@article {58409, title = {Morphological Evidence for the Sensitivity of the Ear Canal of Odontocetes as shown by Immunohistochemistry and Transmission Electron Microscopy}, year = {2020}, abstract = {

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.

}, doi = {10.1038/s41598-020-61170-4}, url = {http://www.nature.com/articles/s41598-020-61170-4}, author = {De Vreese, Steffen and Andr{\'e}, Michel and Cozzi, Bruno and Centelleghe, Cinzia and van der Schaar, Mike and Mazzariol, Sandro} } @article {58310, title = {Mark recapture distance sampling: using acoustics to estimate the fraction of dolphins missed by observers during shipboard line-transect surveys}, year = {2020}, abstract = {

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.

}, doi = {10.1007/s10651-020-00443-7}, url = {http://link.springer.com/10.1007/s10651-020-00443-7}, author = {Rankin, Shannon and Oedekoven, Cornelia and Archer, Frederick} } @article {58230, title = {Bottlenose dolphin (Tursiops truncatus) calves appear to model their signature whistles on the signature whistles of community members}, year = {2005}, abstract = {

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.

}, keywords = {bottlenose dolphin, Social influences on learning, vocal learning, Whistle development}, doi = {10.1007/s10071-004-0225-z}, url = {http://link.springer.com/10.1007/s10071-004-0225-z}, author = {Fripp, Deborah and Owen, Caryn and Quintana-Rizzo, Ester and Shapiro, Ari and Buckstaff, Kara and Jankowski, Kristine and Wells, Randall and Tyack, Peter} } @article {58228, title = {Some results of studying the acoustics of dolphins}, journal = {Acoustical Physics}, volume = {50}, year = {2004}, month = {Jan-05-2004}, pages = {343 - 349}, abstract = {

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.

}, issn = {1063-7710}, doi = {10.1134/1.1739503}, url = {http://link.springer.com/10.1134/1.1739503}, author = {Romanenko, E. V.} } @article {57998, title = {Dolphin whistle repertoires around S{\~a}o Miguel (Azores): Are you common or spotted?}, year = {2020}, abstract = {

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 S\ão 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.

}, doi = {10.1016/j.apacoust.2019.107169}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0003682X16305394}, author = {Gannier, Alexandre and Fuchs, Sandra and Gannier, Adrien and Fernandez, Marc and Azevedo, Jos{\'e} M.N.} } @article {57917, title = {Sounds associated with foraging and prey capture in individual fish-eating killer whales, Orcinus orca}, year = {2019}, abstract = {

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.

}, doi = {10.1121/1.5133388}, url = {http://asa.scitation.org/doi/10.1121/1.5133388}, author = {Marla M. Holt and Hanson, M. Bradley and Emmons, Candice K. and Haas, David K. and Giles, Deborah A. and Hogan, Jeffrey T.} } @article {57639, title = {Deep-diving pilot whales make cheap, but powerful, echolocation clicks with 50 {\textmu}L of air}, year = {2019}, abstract = {

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.

}, doi = {10.1038/s41598-019-51619-6}, url = {http://www.nature.com/articles/s41598-019-51619-6}, author = {Foskolos, Ilias and Aguilar de Soto, Natacha and Peter Teglberg Madsen and Johnson, Mark} } @article {57614, title = {The 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 Sea}, year = {2019}, abstract = {

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.

}, doi = {10.1002/aqc.3158}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aqc.3158}, author = {Papale, Elena and Alonge, Giuseppe and Caruso, Francesco and Grammauta, Rosario and Mazzola, Salvatore and Mussi, Barbara and Pace, Daniela and Buscaino, Giuseppa} } @article {57409, title = {Acoustic recordings of rough-toothed dolphin ( Steno bredanensis) offshore Eastern Sicily (Mediterranean Sea)}, journal = {The Journal of the Acoustical Society of America}, volume = {146}, year = {2019}, month = {Jan-09-2019}, pages = {EL286 - EL292}, abstract = {

Rough-toothed dolphin\&$\#$39;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.

}, issn = {0001-4966}, doi = {10.1121/1.5126118}, url = {http://asa.scitation.org/doi/10.1121/1.5126118}, author = {Caruso, Francesco and Sciacca, Virginia and Parisi, Ignazio and Viola, Salvatore and de Vincenzi, Giovanni and Bocconcelli, Alessandro and Mooney, T. Aran and Li, Songhai and Filiciotto, Francesco and Moulins, Aurelie and Tepsich, Paola and Rosso, Massimiliano} } @book {57373, title = {Deep Representation Learning for Orca Call Type Classification}, year = {2019}, abstract = {

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.

