1 aSchnitzler, Joseph, G.1 aSiebert, Ursula uhttp://asa.scitation.org/doi/10.1121/1.513530301503nas a2200241 4500008004100000245013800041210006900179520065400248100002000902700001600922700003100938700003100969700002401000700002001024700002101044700002501065700002201090700002401112700002601136700002101162700002701183856005101210 2019 eng d00aSong structure and singing activity of two separate humpback whales populations wintering off the coast of Caño Island in Costa Rica0 aSong structure and singing activity of two separate humpback wha3 a

Central American (CA) and Breeding Stock-G (BSG) humpback whales are known to winter off Caño Island, Costa Rica at different times of the year. To study their singing behavior, autonomous underwater recorders were used to record the whales. Song detection for BSG whales was higher than CA whales, and song structure was distinct for each population. No strong evidence for cross-equatorial connectivity was found. This study provides the first humpback whale song reference for both populations in Costa Rica, which can help advance understanding of CA and BSG whale song rate of change and connectivity with other wintering areas.

1 aChereskin, Emma1 aBeck, Lucas1 aGamboa-Poveda, Mónica, P.1 aPalacios-Alfaro, José, D.1 aMonge-Arias, Ronald1 aChase, Alex, R.1 aCoven, Brian, M.1 aGuzmán, Ana, Gloria1 aMcManus, Noah, W.1 aNeuhaus, Alyssa, P.1 aO'Halloran, Riley, A.1 aRosen, Sasha, G.1 aMay-Collado, Laura, J. uhttp://asa.scitation.org/doi/10.1121/1.513920502590nas a2200145 4500008004100000245012300041210006900164520206400233100002102297700001902318700001802337700001902355700001602374856005402390 2019 eng d00aVocal individuality of Holstein-Friesian cattle is maintained across putatively positive and negative farming contexts0 aVocal individuality of HolsteinFriesian cattle is maintained acr3 a

Cattle mother-offspring contact calls encode individual-identity information; however, it is unknown whether cattle are able to maintain individuality when vocalising to familiar conspecifics over other positively and negatively valenced farming contexts. Accordingly, we recorded 333 high-frequency vocalisations from 13 Holstein-Friesian heifers during oestrus and anticipation of feed (putatively positive), as well as denied feed access and upon both physical and physical & visual isolation from conspecifics (putatively negative). We measured 21 source-related and nonlinear vocal parameters and stepwise discriminant function analyses (DFA) were performed. Calls were divided into positive (n = 170) and negative valence (n = 163) with each valence acting as a ‘training set’ to classify calls in the oppositely valenced ‘test set’. Furthermore, MANOVAs were conducted to determine which vocal parameters were implicated in individual distinctiveness. Within the putatively positive ‘training set’, the cross-validated DFA correctly classified 68.2% of the putatively positive calls and 52.1% of the putatively negative calls to the correct individual, respectively. Within the putatively negative ‘training set’, the cross-validated DFA correctly assigned 60.1% of putatively negative calls and 49.4% of putatively positive calls to the correct individual, respectively. All DFAs exceeded chance expectations indicating that vocal individuality of high-frequency calls is maintained across putatively positive and negative valence, with all vocal parameters except subharmonics responsible for this individual distinctiveness. This study shows that cattle vocal individuality of high-frequency calls is stable across different emotionally loaded farming contexts. Individual distinctiveness is likely to attract social support from conspecifics, and knowledge of these individuality cues could assist farmers in detecting individual cattle for welfare or production purposes.

1 aGreen, Alexandra1 aClark, Cameron1 aFavaro, Livio1 aLomax, Sabrina1 aReby, David uhttp://www.nature.com/articles/s41598-019-54968-401785nas a2200217 4500008004100000245012800041210006900169520098500238653002201223653001201245653001701257653003401274653001801308653001501326653000801341653002201349653001601371100002001387700002401407856013601431 2019 eng d00aAcoustically estimated size distribution of sperm whales ( Physeter macrocephalus) off the east coast of New Zealand0 aAcoustically estimated size distribution of sperm whales iPhyset3 a

The length-frequency distribution of sperm whales (Physeter macrocephalus) was studied on the east coast of NZ using passive acoustic recorders moored offshore of Kaikoura, Cape Palliser and Castlepoint. Sperm whale’s echolocation signals are unique among odontocete species. Their clicks are composed by multiple pulses resulting from the sound transmission within the whale head. The total length of the whales can be estimated by measuring the time delay between these pulses. A total of 997 length measurements were obtained from click trains using cepstral analysis (mean = 14.6 m; min = 9.6 m; max = 18.3 m; std = 1 m). The size-frequency distributions at all three locations were similar, although animals smaller than 12 m were not present offshore of Kaikoura. Animals of various sizes appeared to be present all year round, with no apparent seasonality in the occurrence of any size class.

