02346nas a2200313 4500008004100000245010600041210006900147260001600216520139500232653001901627653001701646653001901663653002101682653001501703653001301718653001701731653002201748653002101770653002701791100002101818700001801839700002301857700002001880700002001900700002101920700002001941700002201961856004901983 2018 eng d00aA 2.6-gram sound and movement tag for studying the acoustic scene and kinematics of echolocating bats0 a26gram sound and movement tag for studying the acoustic scene an cApr-10-20193 a

1.To study sensorimotor behaviour in wild animals, it is necessary to synchronously record the sensory inputs available to the animal, and its movements. To do this, we have developed a biologging device that can record the primary sensory information and the associated movements during foraging and navigating in echolocating bats.

2.This 2.6 ‐gram tag records the sonar calls and echoes from an ultrasonic microphone, while simultaneously sampling fine‐scale movement in three dimensions from wideband accelerometers and magnetometers. In this study, we tested the tag on an European noctula (Nyctalus noctula) during target approaches and on four big brown bats (Eptesicus fuscus) during prey interception in a flight room.

3.We show that the tag records both the outgoing calls and echoes returning from objects at biologically relevant distances. Inertial sensor data enables the detection of behavioural events such as flying, turning, and resting. In addition, individual wing‐beats can be tracked and synchronized to the bat's sound emissions to study the coordination of different motor events.

4.By recording the primary acoustic flow of bats concomitant with associated behaviours on a very fine time‐scale, this type of biologging method will foster a deeper understanding of how sensory inputs guide feeding behaviours in the wild.

10aAccelerometers10aarchival tag10aauditory scene10abat echolocation10abiologging10aechogram10aechoic scene10aflight kinematics10ainertial sensors10asensory-motor response1 aStidsholt, Laura1 aJohnson, Mark1 aBeedholm, Kristian1 aJakobsen, Lasse1 aKugler, Kathrin1 aBrinkløv, Signe1 aSalles, Angeles1 aMoss, Cynthia, F. uhttp://doi.wiley.com/10.1111/2041-210X.1310802034nas a2200157 4500008004100000022001300041245009300054210006900147260001600216300001400232490000800246520134600254100002001600700002301620856023301643 2019 eng d a0003682X00aPractical implementation of auditory time and frequency weighting in marine bioacoustics0 aPractical implementation of auditory time and frequency weightin cJan-02-2019 a137 - 1430 v1453 a

Much effort is currently directed at describing the behavioral reactions of marine mammals following exposure to sound with the aim of deriving generalized thresholds and dose-response functions. The perceived loudness of a given sound is a candidate for a common metric for sound exposure. The loudness of a signal relates to various factors, including the stimulus duration and frequency content, and it can be approximated by an appropriate time and frequency weighting of the signal. Auditory frequency weighting is achieved by applying a frequency weighting function (band-pass filter), with a frequency response resembling the shape of an inverted audiogram. Temporal weighting may be achieved by computing the running rms-average (Leq) with a time constant that is comparable to that of the mammalian auditory system. The practical implementation of such weighting functions are presented in the form of Matlab functions. These functions generate output signals that are weighted according to current recommendations for different groups of marine mammals. With these functions, it is possible to derive the weighted peak Leq of a signal, which is likely to be a good proxy for the loudness of the signal. Ultimately, this weighted level is conjectured to be a predictor of behavioral response of marine mammals to the sound.

1 aTougaard, Jakob1 aBeedholm, Kristian uhttps://linkinghub.elsevier.com/retrieve/pii/S0003682X18303967https://api.elsevier.com/content/article/PII:S0003682X18303967?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0003682X18303967?httpAccept=text/plain02009nas a2200181 4500008004100000022001400041245013400055210006900189260001600258300001400274490000800288520140200296100002001698700001601718700002301734700001901757856005101776 2018 eng d a0001-496600aVariability of the inter-pulse interval in sperm whale clicks with implications for size estimation and individual identification0 aVariability of the interpulse interval in sperm whale clicks wit cJan-07-2018 a365 - 3740 v1443 a

Sperm whales generate multi-pulsed clicks for echolocation and communication with an inter-pulse interval (IPI) determined by the size of their hypertrophied sound producing nose. The IPI has therefore been used to estimate body size and distinguish between individuals, and it has been hypothesized that conspecifics may use IPIs to recognize each other. However, the degree to which IPIs vary within individuals has not explicitly been tested, and therefore the inherent precision of this measure and its applicability for size estimation for researchers and sperm whales alike remain unknown. Here, the variability in IPI from both animal-borne Dtags and far-field recordings from echolocating and communicating sperm whales is quantified. Three different automatic methods (envelope, cepstrum, and cross-correlation) are tested and it is found that the envelope approach results in the least dispersion. Furthermore, it is shown that neither growth, depth, nor recording aspect fully explains the observed variability among clicks recorded from the same individual. It is proposed that dynamics in the soft structures of the nose are affecting IPIs, resulting in a variation of approximately 0.2 ms. Therefore, it is recommended that this variation be considered in IPI studies and that IPIs may have limited functionality as an identity cue among large groups of conspecifics.

1 aBøttcher, Anne1 aGero, Shane1 aBeedholm, Kristian1 aWhitehead, Hal uhttp://asa.scitation.org/doi/10.1121/1.5047657