01979nas a2200157 4500008004100000245014900041210006900190520137800259100002301637700001901660700001701679700002401696700002501720700002201745856005401767 2020 eng d00aMorphological Evidence for the Sensitivity of the Ear Canal of Odontocetes as shown by Immunohistochemistry and Transmission Electron Microscopy0 aMorphological Evidence for the Sensitivity of the Ear Canal of O3 a

Tthe function of the external ear canal in cetaceans is still under debate and its morphology is largely unknown. Immunohistochemical (IHC) analyses using antibodies specific for nervous tissue (anti-S100, anti-NSE, anti-NF, and anti-PGP 9.5), together with transmission electron microscopy (TEM) and various histological techniques, were carried out to investigate the peripheral nervous system of the ear canals of several species of toothed whales and terrestrial cetartiodactyla. this study highlights the innervation of the ear canal with the presence of lamellar corpuscles over its entire course, and their absence in all studied terrestrial mammals. Each corpuscle consisted of a central axon, surrounded by lamellae of Schwann receptor cells, surrounded by a thin cellular layer, as shown by IHC and TEM. These findings indicate that the corpuscles are mechanoreceptors that resemble the inner core of Pacinian corpuscles without capsule or outer core, and were labelled as simple lamellar corpuscles. They form part of a sensory system that may represent a unique phylogenetic feature of cetaceans, and an evolutionary adaptation to life in the marine environment. Although the exact function of the ear canal is not fully clear, we provide essential knowledge and a preliminary hypothetical deviation on its function as a unique sensory organ.

1 aDe Vreese, Steffen1 aAndré, Michel1 aCozzi, Bruno1 aCentelleghe, Cinzia1 avan der Schaar, Mike1 aMazzariol, Sandro uhttp://www.nature.com/articles/s41598-020-61170-401990nas a2200121 4500008004100000245015000041210006900191520148600260100002001746700002401766700002201790856005601812 2020 eng d00aMark recapture distance sampling: using acoustics to estimate the fraction of dolphins missed by observers during shipboard line-transect surveys0 aMark recapture distance sampling using acoustics to estimate the3 a

Cetacean abundance estimation often relies on distance sampling methods using ship-board visual line-transect surveys, which assumes that all animals on the trackline aredetected and that the detection of animals decreases with increasing distance fromthe trackline. Mark–Recapture Distance Sampling (MRDS) typically employs a sec-ondary visual observation team and may be used to identify the fraction of animalsdetected on the trackline when it is suspected that animals may have been missed.For species that are difficult to detect using visual observation methods, such as deep-diving species or those with cryptic surfacing behavior, this secondary team may beprone to the same limitations in detection as the primary observation team and alter-native modes of detection may improve estimates. Here we examine the potential useof passive acoustic detection as a secondary platform for MRDS of rough-tootheddolphins (Steno bredanensis) during a combined visual and acoustic shipboard line-transect survey. The average trackline detection probability for rough-toothed dolphinswas less than one for both the trial configuration (averagep(0)0.45 for the visualteam) and independent observer configuration (averagep(0)0.37 for the visual,p(0)0.77 for the acoustic andp(0)0.84 for both teams combined). This study,while limited in scope, strongly suggests that passive acoustic methods may be aneffective alternative for estimatingp(0)for some cetaceans species.

1 aRankin, Shannon1 aOedekoven, Cornelia1 aArcher, Frederick uhttp://link.springer.com/10.1007/s10651-020-00443-702326nas a2200229 4500008004100000245013900041210006900180520153400249653002301783653003401806653001901840653002401859100001901883700001601902700002601918700001701944700002001961700002401981700001902005700001702024856005502041 2005 eng d00aBottlenose dolphin (Tursiops truncatus) calves appear to model their signature whistles on the signature whistles of community members0 aBottlenose dolphin Tursiops truncatus calves appear to model the3 a

Bottlenose dolphins are unusual among non-human mammals in their ability to learn new sounds. This study investigates the importance of vocal learning in the development of dolphin signature whistles and the influence of social interactions on that process. We used focal animal behavioral follows to observe six calves in Sarasota Bay, Fla., recording their social associations during their first summer, and their signature whistles during their second. The signature whistles of five calves were determined. Using dynamic time warping (DTW) of frequency contours, the calves’ signature whistles were compared to the signature whistles of several sets of dolphins: their own associates, the other calves’ associates, Tampa Bay dolphins, and captive dolphins. Whistles were considered similar if their DTW similarity score was greater than those of 95% of the whistle comparisons. Association was defined primarily in terms of time within 50 m of the mother/calf pair. On average, there were six dolphins with signature whistles similar to the signature whistles of each of the calves. These were significantly more likely to be Sarasota Bay resident dolphins than non-Sarasota dolphins, and (though not significantly) more likely to be dolphins that were within 50 m of the mother and calf less than 5% of the time. These results suggest that calves may model their signature whistles on the signature whistles of members of their community, possibly community members with whom they associate only rarely.