10acepstral analysis10aceptrum10aecholocation10alength-frequency distribution10amarine mammal10aodontocete10aPAM10apassive acoustics10asperm whale1 aGiorli, Giacomo1 aGoetz, Kimberly, T. uhttps://www.tandfonline.com/doi/full/10.1080/00288330.2019.1679843https://www.tandfonline.com/doi/pdf/10.1080/00288330.2019.167984301461nas a2200109 4500008004100000245009700041210006900138520104600207100002001253700002401273856005401297 2019 eng d00aForaging activity of sperm whales (Physeter macrocephalus) off the east coast of New Zealand0 aForaging activity of sperm whales Physeter macrocephalus off the3 a

The occurrence and distribution of sperm whales in New Zealand waters is mainly known from whaling records or opportunistic sightings by the public and a systematic estimation of the abundance and distribution has never been conducted. In this study, we investigated the foraging activity and occurrence of sperm whales off the Eastern coast of New Zealand using passive acoustic monitoring techniques. Three acoustic recorders were moored to the ocean floor at different locations on the east side of the North and South Island to collect passive acoustic data from June 2016 until August 2017. A total of 53,823 echolocation click trains were recorded and analyzed to understand the spatial and temporal variation of sperm whale foraging activity. No difference in the foraging activity was found between night-time and day-time periods at any of the locations. Click train detections increased toward the south, suggesting increased foraging activity near Kaikoura. At each station, sperm whale foraging activity varied by month.

1 aGiorli, Giacomo1 aGoetz, Kimberly, T. uhttp://www.nature.com/articles/s41598-019-48417-503379nas a2200361 4500008004100000245017400041210006900215520225800284653001202542653001202554653001302566653002602579653002202605653001102627653001302638653001202651653001302663653002102676653001502697653001802712653001602730100001702746700002202763700002402785700002602809700001702835700001802852700002202870700001902892700002302911700002102934856006202955 2019 eng d00aSavannah roars: The vocal anatomy and the impressive rutting calls of male impala (Aepyceros melampus) – highlighting the acoustic correlates of a mobile larynx0 aSavannah roars The vocal anatomy and the impressive rutting call3 a

A retractable larynx and adaptations of the vocal folds in the males of several polygynous ruminants serve for the production of rutting calls that acoustically announce larger than actual body size to both rival males and potential female mates. Here, such features of the vocal tract and of the sound source are documented in another species. We investigated the vocal anatomy and laryngeal mobility including its acoustical effects during the rutting vocal display of free‐ranging male impala (Aepyceros melampus melampus) in Namibia. Male impala produced bouts of rutting calls (consisting of oral roars and interspersed explosive nasal snorts) in a low‐stretch posture while guarding a rutting territory or harem. For the duration of the roars, male impala retracted the larynx from its high resting position to a low mid‐neck position involving an extensible pharynx and a resilient connection between the hyoid apparatus and the larynx. Maximal larynx retraction was 108 mm based on estimates in video single frames. This was in good concordance with 91‐mm vocal tract elongation calculated on the basis of differences in formant dispersion between roar portions produced with the larynx still ascended and those produced with maximally retracted larynx. Judged by their morphological traits, the larynx‐retracting muscles of male impala are homologous to those of other larynx‐retracting ruminants. In contrast, the large and massive vocal keels are evolutionary novelties arising by fusion and linear arrangement of the arytenoid cartilage and the canonical vocal fold. These bulky and histologically complex vocal keels produced a low fundamental frequency of 50 Hz. Impala is another ruminant species in which the males are capable of larynx retraction. In addition, male impala vocal folds are spectacularly specialized compared with domestic bovids, allowing the production of impressive, low‐frequency roaring vocalizations as a significant part of their rutting behaviour. Our study expands knowledge on the evolutionary variation of vocal fold morphology in mammals, suggesting that the structure of the mammalian sound source is not always human‐like and should be considered in acoustic analysis and modelling.

