01935nas a2200157 4500008004100000245014700041210006900188260001600257490000600273520135000279100002301629700002201652700002301674700002601697856005401723 2019 eng d00aMigrating eastern North Pacific gray whale call and blow rates estimated from acoustic recordings, infrared camera video, and visual sightings0 aMigrating eastern North Pacific gray whale call and blow rates e cJan-12-20190 v93 a

During the eastern North Pacific gray whale 2014–2015 southbound migration, acoustic call recordings, infrared blow detections, and visual sightings were combined to estimate cue rates, needed to convert detections into abundance. The gray whale acoustic call rate ranged from 2.3–24 calls/whale/day during the peak of the southbound migration with an average of 7.5 calls/whale/day over both the southbound and northbound migrations. The average daily calling rate increased between 30 December–13 February. With a call rate model, we estimated that 4,340 gray whales migrated south before visual observations began on 30 December, which is 2,829 more gray whales than used in the visual estimate, and would add approximately 10% to the abundance estimate. We suggest that visual observers increase their survey effort to all of December to document gray whale presence. The infrared camera blow rate averaged 49 blows/whale/hour over 5–8 January. Probability of detection of a whale blow by the infrared camera was the same at night as during the day. However, probability of detection decreased beyond 2.1 km offshore, whereas visual sightings revealed consistent whale densities up to 3 km offshore. We suggest that future infrared camera surveys use multiple cameras optimised for different ranges offshore.

1 aGuazzo, Regina, A.1 aWeller, David, W.1 aEurope, Hollis, M.1 aD’Spain, Gerald, L. uhttp://www.nature.com/articles/s41598-019-49115-y02054nas a2200169 4500008004100000245010200041210006900143260001600212490000600228520148700234100002301721700002701744700002101771700001601792700002201808856005401830 2019 eng d00aDeep Machine Learning Techniques for the Detection and Classification of Sperm Whale Bioacoustics0 aDeep Machine Learning Techniques for the Detection and Classific cJan-12-20190 v93 a

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

1 aBermant, Peter, C.1 aBronstein, Michael, M.1 aWood, Robert, J.1 aGero, Shane1 aGruber, David, F. uhttp://www.nature.com/articles/s41598-019-48909-401971nas a2200121 4500008004100000245012700041210006900168260001600237490000600253520151000259100002601769856005401795 2019 eng d00aNoise-induced vocal plasticity in urban white-crowned sparrows does not involve adjustment of trill performance components0 aNoiseinduced vocal plasticity in urban whitecrowned sparrows doe cJan-12-20190 v93 a

Background noise can interfere with acoustic communication and subsequently influence signaling behavior. Immediate signaling flexibility (ISF) is a context-dependent form of behavioral plasticity that allows animals to temporarily change their acoustic behavior in response to noise fluctuations and potentially improve the chances of successful communication in noisy environments. The adaptive value of ISF is ultimately contingent on the response of the intended receiver, and there are differential effects on receiver response depending on which signal component is modified. However, there is scant research on whether ISF involves modification of a signal component specifically linked to mate attraction or territory defense. Our study addresses this knowledge gap and provides important insight into whether males employ short-term signal modification in a manner that could affect mate pairing success in birds. Specifically, we explore the maladaptive potential of ISF in the San Francisco, California population of Zonotrichia leucophrys nuttalli by testing for changes in trill bandwidth and rate—the specific trill structure components known to influence the receiver’s perception of vocal performance in this species—before and during noise broadcast experiments. Although Zonotrichia leucophrys nuttalli are capable of ISF, we found no evidence that noise induces temporary adjustment of the trill structure traits used by receivers to assess vocal performance.