10abottlenose dolphin10aSocial influences on learning10avocal learning10aWhistle development1 aFripp, Deborah1 aOwen, Caryn1 aQuintana-Rizzo, Ester1 aShapiro, Ari1 aBuckstaff, Kara1 aJankowski, Kristine1 aWells, Randall1 aTyack, Peter uhttp://link.springer.com/10.1007/s10071-004-0225-z01130nas a2200145 4500008004100000022001400041245005500055210005500110260001600165300001400181490000700195520071300202100002200915856004700937 2004 eng d a1063-771000aSome results of studying the acoustics of dolphins0 aSome results of studying the acoustics of dolphins cJan-05-2004 a343 - 3490 v503 a

An experimental study of the echolocation ability of dolphins (Tursiops truncatus) is performed in the presence of correlated and uncorrelated broadband noise acting on their organs of hearing. It is shown that, under such conditions, the echolocating pulses of a dolphin become noticeably modified: in the absence of noise, standard broadband pulses are produced, while in the presence of noise, the pulses acquire an oscillatory character (become narrowband). Sounds and air pressure that occur inside the respiratory tract of a dolphin when the animal produces whistles and pulsed signals are studied. Data testifying in favor of the pneumatic origin of sounds generated by dolphins are obtained.

1 aRomanenko, E., V. uhttp://link.springer.com/10.1134/1.173950302151nas a2200145 4500008004100000245008800041210007000129520163300199100002301832700001801855700002001873700002001893700002501913856006701938 2020 eng d00aDolphin whistle repertoires around São Miguel (Azores): Are you common or spotted?0 aDolphin whistle repertoires around São Miguel Azores Are you com3 a

Short-beaked common dolphins (Delphinus delphis) and Atlantic spotted dolphins (Stenella frontalis) are both common in the Azores archipelago during summer. Because both species are sympatric, at least in part of their range, they may use acoustic features to recognize conspecifics and maintain school cohesion throughout their different activities. Delphinid whistles were recorded with a 96-kHz sampling rate using towed hydrophone system during surveys held in summer of 2013 and 2014 around São Miguel Island (Azores, Portugal). A total of 256 whistles attributed to either short-beaked common dolphin (n = 133) or Atlantic spotted dolphin (n = 123) were selected and processed with a contour extraction software. Elementary statistical analysis showed that duration, frequency and slope variables were significantly different for both species, although in most cases their range overlapped. We performed a discriminant analysis to test species classification: the dataset was randomly split into one calibration subset (186 whistles) and one validation subset (70 whistles). The discriminant analysis retained four variables (global slope, duration, minimal and final frequencies) as useful for classification. The discriminant function resulted in correct classification rates of 78.5% (calibration subset) and 81.4% (validation subset). Common dolphin whistles were better classified than Atlantic spotted dolphin whistles (83.4% and 74.8%) respectively. This study shows that reliable species identification can be achieved for common and spotted dolphins using their whistle repertoire characteristics.

1 aGannier, Alexandre1 aFuchs, Sandra1 aGannier, Adrien1 aFernandez, Marc1 aAzevedo, José, M.N. uhttps://linkinghub.elsevier.com/retrieve/pii/S0003682X1630539401972nas 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/s41598-019-51619-602957nas 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.315801589nas 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/10.1007/978-3-030-27947-901898nas 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/5729501971nas a2200193 4500008004100000245010700041210006900148260001600217520132300233100002301556700002301579700002101602700002401623700002001647700002001667700002701687700002001714856004301734 2018 eng d00aWhistle variability of Guiana dolphins in South America: Latitudinal variation or acoustic adaptation?0 aWhistle variability of Guiana dolphins in South America Latitudi cJun-12-20193 a

A previous comparison of whistles using data sampled at 48 kHz suggested that certain frequency parameters vary along a latitudinal gradient. This geographical pattern may be biased because whistles sampled at higher frequencies could potentially have very different frequency contents. The current study compared the acoustic parameters of Guiana dolphin (Sotalia guianensis) whistles recorded at a higher sampling rate (96 kHz) and from groups occupying two never before sampled sites, Benevente Bay, Espírito Santo, Brazil, and Formosa Bay, Rio Grande do Norte, Brazil, with recordings of other populations in South America. By only considering data sampled at a rate of at least 96 kHz, we aimed to detect differences in whistles across locations. Contrary to previous findings, our analyses do not indicate any clear separation between northern and southern populations based on whistles, and do not corroborate the hypothesis of latitudinal acoustic variation in this species. The variation in Guiana dolphin whistle parameters found here appears to be influenced by latitude to some extent, but several other factors, including sampling method, environmental fluctuations, and social influence on vocal learning, may be confounding the detection of a geographic pattern in these whistle samples.