10aBovidae10aFelidae10aformants10afundamental frequency10alarynx retraction10amammal10apolygyny10aroaring10aruminant10asexual selection10avocal fold10avocal posture10avocal tract1 aFrey, Roland1 aVolodin, Ilya, A.1 aVolodina, Elena, V.1 aEfremova, Kseniya, O.1 aMenges, Vera1 aPortas, Ruben1 aMelzheimer, Jörg1 aFritsch, Guido1 aGerlach, Christina1 aDörnberg, Katja uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/joa.1311401972nas a2200157 4500008004100000245011400041210006900155520140900224100002001633700002001653700002401673700002001697700002301717700002301740856005101763 2019 eng d00aSounds associated with foraging and prey capture in individual fish-eating killer whales, Orcinus orca0 aSounds associated with foraging and prey capture in individual f3 a

Foraging behavior in odontocetes is fundamentally tied to the use of sound. Resident-type killer whales use echolocation to locate and capture elusive salmonid prey. In this investigation, acoustic recording tags were suction cup-attached to endangered Southern Resident killer whales to describe their acoustic behavior during different phases of foraging that, along with detections of prey handling sounds (e.g., crunches) and observed predation events, allow confirmation of prey capture. Echolocation click trains were categorized based on the inter-click interval (ICI) according to hypothesized foraging function. Whales produced slow click trains (ICI >100 ms) at shallowest depths but over the largest change of depth, fast click trains (10 ms < ICI ≤100 ms) at intermediate depths, and buzz trains (ICI ≤10 ms) at deepest depths over the smallest depth change. These results align with hypotheses regarding biosonar use to search, pursue and capture prey. Males exhibited a higher probability of producing slow click trains, buzzes and prey handling sounds, indicating higher levels of prey searching and capture to support the energy requirement of their larger body size. These findings identify relevant acoustic indicators of subsurface foraging behaviors of killer whales, enabling investigations of human impacts on sound use and foraging.

1 aHolt, Marla, M.1 aHanson, Bradley1 aEmmons, Candice, K.1 aHaas, David, K.1 aGiles, Deborah, A.1 aHogan, Jeffrey, T. uhttp://asa.scitation.org/doi/10.1121/1.513338801832nas a2200133 4500008004100000245009400041210006900135520134400204100002001548700003001568700002801598700001801626856005401644 2019 eng d00aDeep-diving pilot whales make cheap, but powerful, echolocation clicks with 50 µL of air0 aDeepdiving pilot whales make cheap but powerful echolocation cli3 a

Echolocating toothed whales produce powerful clicks pneumatically to detect prey in the deep sea where this long-range sensory channel makes them formidable top predators. However, air supplies for sound production compress with depth following Boyle’s law suggesting that deep-diving whales must use very small air volumes per echolocation click to facilitate continuous sensory flow in foraging dives. Here we test this hypothesis by analysing click-induced acoustic resonances in the nasal air sacs, recorded by biologging tags. Using 27000 clicks from 102 dives of 23 tagged pilot whales (Globicephala macrorhynchus), we show that click production requires only 50 µL of air/click at 500 m depth increasing gradually to 100 µL at 1000 m. With such small air volumes, the metabolic cost of sound production is on the order of 40 J per dive which is a negligible fraction of the field metabolic rate. Nonetheless, whales must make frequent pauses in echolocation to recycle air between nasal sacs. Thus, frugal use of air and periodic recycling of very limited air volumes enable pilot whales, and likely other toothed whales, to echolocate cheaply and almost continuously throughout foraging dives, providing them with a strong sensory advantage in diverse aquatic habitats.

1 aFoskolos, Ilias1 ade Soto, Natacha, Aguilar1 aMadsen, Peter, Teglberg1 aJohnson, Mark uhttp://www.nature.com/articles/s41598-019-51619-600395nas a2200097 4500008004100000245009300041210006900134100002300203700002000226856005100246 2019 eng d00aTime of arrival difference estimation for narrow band high frequency echolocation clicks0 aTime of arrival difference estimation for narrow band high frequ1 aGillespie, Douglas1 aMacaulay, Jamie uhttp://asa.scitation.org/doi/10.1121/1.512967802957nas a2200181 4500008004100000245018400041210006900225520225300294100001802547700002102565700002202586700002302608700002302631700001902654700001802673700002302691856006102714 2019 eng d00aThe higher, the closer, the better? Influence of sampling frequency and distance on the acoustic properties of short‐beaked common dolphins burst pulses in the Mediterranean Sea0 ahigher the closer the better Influence of sampling frequency and3 a

1. When implementing conservation strategies involving passive acoustic monitoring, an accurate description of signal properties is crucial, especially when studying threatened and elusive vocalizing species. Misrepresentation of detected sounds can result in information loss or misclassification of species, thus compromising the management process.

2. Distortion of the time–frequency features depends on the characteristics of acoustic propagation through sea water, sensitivity and sampling frequency of the acquisition system and distance between cetacean source and the receiving sensor (hydrophone).

3. This study examined how the sampling frequency and the distance from the source affect the properties of burst pulsed sounds emitted by short‐beaked common dolphins in the Mediterranean Sea and how the signal is modified in relation to the recording scenarios.

4. Burst pulses were collected at 300 000 samples/s, and down‐sampled at 192 000, 96 000, 48 000 and 44 100. Fifteen acoustic parameters were automatically measured. The median values were measured and compared among the signals sampled at different rates. Finally, a transmission loss model was applied to explore the variation of the power spectrum density during click propagation through seawater.