1 aGentry, Katherine, E. uhttp://www.nature.com/articles/s41598-018-36276-501594nas a2200145 4500008004100000245009400041210007000135260001600205490000600221520109500227100002501322700002601347700002101373856005401394 2019 eng d00aDeaf moths employ acoustic Müllerian mimicry against bats using wingbeat-powered tymbals0 aDeaf moths employ acoustic Müllerian mimicry against bats using  cJan-12-20190 v93 a

Emitting ultrasound upon hearing an attacking bat is an effective defence strategy used by several moth taxa. Here we reveal how Yponomeuta moths acquire sophisticated acoustic protection despite being deaf themselves and hence unable to respond to bat attacks. Instead, flying Yponomeuta produce bursts of ultrasonic clicks perpetually; a striated patch in their hind wing clicks as the beating wing rotates and bends. This wing structure is strikingly similar to the thorax tymbals with which arctiine moths produce their anti-bat sounds. And indeed, Yponomeuta sounds closely mimic such arctiine signals, revealing convergence in form and function. Because both moth taxa contain noxious compounds, we conclude they are mutual Müllerian acoustic mimics. Yponomeuta’s perpetual clicking would however also attract bat predators. In response, their click amplitude is reduced and affords acoustic protection just as far as required, matching the distance over which bat biosonar would pick up Yponomeuta echoes anyway – advanced acoustic defences for a deaf moth.

1 aO’Reilly, Liam, J.1 aAgassiz, David, J. L.1 aNeil, Thomas, R. uhttp://www.nature.com/articles/s41598-018-37812-z01980nas a2200181 4500008004100000245014800041210006900189260001600258490000600274520135900280100001501639700001601654700001901670700001401689700001301703700002801716856005401744 2019 eng d00aLow energy expenditure and resting behaviour of humpback whale mother-calf pairs highlights conservation importance of sheltered breeding areas0 aLow energy expenditure and resting behaviour of humpback whale m cJan-12-20190 v93 a

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

1 aBejder, L.1 aVidesen, S.1 aHermannsen, L.1 aSimon, M.1 aHanf, D.1 aMadsen, Peter, Teglberg uhttp://www.nature.com/articles/s41598-018-36870-701914nas a2200193 4500008004100000245005800041210005800099260001600157490000600173520137300179100002001552700001501572700001701587700001701604700001601621700002001637700001801657856004501675 2017 eng d00aBody size and vocalization in primates and carnivores0 aBody size and vocalization in primates and carnivores cJan-12-20170 v73 a

A fundamental assumption in bioacoustics is that large animals tend to produce vocalizations with lower frequencies than small animals. This inverse relationship between body size and vocalization frequencies is widely considered to be foundational in animal communication, with prominent theories arguing that it played a critical role in the evolution of vocal communication, in both production and perception. A major shortcoming of these theories is that they lack a solid empirical foundation: rigorous comparisons between body size and vocalization frequencies remain scarce, particularly among mammals. We address this issue here in a study of body size and vocalization frequencies conducted across 91 mammalian species, covering most of the size range in the orders Primates (n = 50; ~0.11–120 Kg) and Carnivora (n = 41; ~0.14–250 Kg). We employed a novel procedure designed to capture spectral variability and standardize frequency measurement of vocalization data across species. The results unequivocally demonstrate strong inverse relationships between body size and vocalization frequencies in primates and carnivores, filling a long-standing gap in mammalian bioacoustics and providing an empirical foundation for theories on the adaptive function of call frequency in animal communication.

1 aBowling, D., L.1 aGarcia, M.1 aDunn, J., C.1 aRuprecht, R.1 aStewart, A.1 aFrommolt, K.-H.1 aFitch, W., T. uhttp://www.nature.com/articles/srep4107001862nas a2200193 4500008004100000245009400041210006900135260001600204490000600220520123800226100002301464700002501487700002701512700001901539700002001558700001701578700001901595856005401614 2018 eng d00aMarine mammal acoustic detections in the Greenland and Barents Sea, 2013 – 2014 seasons0 aMarine mammal acoustic detections in the Greenland and Barents S cJan-12-20180 v83 a

While the Greenland and Barents Seas are known habitats for several cetacean and pinniped species there is a lack of long-term monitoring data in this rapidly changing environment. Moreover, little is known of the ambient soundscapes, and increasing off-shore anthropogenic activities can influence the ecosystem and marine life. Baseline acoustic data is needed to better assess current and future soundscape and ecosystem conditions. The analysis of a year of continuous data from three passive acoustic monitoring devices revealed species-dependent seasonal and spatial variation of a large variety of marine mammals in the Greenland and Barents Seas. Sampling rates were 39 and 78 kHz in the respective locations, and all systems were operational at a duty cycle of 2 min on, 30 min off. The research presents a description of cetacean and pinniped acoustic detections along with a variety of unknown low-frequency tonal sounds, and ambient sound level measurements that fall within the scope of the European Marine Strategy Framework (MSFD). The presented data shows the importance of monitoring Arctic underwater biodiversity for assessing the ecological changes under the scope of climate change.