1 aLopes, Nara, Pavan1 aReis, Sarah, Stutz1 aMamede, Natália1 aReis, Suzana, Stutz1 aToledo, Gustavo1 aCorso, Gilberto1 aSousa-lima, Renata, S.1 aAndriolo, Artur uhttp://doi.wiley.com/10.1111/mms.1257201996nas a2200265 4500008004100000022001400041245007900055210006900134260002000203300001300223490000700236520110200243653002701345653002401372653002301396653002301419100001701442700002701459700002201486700001701508700002301525700002001548700001801568856014401586 2018 eng d a1744-956100aDolphins simplify their vocal calls in response to increased ambient noise0 aDolphins simplify their vocal calls in response to increased amb cSep-05-20182022 a201804840 v143 a

Ocean noise varies spatially and temporally and is driven by natural and anthropogenic processes. Increased ambient noise levels can cause signal masking and communication impairment, affecting fitness and recruitment success. However, the effects of increasing ambient noise levels on marine species, such as marine mammals that primarily rely on sound for communication, are not well understood. We investigated the effects of concurrent ambient noise levels on social whistle calls produced by bottlenose dolphins (Tursiops truncatus) in the western North Atlantic. Elevated ambient noise levels were mainly caused by ship noise. Increases in ship noise, both within and below the dolphins' call bandwidth, resulted in higher dolphin whistle frequencies and a reduction in whistle contour complexity, an acoustic feature associated with individual identification. Consequently, the noise-induced simplification of dolphin whistles may reduce the information content in these acoustic signals and decrease effective communication, parent–offspring proximity or group cohesion.

10aacoustic communication10aanthropogenic noise10abottlenose dolphin10avocal modification1 aFouda, Leila1 aWingfield, Jessica, E.1 aFandel, Amber, D.1 aGarrod, Aran1 aHodge, Kristin, B.1 aRice, Aaron, N.1 aBailey, Helen uhttp://rsbl.royalsocietypublishing.org/lookup/doi/10.1098/rsbl.2018.0484https://syndication.highwire.org/content/doi/10.1098/rsbl.2018.048401996nas a2200181 4500008004100000022001400041245016200055210006900217260001600286300001600302490000800318520134700326100001801673700002401691700002401715700002401739856005101763 2018 eng d a0001-496600aForward masking recovery in bottlenose dolphins ( Tursiops truncatus): Auditory brainstem responses to paired-click stimuli in high-pass masking noise0 aForward masking recovery in bottlenose dolphins iTursiops trunca cJan-09-2018 a1740 - 17400 v1443 a

Adaptation is a fundamental process in the auditory system and underlies the automatic gain control system of echolocating bottlenose dolphins. As pulse-echo delay increases, auditory brainstem response (ABR) amplitudes to the echoes progressively increase. This study examined adaptation across cochlear frequency regions using a paired-click (i.e., forward masking) paradigm and high-pass masking noise. Bottlenose dolphins passively listened to paired click stimuli (20–160 kHz “pink” spectra). A “conditioning” click was followed by a “probe” click with equal amplitude and a time delay ranging from 125 to 750 μs. ABRs to click pairs were obtained with and without high-pass masking noise that precluded the basal turn of the cochlea from responding to the click stimuli. The ABR evoked by a single click (temporally aligned with the first click of the paired-click condition) was subtracted from the click-pair ABR to visualize the response evoked by the probe click. Probe ABR amplitudes recovered linearly with increasing delay relative to the conditioning click, and were approximately 70% of full response amplitude at 750-μs delay. Paired-click interval ABR amplitude recovery functions were similar for the unmasked and high-pass masked conditions. [Work sponsored by ONR.]

1 aMulsow, Jason1 aCoffinger, Sean, P.1 aFinneran, James, J.1 aBurkard, Robert, F. uhttp://asa.scitation.org/doi/10.1121/1.506771801900nas a2200193 4500008004100000022001400041245008000055210006900135260001600204300001600220490000800236520131000244100001901554700002101573700001901594700002301613700001901636856005101655 2018 eng d a0001-496600aTowards the topology of autoencoder of calls versus clicks of marine mammal0 aTowards the topology of autoencoder of calls versus clicks of ma cJan-09-2018 a1777 - 17780 v1443 a