5. The results showed that, even if higher sampling rates are a more accurate match with the original signal, some parameters (number of clicks, inter‐click‐interval and maximum peak) measured at 96 000 and 192 000 Hz did not display significant differences compared with 300 000 Hz, except for the frequency parameters. The transmission loss model also showed that the highest frequency components strongly attenuate within 800 m from the source.

6. These results suggest that high recording distances and lower sampling rates do not allow an accurate analysis of burst pulsed signals. However, taking into account data storage limitations, recording at the highest frequency is not always required for an accurate description of signals and the outcomes of this study improve the accuracy of passive acoustic monitoring systems, thus enhancing the potential for conservation of short‐beaked common dolphins.

1 aPapale, Elena1 aAlonge, Giuseppe1 aCaruso, Francesco1 aGrammauta, Rosario1 aMazzola, Salvatore1 aMussi, Barbara1 aPace, Daniela1 aBuscaino, Giuseppa uhttps://onlinelibrary.wiley.com/doi/abs/10.1002/aqc.315801990nas a2200193 4500008004100000245011100041210006900152520132100221653002101542653001701563653001801580653002301598653001601621100002101637700002101658700002601679700002501705856006601730 2019 eng d00aAcoustic crypsis in communication by North Atlantic right whale mother–calf pairs on the calving grounds0 aAcoustic crypsis in communication by North Atlantic right whale 3 a

Mammals with dependent young often rely on cryptic behaviour to avoid detection by potential predators. In the mysticetes, large baleen whales, young calves are known to be vulnerable to direct predation from both shark and orca predators; therefore, it is possible that mother–calf pairs may show cryptic behaviours to avoid the attention of predators. Baleen whales primarily communicate through low-frequency acoustic signals, which can travel over long ranges. In this study, we explore the potential for acoustic crypsis, a form of cryptic behaviour to avoid predator detection, in North Atlantic right whale mother–calf pairs. We predicted that mother– calf pairs would either show reduced calling rates, reduced call amplitude or a combination of these behavioural modifications when compared with other demographic groups in the same habitat. Our results show that right whale mother–calf pairs have a strong shift in repertoire usage, significantly reducing the number of higher amplitude, long-distance communication signals they produced when compared with juvenile and pregnant whales in the same habitat. These observations show that right whale mother–calf pairs rely upon acoustic crypsis, potentially to minimize the risk of acoustic eavesdropping by predators.

10aacoustic crypsis10abaleen whale10aeavesdropping10apredator avoidance10aright whale1 aParks, Susan, E.1 aCusano, Dana, A.1 aVan Parijs, Sofie, M.1 aNowacek, Douglas, P. uhttps://royalsocietypublishing.org/doi/10.1098/rsbl.2019.048501589nas a2200277 4500008004100000022001400041245012100055210006900176260001600245300001800261490000800279520071100287100002200998700002201020700002001042700002101062700002601083700002801109700001701137700001601154700002601170700002101196700001901217700002401236856005101260 2019 eng d a0001-496600aAcoustic recordings of rough-toothed dolphin ( Steno bredanensis) offshore Eastern Sicily (Mediterranean Sea)0 aAcoustic recordings of roughtoothed dolphin iSteno bredanensisi  cJan-09-2019 aEL286 - EL2920 v1463 a

Rough-toothed dolphin's abundance and distribution is largely unknown worldwide and evaluation of its conservation status in the Mediterranean Sea is necessary. A rough-toothed dolphin was sighted offshore Eastern Sicily (Mediterranean Sea) in July 2017 and acoustic data were acquired in the same area of Watkins, Tyack, Moore, and Notarbartolo di Sciara [(1987). Mar. Mamm. Sci. 3, 78–82]. An automatic detection algorithm was developed to identify the echolocation clicks recorded within both datasets and a recurrent inter-click interval value was identified during the new encounter. Distinctive whistle classes were also identified with similar contour shapes within both datasets.