1 aDe Vreese, Steffen1 avan der Schaar, Mike1 aWeissenberger, Jürgen1 aErbs, Florence1 aKosecka, Monika1 aSolé, Marta1 aAndré, Michel uhttp://www.nature.com/articles/s41598-018-34624-z01690nas a2200205 4500008004100000245011100041210006900152260001600221490000600237520101500243100002601258700002901284700002201313700000501335700002001340700002301360700002301383700002401406856005401430 2018 eng d00aA striking new species of leaf warbler from the Lesser Sundas as uncovered through morphology and genomics0 astriking new species of leaf warbler from the Lesser Sundas as u cJan-12-20180 v83 a

Leaf warblers (Aves; Phylloscopidae) are a diverse clade of insectivorous, canopy-dwelling songbirds widespread across the Old World. The taxonomy of Australasian leaf warblers is particularly complex, with multiple species-level divergences between island taxa in the region requiring further scrutiny. We use a combination of morphology, bioacoustics, and analysis of thousands of genome-wide markers to investigate and describe a new species of Phylloscopus leaf warbler from the island of Rote in the Lesser Sundas, Indonesia. We show that this new Rote Leaf Warbler is morphologically and genomically highly distinct from its congenerics, but do not find vocal differentiation between different island taxa. We discuss the behaviour and ecology of this highly distinctive new species, and make recommendations about its conservation status. We believe this constitutes the first description of a novel bird species that is partly based on insights from massive amounts of genome-wide DNA markers.

1 aNg, Nathaniel., S. R.1 aPrawiradilaga, Dewi., M.1 aNg, Elize., Y. X.1 a1 aAshari, Hidayat1 aTrainor, Colin, R.1 aVerbelen, Philippe1 aRheindt, Frank., E. uhttp://www.nature.com/articles/s41598-018-34101-701987nas a2200157 4500008004100000245010400041210006900145260001600214490000600230520146900236100001701705700002501722700001801747700001901765856004501784 2016 eng d00aLinking the sender to the receiver: vocal adjustments by bats to maintain signal detection in noise0 aLinking the sender to the receiver vocal adjustments by bats to  cJan-11-20160 v53 a

Short-term adjustments of signal characteristics allow animals to maintain reliable communication in noise. Noise-dependent vocal plasticity often involves simultaneous changes in multiple parameters. Here, we quanti ed for the  rst time the relative contributions of signal amplitude, duration,
and redundancy for improving signal detectability in noise. To this end, we used a combination of behavioural experiments on pale spear-nosed bats (Phyllostomus discolor) and signal detection models. In response to increasing noise levels, all bats raised the amplitude of their echolocation calls by 1.8–7.9 dB (the Lombard e ect). Bats also increased signal duration by 13%–85%, corresponding to an increase in detectability of 1.0–5.3 dB. Finally, in some noise conditions, bats increased signal redundancy by producing more call groups. Assuming optimal cognitive integration, this could result in a further detectability improvement by up to 4 dB. Our data show that while the main improvement in signal detectability was due to the Lombard e ect, increasing signal duration and redundancy can also contribute markedly to improving signal detectability. Overall, our  ndings demonstrate that
the observed adjustments of signal parameters in noise are matched to how these parameters are processed in the receiver’s sensory system, thereby facilitating signal transmission in  uctuating environments.

1 aLuo, Jinhong1 aGoerlitz, Holger, R.1 aBrumm, Henrik1 aWiegrebe, Lutz uhttp://www.nature.com/articles/srep18556