}, keywords = {bioacoustics, call type, classification, Deep learning, Killer whale, Orca, Representation learning}, isbn = {978-3-030-27946-2}, doi = {10.1007/978-3-030-27947-910.1007/978-3-030-27947-9_23}, url = {http://link.springer.com/10.1007/978-3-030-27947-9}, author = {Bergler, Christian and Schmitt, Manuel and Cheng, Rachael Xi and Schr{\"o}ter, Hendrik and Maier, Andreas and Barth, Volker and Weber, Michael and N{\"o}th, Elmar}, editor = {Ek{\v s}tein, Kamil} } @mastersthesis {57295, title = {Vocal Response of Bottlenose Dolphins (Tursiops truncatus) to a Novel Stimulus}, volume = {MA}, year = {2019}, school = {University of Southern Mississippi}, abstract = {

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.

}, author = {Johnson, Lindsey} } @article {53443, title = {Whistle variability of Guiana dolphins in South America: Latitudinal variation or acoustic adaptation?}, journal = {Marine Mammal Science}, year = {2018}, month = {Jun-12-2019}, abstract = {

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, Esp\írito 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.

}, doi = {10.1111/mms.12572}, url = {http://doi.wiley.com/10.1111/mms.12572}, author = {Lopes, Nara Pavan and Reis, Sarah Stutz and Mamede, Nat{\'a}lia and Reis, Suzana Stutz and Toledo, Gustavo and Corso, Gilberto and Sousa-lima, Renata S. and Andriolo, Artur} } @article {53324, title = {Dolphins simplify their vocal calls in response to increased ambient noise}, journal = {Biology Letters}, volume = {14}, year = {2018}, month = {Sep-05-20182022}, pages = {20180484}, abstract = {

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\&$\#$39; 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.

}, keywords = {acoustic communication, anthropogenic noise, bottlenose dolphin, vocal modification}, issn = {1744-9561}, doi = {10.1098/rsbl.2018.0484}, url = {http://rsbl.royalsocietypublishing.org/lookup/doi/10.1098/rsbl.2018.0484https://syndication.highwire.org/content/doi/10.1098/rsbl.2018.0484}, author = {Fouda, Leila and Wingfield, Jessica E. and Fandel, Amber D. and Garrod, Aran and Hodge, Kristin B. and Rice, Aaron N. and Bailey, Helen} } @article {53317, title = {Forward masking recovery in bottlenose dolphins ( Tursiops truncatus): Auditory brainstem responses to paired-click stimuli in high-pass masking noise}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-09-2018}, pages = {1740 - 1740}, abstract = {

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.]

}, issn = {0001-4966}, doi = {10.1121/1.5067718}, url = {http://asa.scitation.org/doi/10.1121/1.5067718}, author = {Mulsow, Jason and Coffinger, Sean P. and Finneran, James J. and Burkard, Robert F.} } @article {53310, title = {Towards the topology of autoencoder of calls versus clicks of marine mammal}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-09-2018}, pages = {1777 - 1778}, abstract = {

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 R\égion 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

}, issn = {0001-4966}, doi = {10.1121/1.5067859}, url = {http://asa.scitation.org/doi/10.1121/1.5067859}, author = {Roger, Vincent and Ferrari, Maxence and Marxer, Ricard and Chamroukhi, Faicel and Glotin, Herv{\'e}} } @article {53309, title = {Monitoring noise levels and delphinid presence through autonomous acoustic in Rio de Janeiro coastal area}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-09-2018}, pages = {1885 - 1885}, abstract = {

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 1\μPa), and lowest mean level measured at 39.8 kHz at 01am (80.3 \± 3.7 dB re 1\μPa). 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.

}, issn = {0001-4966}, doi = {10.1121/1.5068264}, url = {http://asa.scitation.org/doi/10.1121/1.5068264}, author = {Bittencourt, Lis and Sousa, Andr{\'e} and Bisi, Tatiana and Lailson-Brito, Jos{\'e} and Azevedo, Alexandre d.} } @article {53292, title = {Bottlenose dolphin ( Tursiops truncatus) vocal modifications in response to spectrally pink background noise}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-09-2018}, pages = {1742 - 1742}, abstract = {

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.