1 aCaruso, Francesco1 aSciacca, Virginia1 aParisi, Ignazio1 aViola, Salvatore1 ade Vincenzi, Giovanni1 aBocconcelli, Alessandro1 aMooney, Aran1 aLi, Songhai1 aFiliciotto, Francesco1 aMoulins, Aurelie1 aTepsich, Paola1 aRosso, Massimiliano uhttp://asa.scitation.org/doi/10.1121/1.512611801962nam a2200289 4500008004100000020002200041245006700063210006700130520111600197653001701313653001401330653001901344653001801363653001701381653000901398653002801407100002001435700002301455700002001478700002301498700002301521700001901544700001801563700001901581700001701600856005501617 2019 eng d a978-3-030-27946-200aDeep Representation Learning for Orca Call Type Classification0 aDeep Representation Learning for Orca Call Type Classification3 a

Marine mammals produce a wide variety of vocalizations. There is a growing need for robust automatic classification methods especially in noisy underwater environments in order to access large amounts of bioacoustic signals and to replace tedious and error prone human perceptual classification. In case of the northern resident killer whale (Orcinus orca), echolocation clicks, whistles, and pulsed calls make up its vocal repertoire. Pulsed calls are the most intensively studied type of vocalization. In this study we propose a hybrid call type classification approach outperforming our previous work on supervised call type classification consisting of two components: (1) deep representation learning of killer whale sounds by investigating various autoencoder architectures and data corpora and (2) subsequent supervised training of a ResNet18 call type classifier on a much smaller dataset by using the pre-trained representations. The best semi-supervised trained classification model achieved a test accuracy of 96% and a mean test accuracy of 94% outperforming our previous work by 7% points.

10abioacoustics10acall type10aclassification10aDeep learning10aKiller whale10aOrca10aRepresentation learning1 aEkštein, Kamil1 aBergler, Christian1 aSchmitt, Manuel1 aCheng, Rachael, Xi1 aSchröter, Hendrik1 aMaier, Andreas1 aBarth, Volker1 aWeber, Michael1 aNöth, Elmar uhttp://link.springer.com/10.1007/978-3-030-27947-902054nas a2200169 4500008004100000245010200041210006900143260001600212490000600228520148700234100002301721700002701744700002101771700001601792700002201808856005401830 2019 eng d00aDeep Machine Learning Techniques for the Detection and Classification of Sperm Whale Bioacoustics0 aDeep Machine Learning Techniques for the Detection and Classific cJan-12-20190 v93 a

We implemented Machine Learning (ML) techniques to advance the study of sperm whale (Physeter macrocephalus) bioacoustics. This entailed employing Convolutional Neural Networks (CNNs) to construct an echolocation click detector designed to classify spectrograms generated from sperm whale acoustic data according to the presence or absence of a click. The click detector achieved 99.5% accuracy in classifying 650 spectrograms. The successful application of CNNs to clicks reveals the potential of future studies to train CNN-based architectures to extract finer-scale details from cetacean spectrograms. Long short-term memory and gated recurrent unit recurrent neural networks were trained to perform classification tasks, including (1) “coda type classification” where we obtained 97.5% accuracy in categorizing 23 coda types from a Dominica dataset containing 8,719 codas and 93.6% accuracy in categorizing 43 coda types from an Eastern Tropical Pacific (ETP) dataset with 16,995 codas; (2) “vocal clan classification” where we obtained 95.3% accuracy for two clan classes from Dominica and 93.1% for four ETP clan types; and (3) “individual whale identification” where we obtained 99.4% accuracy using two Dominica sperm whales. These results demonstrate the feasibility of applying ML to sperm whale bioacoustics and establish the validity of constructing neural networks to learn meaningful representations of whale vocalizations.

1 aBermant, Peter, C.1 aBronstein, Michael, M.1 aWood, Robert, J.1 aGero, Shane1 aGruber, David, F. uhttp://www.nature.com/articles/s41598-019-48909-402041nas a2200169 4500008004100000022001400041245014400055210006900199260001600268300001600284490000800300520146900308100001401777700001401791700001501805856005101820 2019 eng d a0001-496600aA biosonar model of finless porpoise ( Neophocaena phocaenoides ) for material composition discrimination of cylinders0 abiosonar model of finless porpoise iNeophocaena phocaenoidesi fo cJan-08-2019 a1362 - 13700 v1463 a

Research into the physical mechanism of odontocetes biosonar has made great progress in the past several decades, especially on wave propagation and biosonar beam formation in the foreheads of odontocetes. Although a number of experimental studies have been performed, the physical mechanism of odontocetes underwater target discrimination has not yet been fully understood. Previous research has experimentally studied the finless porpoise's target discrimination using cylinders different in material [Nakahara, Takemura, Koido, and Hiruda (1997). Mar. Mamm. Sci. 13(4), 639–649]. The authors proposed a computed tomography based finite element biosonar model to simulate the detailed process of a finless porpoise click emission and target detection in order to gain a further understanding of the underlying physical mechanism. The numerical solutions of resonance features of both steel and acrylic cylinders in this study are very consistent with the analytic solutions. Furthermore, the simulated outgoing clicks and echoes match the experiment results measured by Nakahara et al. The beam patterns of the scattered field were extracted and the resonance features of cylinders in different materials were analyzed. This method in this study could be used to study some other odontocetes that are inaccessible for experimental work and could also provide physical information for intelligent biomimetic underwater signal processors design.