The goal is to learn the features and the representation adapted for cetacean sound dynamics without any priors. Thus, we develop data driven model to generate voicing and click of cetaceans audio signals. We learn representation and features of stationary or nonstationary emission using neural network from raw audio. We use different types of convolutions (causal, with strides, with dilation [1]), or gradient inversion [2]. Experiments are conducted on various kind of calls of humpback whales from nips4b challenge [3] or Orca whale. We compare the topology for transient encoding on Physeters and Inia g. For each model, we detail the resulting filters and discuss on the topology. We acknowledge Region PACA and NortekMED for Roger’s Phd grant, & DGA and Région Haut de France for Ferrari’s Phd grant. [1] Oord, Dieleman, Zen, Simonyan, Vinyals, Graves et al. Wavenet : A generative model for raw audio, arXiv:1609.03499, 2016 [2] Balestriero, Roger, Glotin, Baraniuk, Semi-Supervised Learning via New Deep Network Inversion, arXiv:1711.04313, 2017 [3] Glotin, LeCun, Mallat et al. Proc. 1st wkp on Neural Information Processing for Bioacoustics NIPS4B, joint to NIPS Alberta USA, 2013 http://sabiod.org/nips4b/challenge2.html, http://sabiod.org/NIPS4B2013_book.pdf

1 aRoger, Vincent1 aFerrari, Maxence1 aMarxer, Ricard1 aChamroukhi, Faicel1 aGlotin, Hervé uhttp://asa.scitation.org/doi/10.1121/1.506785901844nas a2200193 4500008004100000022001400041245011000055210006900165260001600234300001600250490000800266520121600274100002101490700001801511700001801529700002501547700002701572856005101599 2018 eng d a0001-496600aMonitoring noise levels and delphinid presence through autonomous acoustic in Rio de Janeiro coastal area0 aMonitoring noise levels and delphinid presence through autonomou cJan-09-2018 a1885 - 18850 v1443 a

In order to investigate the soundscape in a Rio de Janeiro coast site, passive acoustic monitoring was conducted during two non-consecutive weeks in the summer of 2015/2016 by deploying one SM2M + device. The equipment recorded at a 66% duty cycle with sample rate of 96 kHz and 36 dB gain. Third octave levels (TOLs) were calculated for all recordings through PAMGuide software. To search for delphinid presence, a band limited energy detector was employed using Raven 1.5 in a 512 Hann window, 50% overlap. TOLs varied across frequencies and day hours. Light hours were noisier than dark hours in 25 frequency bands (MW, p<0.01), with highest mean level being measured at 794 Hz at 06am (105.4 ± 5.4 dB re 1μPa), and lowest mean level measured at 39.8 kHz at 01am (80.3 ± 3.7 dB re 1μPa). A total of 281 delphinid sound emissions were detected in nine occasions, seven during week 1 and two during week 2. Seven detection events occurred during dark hours. Although more than one species of delphinid is known to occur in Rio de Janeiro coast, these results indicate a frequent nocturnal use of the area, which was only possible to observe through autonomous monitoring.

1 aBittencourt, Lis1 aSousa, André1 aBisi, Tatiana1 aLailson-Brito, José1 aAzevedo, Alexandre, d. uhttp://asa.scitation.org/doi/10.1121/1.506826402022nas a2200193 4500008004100000022001400041245012000055210006900175260001600244300001600260490000800276520139100284100001901675700001801694700002601712700002401738700001501762856005101777 2018 eng d a0001-496600aBottlenose dolphin ( Tursiops truncatus) vocal modifications in response to spectrally pink background noise0 aBottlenose dolphin iTursiops truncatusi vocal modifications in r cJan-09-2018 a1742 - 17420 v1443 a

The increase of oceanic shipping is a global predicament. The resulting proliferation of underwater noise levels is a serious concern for marine mammal welfare, as it has the potential to interfere with the communicative signals of bottlenose dolphins (Tursiops truncatus). The Lombard effect and other noise-induced vocal modifications may be employed to compensate for reduced signal-to-noise ratios. This study aimed to determine which vocal modifications dolphins use during experimentally controlled background noise conditions. Three dolphins (ages 30–52) participated in behavioral hearing tests using an adaptive up-down staircase, go/no-go procedure with 15 or 40 kHz tones. Tones decreased by 3 dB increments if a dolphin responded to the tone with a conditioned whistle, and increased by 3 dB if they did not. Dolphins performed this task during ambient noise (control) conditions, as well as three elevated bandpass noise (experimental) conditions: 0.6–5 kHz (115 dB re 1 μPa) and 0.6–10 kHz (115 and 125 dB re 1 μPa). The acoustic parameters of the dolphins’ response whistles and victory squeals, such as duration, frequency, amplitude, and response latency, were analyzed and compared between control and noise conditions. These data provide a complement to field studies of odontocete noise-induced vocal modifications in the wild.