}, issn = {0001-4966}, doi = {10.1121/1.5067724}, url = {http://asa.scitation.org/doi/10.1121/1.5067724}, author = {Zapetis, Maria and Mulsow, Jason and Schlundt, Carolyn E. and Finneran, James J. and Lyn, Heidi} } @article {53291, title = {Characteristics of Guiana dolphins ( Sotalia guianensis) burst-pulse sounds emitted during different surface activity rates in Rio de Janeiro{\textquoteright}s coast}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-09-2018}, pages = {1978 - 1978}, abstract = {

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.

}, issn = {0001-4966}, doi = {10.1121/1.5068636}, url = {http://asa.scitation.org/doi/10.1121/1.5068636}, author = {Barbosa, Mariana and Bittencourt, Lis and Andrade, Luciana and Bisi, Tatiana and Lailson-Brito, Jos{\'e} and Azevedo, Alexandre d.} } @article {53290, title = {Antarctic type C killer whale ( Orcinus orca) call repertoire from McMurdo Sound, Ross Sea}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-09-2018}, pages = {1978 - 1978}, abstract = {

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.

}, issn = {0001-4966}, doi = {10.1121/1.5068635}, url = {http://asa.scitation.org/doi/10.1121/1.5068635}, author = {Wellard, Rebecca and Pitman, Robert and John W. Durban and Erbe, Christine} } @article {53288, title = {Clymene dolphin ( Stenella clymene) whistles in the Southwest Atlantic Ocean}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-09-2018}, pages = {1952 - 1952}, abstract = {

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 Par\á/Maranh\ão 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 (00o38\’00\” N, 44o45\’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.

}, issn = {0001-4966}, doi = {10.1121/1.5068534}, url = {http://asa.scitation.org/doi/10.1121/1.5068534}, author = {Juliana R. Moron and Alves, Luiz Cl{\'a}udio P. and de Assis, Carla Viviane and Garcia, Felipe C. and Andriolo, Artur} } @article {53281, title = {Dependence of bottlenose dolphin (Tursiops truncatus) auditory brainstem responses on noise burst rise time, amplitude, and envelope shape}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-09-2018}, pages = {1741 - 1741}, abstract = {

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.]

}, issn = {0001-4966}, doi = {10.1121/1.5067722}, url = {http://asa.scitation.org/doi/10.1121/1.5067722}, author = {Jones, Ryan A. and Finneran, James J. and Mulsow, Jason and Burkard, Robert F.} } @article {53279, title = {Soundscape characteristics in Southern Resident Killer Whale critical habitats}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-09-2018}, pages = {1846 - 1846}, abstract = {

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.]

}, issn = {0001-4966}, doi = {10.1121/1.5068130}, url = {http://asa.scitation.org/doi/10.1121/1.5068130}, author = {Vagle, Svein and O{\textquoteright}Neill, Caitlin and Thornton, Sheila and Yurk, Harald} } @article {53278, title = {Passive echo detection and discrimination in bottlenose dolphins}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-09-2018}, pages = {1741 - 1741}, abstract = {

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.

}, issn = {0001-4966}, doi = {10.1121/1.5067721}, url = {http://asa.scitation.org/doi/10.1121/1.5067721}, author = {Coffinger, Sean P. and Houser, Dorian S. and Finneran, James J. and Mulsow, Jason} } @article {53272, title = {Directional hearing sensitivity for 2{\textendash}30 kHz sounds in the bottlenose dolphin (Tursiops truncatus)}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-09-2018}, pages = {1741 - 1741}, abstract = {

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.