1 aFeng, Wen1 aZhang, Yu1 aWei, Chong uhttp://asa.scitation.org/doi/10.1121/1.512298101898nas a2200121 4500008004100000245008300041210006900124260003900193490000700232520147000239100002101709856004601730 2019 eng d00aVocal Response of Bottlenose Dolphins (Tursiops truncatus) to a Novel Stimulus0 aVocal Response of Bottlenose Dolphins Tursiops truncatus to a No bUniversity of Southern Mississippi0 vMA3 a

Bottlenose dolphins utilize acoustic signals as their primary mode of communication. Although some aspects of dolphin vocal behavior are well understood, less is known about vocalizations in different behavioral contexts and how these vocal behaviors may indicate habituation and sensitization. The focus of this study was to investigate how bottlenose dolphins respond vocally to a novel stimulus. Archival data from three populations of bottlenose dolphins (N = 20) living in a human-care facility were exposed to a novel apparatus (a mirror) for 10 trials, each lasting 20 minutes. Five of the trials presented the mirror covered with an opaque cloth whereas the other five trials left the mirror uncovered, exposing the reflective surface. Rates of two distinct vocal types (whistles and burst pulses) were calculated for each trial. Vocal rates were greater on the last (non-novel) trials versus novel trials—a pattern of sensitization to the novel stimulus. Vocal rates and the degree of sensitization were greater on reflective trials than non-reflective trials. Finally, vocal rates were greater for whistles than burst pulses overall, but sensitization was most apparent with burst pulses. This study identifies how the production of two types of vocalizations change in response to a novel stimulus of varying reflectivity over repeated exposures thereby providing a greater understanding of the contexts in which these utterances are used.

1 aJohnson, Lindsey uhttps://bio.acousti.ca/zh-hans/node/5729502116nas a2200157 4500008004100000245007400041210006900115260001600184300001300200490000700213520162500220100002501845700001601870700002001886856005201906 2019 eng d00aDeer browsing alters sound propagation in temperate deciduous forests0 aDeer browsing alters sound propagation in temperate deciduous fo cJan-02-2020 ae02115690 v143 a

The efficacy of animal signals is strongly influenced by the structure of the habitat in which they are propagating. In recent years, the habitat structure of temperate forests has been increasingly subject to modifications from foraging by white-tailed deer (Odocoileus virginianus). Increasing deer numbers and the accompanying browsing have been shown to alter vegetation structure and thus the foraging, roosting, and breeding habitats of many species. However, despite a large body of literature on the effects of vegetation structure on sound propagation, we do not yet know what impact deer browsing may have on acoustic communication. Here we used playback experiments to determine whether sound fidelity and amplitude of white noise, pure tones, and trills differed between deer-browsed and deer-excluded plots. We found that sound fidelity, but not amplitude, differed between habitats, with deer-browsed habitats having greater sound fidelity than deer-excluded habitats. Difference in sound propagation characteristics between the two habitats could alter the efficacy of acoustic communication through plasticity, cultural evolution or local adaptation, in turn influencing vocally-mediated behaviors (e.g. agonistic, parent-offspring, mate selection). Reduced signal degradation suggests vocalizations may retain more information, improving the transfer of information to both intended and unintended receivers. Overall, our results suggest that deer browsing impacts sound propagation in temperate deciduous forest, although much work remains to be done on the potential impacts on communication.

1 aBoycott, Timothy, J.1 aGao, Jingyi1 aGall, Megan, D. uhttp://dx.plos.org/10.1371/journal.pone.021156901980nas a2200181 4500008004100000245014800041210006900189260001600258490000600274520135900280100001501639700001601654700001901670700001401689700001301703700002801716856005401744 2019 eng d00aLow energy expenditure and resting behaviour of humpback whale mother-calf pairs highlights conservation importance of sheltered breeding areas0 aLow energy expenditure and resting behaviour of humpback whale m cJan-12-20190 v93 a

Understanding the behaviour of humpback whale mother-calf pairs and the acoustic environment on their breeding grounds is fundamental to assessing the biological and ecological requirements needed to ensure a successful migration and survival of calves. Therefore, on a breeding/resting ground, Exmouth Gulf, Western Australia, we used animal-borne DTAGs to quantify the fine-scale behaviour and energetic expenditure of humpback whale mothers and calves, while sound recorders measured the acoustic environment. We show that: (i) lactating humpback whales keep their energy expenditure low by devoting a significant amount of time to rest, and their use of energy, inferred from respiration rates, is ~half than that of adults on their foraging grounds; (ii) lactating females mainly rest while stationary at shallow depths within reach of the hull of commercial ships, thus increasing the potential for ship strike collisions; (iii) the soundscape is dominated by biological sources; and (iv) even moderate increases of noise from vessels will decrease the communication range of humpback whales. Planned commercial infrastructure in Exmouth Gulf will cause a substantial increase in shipping traffic with the risk of ship strikes and acoustic disturbance potentially compromising energy reserves for the southern migration of humpback whales.