1 aZapetis, Maria1 aMulsow, Jason1 aSchlundt, Carolyn, E.1 aFinneran, James, J.1 aLyn, Heidi uhttp://asa.scitation.org/doi/10.1121/1.506772402032nas a2200205 4500008004100000022001400041245016300055210006900218260001600287300001600303490000800319520131500327100002101642700002101663700002101684700001801705700002501723700002701748856005101775 2018 eng d a0001-496600aCharacteristics of Guiana dolphins ( Sotalia guianensis) burst-pulse sounds emitted during different surface activity rates in Rio de Janeiro’s coast0 aCharacteristics of Guiana dolphins iSotalia guianensisi burstpul cJan-09-2018 a1978 - 19780 v1443 a

Burst-pulses are still the least studied signals in delphinid acoustic repertoire. In this study, acoustic data were gathered in two Rio de Janeiro coastal bays where groups of Guiana dolphins can be found regularly. The acoustic equipment consisted of a C54XRS hydrophone (-155.8 dBV, 0.006 Hz a 203 kHz) and a Fostex digital recorder (192 kHz sampling rate). During each recording, the surface activity rate of the group was classified as being high or low. Burst-pulses were analyzed using SoundRuler software. Fifty signals were randomly selected and the values for duration (low = 143.9 ± 145.4; high = 82.2 ± 74.8), interpulse interval (low = 2.81 ± 1.92; high = 1.34 ± 1.35), number of pulses (low = 52.6 ± 55.7; high = 71.6 ± 64.5), peak frequency (low = 37.4 ± 2.5; high = 38.5 ± 3.2), and minimum frequency (low = 15.4 ± 6.5; high = 6.7 ± 5.3) were measured. Additionally, a Mann-Whitney U test compared all acoustic parameters of burst-pulses emitted during both surface activity rates. Significant differences between activity rates were found for interpulse interval (p<0.01) and minimum frequency (p<0.01). This scenario could indicate that some burst-pulse parameters are related to group arousal and behavior.

1 aBarbosa, Mariana1 aBittencourt, Lis1 aAndrade, Luciana1 aBisi, Tatiana1 aLailson-Brito, José1 aAzevedo, Alexandre, d. uhttp://asa.scitation.org/doi/10.1121/1.506863601989nas a2200181 4500008004100000022001400041245010200055210006900157260001600226300001600242490000800258520140900266100002101675700001901696700002101715700002001736856005101756 2018 eng d a0001-496600aAntarctic type C killer whale ( Orcinus orca) call repertoire from McMurdo Sound, Ross Sea0 aAntarctic type C killer whale iOrcinus orcai call repertoire fro cJan-09-2018 a1978 - 19780 v1443 a

Killer whales (Orcinus orca) are found in all oceans of the world. In Antarctic waters, five ecotypes have been described, each displaying distinct differences in morphological features, foraging behaviours, habitat and diet preferences, and genetic structure. Acoustic recordings of Type C killer whales were collected between December 2012 and January 2013 in McMurdo Sound, Ross Sea, Antarctica. Spectrograms of acoustic data were examined for characteristic patterns of Type C vocalizations and a call type catalogue was produced. We measured acoustic parameters of each call type for both whistle and burst-pulse sounds and we then compared call features of Type C animals to those of other killer whales described in the Southern Hemisphere. Analysis of calls revealed that Type C killer whales produce a large number of biphonations and complex calls with multiple frequency-modulated and pulsed components. The limited accessibility of Antarctic regions year-round makes passive acoustic monitoring (PAM) a very effective tool to derive information on ecotype-specific distribution and seasonal occurrence. This study provides new information on the call repertoire of Type C killer whales, investigates the potential use of PAM to study Antarctic ecotypes, and also examines utilising call repertoire as a reliable diagnostic tool for identifying sympatric ecotypes in Antarctic waters.

1 aWellard, Rebecca1 aPitman, Robert1 aDurban, John, W.1 aErbe, Christine uhttp://asa.scitation.org/doi/10.1121/1.506863502088nas a2200193 4500008004100000022001400041245008800055210006900143260001600212300001600228490000800244520146800252100002301720700002801743700002901771700002301800700002001823856005101843 2018 eng d a0001-496600aClymene dolphin ( Stenella clymene) whistles in the Southwest Atlantic Ocean0 aClymene dolphin iStenella clymenei whistles in the Southwest Atl cJan-09-2018 a1952 - 19520 v1443 a

The Clymene dolphin despite being endemic for the Atlantic Ocean continues to be the least known species in the genus Stenella without available information on their vocal repertoire in Brazilian waters. Data were obtained during mitigation and monitoring work required by IBAMA under the federal environmental licensing as conditions of the license 108/16 for the 3D seismic survey in Pará/Maranhão Sedimentary Basin process 02022.000015/2014. The species record was performed onboard the vessel Polarcus Alima with a Mseis (Night Hawk III) four-element towed array passing signals to a digital M-Audio, recording at 96 kHz/16bits. During visual and acoustic monitoring with the air-guns off, a group of approximate 80 dolphins were sighted and recorded on May 8th, 2016 (00˚38’00” N, 44˚45’25” O) at 3,425 m depth. The wav-files were analyzed through the spectrogram configured as DFT 2048 samples, 70% overlap and Hamming window of 1024 points generated by software Raven Pro 1.5. The results of 14 min recording allowed the extraction of 257 whistles. Minimum frequencies ranged from 5.20 kHz to 15.92 kHz (mean = 10.99 kHz); maximum frequencies ranged from 7.72 kHz to 28.04 kHz (mean = 16.16 kHz); whistle duration ranged from 0.01 s to 1.52 s (mean = 0.43 s). These results are important since they represent the first acoustic record of Clymene dolphins in Brazil.