}, issn = {0001-4966}, doi = {10.1121/1.5067720}, url = {http://asa.scitation.org/doi/10.1121/1.5067720}, author = {Accomando, Alyssa W. and Mulsow, Jason and Branstetter, Brian K. and Finneran, James J. and Jenkins, Keith} } @article {53240, title = {Bone-conducted sound in a dolphin{\textquoteright}s mandible: Experimental investigation of elastic waves mediating information on sound source position}, journal = {The Journal of the Acoustical Society of America}, volume = {144}, year = {2018}, month = {Jan-10-2018}, pages = {2213 - 2224}, abstract = {

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\&$\#$39; biosonar is high, independently of where the source is. Binaural/spectral cues are unlikely to account for this remarkable skill. In this paper, bone-conducted sound in a dolphin\&$\#$39;s mandible is studied, investigating its possible contribution to sound localization. Experiments are conducted in a water tank by deploying, on the horizontal and median planes of the skull, ultrasound sources that emit synthetic clicks between 45 and 55\ kHz. Elastic waves propagating through the mandible are measured at the pan bones and used to localize source positions via either binaural cues or a correlation-based full-waveform algorithm. Exploiting the full waveforms and, most importantly, reverberated coda, it is possible to enhance the accuracy of source localization in the vertical plane and achieve similar resolution of horizontal- vs vertical-plane sources. The results noted in this paper need to be substantiated by further experimental work, accounting for soft tissues and making sure that the data are correctly mediated to the internal ear. If confirmed, the results would favor the idea that dolphin\&$\#$39;s echolocation skills rely on the capability to analyze the coda of biosonar echoes.

}, issn = {0001-4966}, doi = {10.1121/1.5063356}, url = {http://asa.scitation.org/doi/10.1121/1.5063356}, author = {Reinwald, Michael and Grimal, Quentin and Marchal, Jacques and Catheline, Stefan and Boschi, Lapo} } @article {53029, title = {Description and classification of Indian Ocean humpback dolphin ( Sousa plumbea ) whistles recorded off the Sindhudurg coast of Maharashtra, India}, journal = {Marine Mammal Science}, volume = {34}, year = {2018}, month = {Jan-07-2018}, pages = {755 - 776}, abstract = {

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.

}, keywords = {humpback dolphin, India, passive acoustic monitoring, Sousa plumbea, whistles}, doi = {10.1111/mms.v34.310.1111/mms.12479}, url = {http://doi.wiley.com/10.1111/mms.v34.3}, author = {Bopardikar, Isha and Sutaria, Dipani and Sule, Mihir and Jog, Ketki and Patankar, Vardhan and Klinck, Holger} } @article {52565, title = {Bottlenose dolphins that forage with artisanal fishermen whistle differently}, journal = {Ethology}, volume = {123}, year = {2017}, month = {Jan-12-2017}, pages = {906 - 915}, abstract = {

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.

}, doi = {10.1111/eth.2017.123.issue-1210.1111/eth.12665}, url = {http://doi.wiley.com/10.1111/eth.2017.123.issue-12}, author = {Romeu, Bianca and Cantor, Mauricio and Bezamat, Carolina and Sim{\~o}es-Lopes, Paulo C. and Daura-Jorge, F{\'a}bio G.}, editor = {Ebensperger, L.} } @article {47326, title = {Successful suction-cup tagging of a small delphinid species, Stenella attenuata: Insights into whistle characteristics}, journal = {Marine Mammal Science}, year = {2016}, month = {Jan-12-2016}, doi = {10.1111/mms.12376}, url = {http://doi.wiley.com/10.1111/mms.12376}, author = {Silva, Tammy L. and Laela S. Sayigh and Baird, Robin W.} } @article {47322, title = {Acoustic classification of dolphins in the California Current using whistles, echolocation clicks, and burst pulses}, journal = {Marine Mammal Science}, year = {2016}, month = {Jan-12-2016}, abstract = {

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.

}, keywords = {acoustics, burst pulses, classification, delphinids, dolphins, echolocation clicks, whistles}, doi = {10.1111/mms.12381}, url = {http://doi.wiley.com/10.1111/mms.12381}, author = {Rankin, Shannon and Archer, Frederick and Keating, Jennifer L. and Oswald, Julie N. and Oswald, Michael and Curtis, Alex and Barlow, Jay} } @article {16150, title = {Different modes of acoustic communication in deep-diving short-finned pilot whales (Globicephala macrorhynchus)}, journal = {Marine Mammal Science}, volume = {33}, year = {2017}, month = {Jan-01-2017}, pages = {59 - 79}, doi = {10.1111/mms.2017.33.issue-110.1111/mms.12344}, url = {http://doi.wiley.com/10.1111/mms.2017.33.issue-1}, author = {P{\'e}rez, Jacobo Marrero and Jensen, Frants H. and Rojano-Do{\~n}ate, Laia and Aguilar de Soto, Natacha} }