1 aBejder, L.1 aVidesen, S.1 aHermannsen, L.1 aSimon, M.1 aHanf, D.1 aMadsen, Peter, Teglberg uhttp://www.nature.com/articles/s41598-018-36870-702471nas a2200157 4500008004100000245014100041210006900182260001600251300001300267490000700280520190900287100002902196700001602225700002002241856005202261 2019 eng d00aSubarctic singers: Humpback whale (Megaptera novaeangliae) song structure and progression from an Icelandic feeding ground during winter0 aSubarctic singers Humpback whale Megaptera novaeangliae song str cNov-01-2020 ae02100570 v143 a

of traditional low latitude breeding grounds. Songs from a subarctic feeding ground during the winter were quantitatively characterized to investigate the structure and temporal changes of the songs at such an atypical location. Recordings were collected from 26. January to 12. March, 2011, using bottom mounted recorders. Humpback songs were detected on 91% of the recording days with peak singing activities during 9.–26. February. The majority of the recordings included multiple chorusing singers. The songs were characterized by a) common static themes which transitioned consistently to predictable themes, b) shifting themes which occurred less predictably and c) rare themes. A set median sequence was found for four different periods (sets) of recordings (approximately 1 week each). The set medians were highly similar and formed a single cluster indicating that the sequences of themes sung in this area belonged to a single cluster of songs despite of the variation caused by the shifting themes. These subarctic winter songs could, thus, represent a characteristic song type for this area which is comparable to extensively studied songs from traditional low latitude breeding grounds. An increase in the number of themes per sequence was observed throughout the recording period including minor changes in the application of themes in the songs; indicating a gradual song progression. The results confirm that continual singing of sophisticated songs occur during the breeding season in the subarctic. In addition to being a well-established summer feeding ground the study area appears to be an important overwintering site for humpback whales delaying or canceling their migration where males engage in active sexual displays, i.e. singing. Importantly, such singing activity on a shared feeding ground likely aids the cultural transmission of songs in the North Atlantic.

1 aMagnúsdóttir, Edda, E.1 aLim, Rangyn1 aSakata, Jon, T. uhttp://dx.plos.org/10.1371/journal.pone.021005702662nas a2200205 4500008004100000245012000041210006900161260001600230300001300246490000700259520196600266100002402232700002502256700002802281700002102309700003302330700002102363700002002384856005202404 2019 eng d00aSong variation of the South Eastern Indian Ocean pygmy blue whale population in the Perth Canyon, Western Australia0 aSong variation of the South Eastern Indian Ocean pygmy blue whal cOct-01-2020 ae02086190 v143 a

Sea noise collected over 2003 to 2017 from the Perth Canyon, Western Australia was analysed for variation in the South Eastern Indian Ocean pygmy blue whale song structure. The primary song-types were: P3, a three unit phrase (I, II and III) repeated with an inter-song interval (ISI) of 170–194 s; P2, a phrase consisting of only units II & III repeated every 84–96 s; and P1 with a phrase consisting of only unit II repeated every 45–49 s. The different ISI values were approximate multiples of each other within a season. When comparing data from each season, across seasons, the ISI value for each song increased significantly through time (all fits had p << 0.001), at 0.30 s/Year (95%CI 0.217–0.383), 0.8 s/Year (95%CI 0.655–1.025) and 1.73 s/Year (95%CI 1.264–2.196) for the P1, P2 and P3 songs respectively. The proportions of each song-type averaged at 21.5, 24.2 and 56% for P1, P2 and P3 occurrence respectively and these ratios could vary by up to ± 8% (95% CI) amongst years. On some occasions animals changed the P3 ISI to be significantly shorter (120–160 s) or longer (220–280 s). Hybrid song patterns occurred where animals combined multiple phrase types into a repeated song. In recent years whales introduced further complexity by splitting song units. This variability of song-type and proportions implies abundance measure for this whale sub population based on song detection needs to factor in trends in song variability to make data comparable between seasons. Further, such variability in song production by a sub population of pygmy blue whales raises questions as to the stability of the song types that are used to delineate populations. The high level of song variability may be driven by an increasing number of background whale callers creating ‘noise’ and so forcing animals to alter song in order to ‘stand out’ amongst the crowd.