1 aMoron, Juliana, R.1 aAlves, Luiz, Cláudio P1 ade Assis, Carla, Viviane1 aGarcia, Felipe, C.1 aAndriolo, Artur uhttp://asa.scitation.org/doi/10.1121/1.506853401960nas a2200181 4500008004100000022001400041245015000055210006900205260001600274300001600290490000800306520132700314100002001641700002401661700001801685700002401703856005101727 2018 eng d a0001-496600aDependence of bottlenose dolphin (Tursiops truncatus) auditory brainstem responses on noise burst rise time, amplitude, and envelope shape0 aDependence of bottlenose dolphin iTursiops truncatusi auditory b cJan-09-2018 a1741 - 17410 v1443 a

A series of experiments examined the dependence of dolphin auditory brainstem response (ABR) peak amplitudes and latencies by stimulus level, rise times, and envelope shape. Stimuli were spectrally “pink” noise bursts with frequency content from 10 to 160 kHz, rise times that varied from 32 μs to 4 ms, and plateau sound pressure levels from 102 to 138 dB re 1 μPa. Cosine and cosine-cubed rise (and fall) envelopes were tested, and results were compared to those obtained for dolphins using noise bursts with linear rise envelopes [Finneran et al., J. Acoust. Soc. Am. 143, 2914–2921 (2018)]. Results for the cosine and cosine-cubed envelopes showed that ABR peak amplitudes were a function of envelope sound pressure at the end of a fixed integration window of approximately 260 μs. This is congruent with the previous findings for linear envelopes. The ABR peak latencies for the cosine and cosine-cubed envelopes were dependent on the second derivative of the envelope pressure function, as opposed to the first derivative of the pressure function for linear envelopes. These data are consistent with single-unit and nearfield response data for terrestrial mammals. [Work supported by Navy Living Marine Resources and SSC Pacific Naval Innovative Science and Engineering Programs.]

1 aJones, Ryan, A.1 aFinneran, James, J.1 aMulsow, Jason1 aBurkard, Robert, F. uhttp://asa.scitation.org/doi/10.1121/1.506772201795nas a2200181 4500008004100000022001400041245008300055210006900138260001600207300001600223490000800239520123900247100001701486700002101503700002101524700001701545856005101562 2018 eng d a0001-496600aSoundscape characteristics in Southern Resident Killer Whale critical habitats0 aSoundscape characteristics in Southern Resident Killer Whale cri cJan-09-2018 a1846 - 18460 v1443 a

The Southern Resident Killer whales (Orcinus orca) (SRKW) are an endangered group of orcas with current range of Pacific North East from California to Northern British Columbia and spend most of the summer months in and around the Salish Sea. This group of mammals feed primarily on fish, are very local, and live in tight-knit family units called pods. July 1 2017 census reported 77 animals; which now has been reduced to 76 by a more recent death. Anthropogenic underwater noise, primarily from commercial and recreational vessels is suspected to have detrimental effects on these whales. Here, we present results from a seven month, continuous sound recording (125 kHz acoustic bandwidth), whale centered study to monitor and interpret different soundscapes in SRKW critical habitats. The six different locations studied have significantly different acoustic transmission characteristics and cover open ocean areas, where natural sound spectral levels are high, to areas where anthropogenic noise-sources dominate. Possible implications of these different characteristics on the ability of the orcas to communicate and find prey are discussed. [Work funded by the Ocean Protection Plan (OPP) of the Government of Canada.]

1 aVagle, Svein1 aO'Neill, Caitlin1 aThornton, Sheila1 aYurk, Harald uhttp://asa.scitation.org/doi/10.1121/1.506813002099nas a2200181 4500008004100000022001400041245006900055210006900124260001600193300001600209490000800225520154400233100002401777700002301801700002401824700001801848856005101866 2018 eng d a0001-496600aPassive echo detection and discrimination in bottlenose dolphins0 aPassive echo detection and discrimination in bottlenose dolphins cJan-09-2018 a1741 - 17410 v1443 a

Echolocation in bottlenose dolphins (Tursiops truncatus) is an active process involving outgoing signal transmission and echo reception. Transmitted echolocation “clicks” interact with a target to produce echoes that contain representative information about the target. Echolocation allows dolphins to detect, discriminate, and identify complex targets using only their hearing. However, it is unclear whether dolphins capitalize on an internal representation of echolocation clicks for matched filter processing or whether the same information (and performance) can be obtained through passive echo reception (i.e., without a corresponding ensonifying click). Here, we investigate the passive echo discrimination ability of a bottlenose dolphin by embedding a target echo in a stream of distractor echoes with similar spectral and time-domain characteristics. Initial testing has demonstrated excellent echo-discrimination ability in the light of multiple distractor echoes of similar amplitude. Additional testing is underway with expanded distractor sets and echo-ordering complexity. The paradigm specifically investigates the plausibility of perceptual identification without the potential for matched filter processing. If representational identity is attainable via a passive process and not degraded relative to active echolocation, then the function of the echolocation click might not serve in matched filter processing, though it would remain important for ensonification and in determining target location.