1 aJolliffe, Capri, D.1 aMcCauley, Robert, D.1 aGavrilov, Alexander, N.1 aJenner, Curt, S.1 aJenner, Micheline-Nicole, M.1 aDuncan, Alec, J.1 aMatsumoto, Haru uhttp://dx.plos.org/10.1371/journal.pone.020861903492nas a2200253 4500008004100000022001300041245013000054210006900184260001600253300001400269490000700283520249700290653001802787653002702805653002502832653001902857653003202876100001802908700002202926700001502948700002202963700002002985856023303005 2019 eng d a1470160X00aAn evaluation of the efficiency of passive acoustic monitoring in detecting deer and primates in comparison with camera traps0 aevaluation of the efficiency of passive acoustic monitoring in d cJan-03-2019 a753 - 7620 v983 a

In recent years, camera traps have rapidly become popular for the large-scale monitoring of wildlife distributionand population; however, we should not ignore the uncertainty regarding the reliability of camera-basedmonitoring by inexperienced data gatherers. This study introduces passive acoustic monitoring (PAM) as aneasier technique for monitoring terrestrial mammals that uses the sound cues that they produce. To validate theefficacy of PAM, we quantitatively compared the detection areas and rates between sound cues (from PAM) andvisual cues (from camera traps) of two mammals—the sika deerCervus nipponand the Japanese macaqueMacacafuscata—across seven study sites in eastern Japan with different population densities. To collect sound cues, weset up multiple autonomous recording units at the sites and continuously recorded ambient sounds, following apre-determined schedule. The total recording time reached 9081 h for deer and 8235 h for macaques. We thenbuilt sound recognizers to automatically detect eight target call types from the recorded data. To collect visualcues, we also set multiple camera traps at the same sites and for the same observation periods. The keyfindingswere as follows: (1) the fully automated procedures that only used the recognizers to detect sound cues producednumerous false positive detections when the call type possessed vocal plasticity and variations; (2) the semi-automated procedures, which included an additional step to validate the automated detections by manualscreening, exhibited a great improvement in the detectability and recall rates of the half of the target calls,reaching > 0.70; (3) when using the semi-automated procedures, the frequency of deer and macaque detectionsper trap-day derived from the sound cues were in most cases approximately dozens of times and several times,respectively, higher than that derived from the visual cues; (4) the main advantage of PAM may be its superiordetection areas, which were 100–7000 times wider than those of camera traps; and (5) the current success of therecognition of different call types of each species could broaden the use of PAM, which is not possible for cameratraps. PAM could provide socio-behavioral data (i.e., the frequencies and types of inter-individual vocal com-munications) that could help understand the status of population dynamics and the group compositions, inaddition to information related to the presence or absence of species.

10aCervus nippon10aEcoacoustic monitoring10aLag-phase management10aMacaca fuscata10apassive acoustic monitoring1 aEnari, Hiroto1 aEnari, Haruka, S.1 aOkuda, Kei1 aMaruyama, Tetsuya1 aOkuda, Kana, N. uhttps://linkinghub.elsevier.com/retrieve/pii/S1470160X18309257https://api.elsevier.com/content/article/PII:S1470160X18309257?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S1470160X18309257?httpAccept=text/plain01918nas a2200181 4500008004100000245017100041210006900212260001600281300001100297490000700308520123500315100002101550700001401571700001801585700001901603700001601622856009801638 2019 eng d00aInvestigation on acoustic reception pathways in finless porpoise ( Neophocaena asiaorientalis sunameri ) with insight into an alternative pathway0 aInvestigation on acoustic reception pathways in finless porpoise cJan-01-2019 a0160040 v143 a

Sound transmission and reception are both vital components to odontocete echolocation and daily life. Here, we combine computed tomography (CT) scanning and finite element modeling to investigate the acoustic propagation of finless porpoise (Neophocaena asiaorientalis sunameri) echolocation pulses. The CT scanning and finite element method wave propagation model results support the well-accepted jaw-hearing pathway hypothesis and suggest an additional alternative auditory pathway composed of structures, mandible (lower jaw) and internal mandibular fat, with different acoustic impedances, which may also conduct sounds to the ear complexes. The internal mandibular fat is attached to the ear complex and encased by the mandibles laterally and anteriorly. The simulations show signals in this pathway initially propagate along the solid mandibles and are transmitted to the acoustically coupled soft tissue of the internal mandibular fat which conducts the stimuli posteriorly as it eventually arrives at ear complexes. While supporting traditional theories, this new bone-tissue conduction pathway might be meaningful to understand the hearing and sound reception processes in a wide variety of odontocetes species.

1 aSong, Zhongchang1 aZhang, Yu1 aWang, Xianyan1 aSmith, Adam, B1 aXu, Xiaohui uhttp://stacks.iop.org/1748-3190/14/i=1/a=016004?key=crossref.cd9487fd925bb5ecdc5f0eb7a9bbb813