1 aCoffinger, Sean, P.1 aHouser, Dorian, S.1 aFinneran, James, J.1 aMulsow, Jason uhttp://asa.scitation.org/doi/10.1121/1.506772101622nas a2200193 4500008004100000022001400041245011200055210007100167260001600238300001600254490000800270520098500278100002601263700001801289700002701307700002401334700001901358856005101377 2018 eng d a0001-496600aDirectional hearing sensitivity for 2–30 kHz sounds in the bottlenose dolphin (Tursiops truncatus)0 aDirectional hearing sensitivity for 2–30 kHz sounds in the bottl cJan-09-2018 a1741 - 17410 v1443 a

Bottlenose dolphins (Tursiops truncatus) depend on sounds with frequencies <30 kHz for social communication and foraging, but little information on the directional dependence of hearing thresholds for these sounds exists. This study measured behavioral hearing thresholds for 2, 10, 20, and 30-kHz tones projected from eight different angular positions around the dolphin in both the horizontal and vertical planes to determine whether the receiving beam at these frequencies was directional. Omni-directional hearing was hypothesized for sounds below 30 kHz, but this hypothesis was rejected. Results from two bottlenose dolphins demonstrated a positive relationship between directivity and the frequency of the test tone, with asymmetric beam patterns. Directional hearing sensitivity declined most dramatically between 10 kHz and 2 kHz. The results suggest that dolphins’ directional hearing is more pronounced for lower frequencies than previously predicted.

1 aAccomando, Alyssa, W.1 aMulsow, Jason1 aBranstetter, Brian, K.1 aFinneran, James, J.1 aJenkins, Keith uhttp://asa.scitation.org/doi/10.1121/1.506772002101nas a2200193 4500008004100000022001400041245014100055210006900196260001600265300001600281490000800297520144900305100002201754700002001776700002101796700002201817700001701839856005101856 2018 eng d a0001-496600aBone-conducted sound in a dolphin's mandible: Experimental investigation of elastic waves mediating information on sound source position0 aBoneconducted sound in a dolphins mandible Experimental investig cJan-10-2018 a2213 - 22240 v1443 a

Mammals use binaural or monaural (spectral) cues to localize acoustic sources. While the sensitivity of terrestrial mammals to changes in source elevation is relatively poor, the accuracy achieved by the odontocete cetaceans' biosonar is high, independently of where the source is. Binaural/spectral cues are unlikely to account for this remarkable skill. In this paper, bone-conducted sound in a dolphin's mandible is studied, investigating its possible contribution to sound localization. Experiments are conducted in a water tank by deploying, on the horizontal and median planes of the skull, ultrasound sources that emit synthetic clicks between 45 and 55 kHz. Elastic waves propagating through the mandible are measured at the pan bones and used to localize source positions via either binaural cues or a correlation-based full-waveform algorithm. Exploiting the full waveforms and, most importantly, reverberated coda, it is possible to enhance the accuracy of source localization in the vertical plane and achieve similar resolution of horizontal- vs vertical-plane sources. The results noted in this paper need to be substantiated by further experimental work, accounting for soft tissues and making sure that the data are correctly mediated to the internal ear. If confirmed, the results would favor the idea that dolphin's echolocation skills rely on the capability to analyze the coda of biosonar echoes.

1 aReinwald, Michael1 aGrimal, Quentin1 aMarchal, Jacques1 aCatheline, Stefan1 aBoschi, Lapo uhttp://asa.scitation.org/doi/10.1121/1.506335602236nas a2200253 4500008004100000245017200041210006900213260001600282300001400298490000700312520141300319653002101732653001001753653003201763653001801795653001301813100002101826700002001847700001601867700001501883700002201898700001901920856004301939 2018 eng d00aDescription and classification of Indian Ocean humpback dolphin ( Sousa plumbea ) whistles recorded off the Sindhudurg coast of Maharashtra, India0 aDescription and classification of Indian Ocean humpback dolphin  cJan-07-2018 a755 - 7760 v343 a

The Indian Ocean humpback dolphin (Sousa plumbea), a common cetacean species in India, has a diverse vocal repertoire, which to date has not been described in detail. This study focused on analyzing their whistle vocalizations. Humpback dolphins were recorded off the Sindhudurg coast of Maharashtra, India, and 2,260 whistles were analyzed for their acoustic characteristics. Whistles spanned a wide frequency range between 2.3 kHz and 33.0 kHz, with durations ranging from 0.01 s to 1.60 s. Whistles were categorized into seven contour classes based on their qualitative prop- erties. A classification and regression tree (CART) analysis was used to quantify vari- ability between the seven contour classes using the measured acoustic features. Based on the CART analysis, frequency gradient, minimum slope, maximum slope, begin- ning and ending slope accounted for most variability between whistle types. CART resulted in an overall classification accuracy of 89.5%. This study provides a detailed description of acoustic features and qualitative properties of humpback dolphin whis- tles from the northwestern coast of India. Further comparisons of acoustic data from Sousa populations along the Indian coast are necessary to determine possible geo- graphic variations in whistle characteristics and whether the variations are driven by environmental or genetic factors or a combination of both.

10ahumpback dolphin10aIndia10apassive acoustic monitoring10aSousa plumbea10awhistles1 aBopardikar, Isha1 aSutaria, Dipani1 aSule, Mihir1 aJog, Ketki1 aPatankar, Vardhan1 aKlinck, Holger uhttp://doi.wiley.com/10.1111/mms.v34.302500nas a2200193 4500008004100000245008100041210006900122260001600191300001400207490000800221520188400229100001802113700002102131700002202152700002902174700002802203700002002231856005502251 2017 eng d00aBottlenose dolphins that forage with artisanal fishermen whistle differently0 aBottlenose dolphins that forage with artisanal fishermen whistle cJan-12-2017 a906 - 9150 v1233 a

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

1 aRomeu, Bianca1 aCantor, Mauricio1 aBezamat, Carolina1 aSimões-Lopes, Paulo, C.1 aDaura-Jorge, Fábio, G.1 aEbensperger, L. uhttp://doi.wiley.com/10.1111/eth.2017.123.issue-1200485nas a2200121 4500008004100000245013000041210006900171260001600240100002100256700002200277700002100299856004300320 2016 eng d00aSuccessful suction-cup tagging of a small delphinid species, Stenella attenuata: Insights into whistle characteristics0 aSuccessful suctioncup tagging of a small delphinid species iSten cJan-12-20161 aSilva, Tammy, L.1 aSayigh, Laela, S.1 aBaird, Robin, W. uhttp://doi.wiley.com/10.1111/mms.1237602101nas a2200265 4500008004100000245012000041210006900161260001600230520128800246653001401534653001701548653001901565653001501584653001301599653002401612653001301636100002001649700002201669700002601691700002201717700002001739700001701759700001601776856004301792 2016 eng d00aAcoustic classification of dolphins in the California Current using whistles, echolocation clicks, and burst pulses0 aAcoustic classification of dolphins in the California Current us cJan-12-20163 a

Passive acoustic monitoring of dolphins is limited by our ability to classify calls to species. Significant overlap in call characteristics among many species, combined with a wide range of call types and acoustic behavior, makes classification of calls to species challenging. Here, we introduce BANTER, a compound acoustic classification method for dolphins that utilizes information from all call types produced by dolphins rather than a single call type, as has been typical for acoustic classifiers. Output from the passive acoustic monitoring software, PAMGuard, was used to create independent classifiers for whistles, echolocation clicks, and burst pulses, which were then merged into a final, compound classifier for each species. Classifiers for five species found in the California Current ecosystem were trained and tested using 153 single-species acoustic events recorded during a 4.5 mo combined visual and acoustic shipboard cetacean survey off the west coast of the United States. Correct classification scores for individual species ranged from 71% to 92%, with an overall correct classification score of 84% for all five species. The conceptual framework of this approach easily lends itself to other species and study areas as well as to noncetacean taxa.

10aacoustics10aburst pulses10aclassification10adelphinids10adolphins10aecholocation clicks10awhistles1 aRankin, Shannon1 aArcher, Frederick1 aKeating, Jennifer, L.1 aOswald, Julie, N.1 aOswald, Michael1 aCurtis, Alex1 aBarlow, Jay uhttp://doi.wiley.com/10.1111/mms.1238100578nas a2200157 4500008004100000245011600041210006900157260001600226300001200242490000700254100002800261700002300289700002500312700003000337856005300367 2017 eng d00aDifferent modes of acoustic communication in deep-diving short-finned pilot whales (Globicephala macrorhynchus)0 aDifferent modes of acoustic communication in deepdiving shortfin cJan-01-2017 a59 - 790 v331 aPérez, Jacobo, Marrero1 aJensen, Frants, H.1 aRojano-Doñate, Laia1 ade Soto, Natacha, Aguilar uhttp://doi.wiley.com/10.1111/mms.2017.33.issue-1