@article {53241, title = {A 2.6-gram sound and movement tag for studying the acoustic scene and kinematics of echolocating bats}, journal = {Methods in Ecology and Evolution}, year = {2018}, month = {Apr-10-2019}, abstract = {

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\&$\#$39;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.

}, keywords = {Accelerometers, archival tag, auditory scene, bat echolocation, biologging, echogram, echoic scene, flight kinematics, inertial sensors, sensory-motor response}, doi = {10.1111/2041-210X.13108}, url = {http://doi.wiley.com/10.1111/2041-210X.13108}, author = {Stidsholt, Laura and Johnson, Mark and Beedholm, Kristian and Jakobsen, Lasse and Kugler, Kathrin and Brinkl{\o}v, Signe and Salles, Angeles and Moss, Cynthia F.} } @article {52670, title = {The Chirocopter: a UAV for recording sound and video of bats at altitude}, journal = {Methods in Ecology and Evolution}, year = {2018}, month = {Feb-03-2018}, abstract = {

1.Most recordings of bats are conducted with fixed equipment, which relies on opportunistic data collection. Unmanned aerial vehicles (such as drones) are considered inappropriate for recording bats due to ultrasound noise constraints.

2.We developed a UAV system that physically isolates UAV noise so we can record, with 3D maneuverability, ultrasonic audio and spatial thermal data of bat flight at altitude.

3.We tested the noise of our UAV with various payloads and microphone configurations to characterize the ultrasonic noise of our system, physically isolate drone noise from the microphone, and maximize UAV flight performance.

4.Over 84 minutes of recordings, we captured 3,847 echolocation signals from bats with corresponding thermal data of bat flight. Our system provides a feasible mechanism to capture both acoustic and video data of bats aloft at flexible locations and altitudes.

5.We include information on how to extend our method to apply to acoustic recordings in the audible (20 Hz-20 kHz) range for recording sounds of other taxa.

}, doi = {10.1111/2041-210X.12992}, url = {http://doi.wiley.com/10.1111/2041-210X.12992}, author = {Fu, Yanqing and Kinniry, Morgan and Kloepper, Laura N.} } @article {47699, title = {MatlabHTK: a simple interface for bioacoustic analyses using hidden Markov models}, journal = {Methods in Ecology and Evolution}, volume = {8}, year = {2017}, month = {Jan-05-2017}, pages = {615 - 621}, abstract = {

1.Passive bioacoustic recording devices are now widely available and able to continuously record remotely located sites for extended periods, offering great potential for wildlife monitoring and management. Analysis of the huge data sets generated, in particular for specific biotic sound recognition, remains a critical bottleneck for widespread adoption of these technologies as current methods are labour intensive.

2. Several methods borrowed from speech processing frameworks, such as hidden Markov models, have been successful in analysing bioacoustic data, but the software implementations can be expensive and difficult to use for non-specialists involved in wildlife conservation. To remedy this, we present a software interface to a popular speech recognition system making it possible for non-experts to implement hidden Markov models for bioacoustic signal processing. Octave/Matlab functions are used to simplify the set-up and the definition of a bioacoustic signal recogniser as well as the analysis of the results.

3. We present the different functions as a workflow. To demonstrate how the package can be used, we give the results of an analysis of a bioacoustic monitoring data set to detect the nocturnal presence and behaviour of a cryptic seabird species, the common diving petrel Pelecanoides urinatrix urinatrix, from Northern New Zealand.


4. We show that the package MatlabHTK can be used efficiently to reconstruct the daily patterns of colony activity in the common diving petrel.

}, keywords = {bioacoustics, hidden Markov models, monitoring, seabird}, doi = {10.1111/mee3.2017.8.issue-510.1111/2041-210X.12688}, url = {http://doi.wiley.com/10.1111/mee3.2017.8.issue-5}, author = {Ranjard, Louis and Reed, Benjamin S. and Landers, Todd J. and Rayner, Matt J. and Friesen, Megan R. and Sagar, Rachel L. and Dunphy, Brendon J.}, editor = {Gaggiotti, Oscar} } @article {16409, title = {Potential for coupling the monitoring of bush-crickets with established large-scale acoustic monitoring of bats}, journal = {Methods in Ecology and Evolution}, year = {2017}, month = {Jan-01-2017}, abstract = {

Monitoring biodiversity over large spatial and temporal scales is crucial for assessing the impact of global changes and environmental mitigation measures. However, large-scale monitoring of invertebrates remains poorly developed despite the importance of these organisms in ecosystem functioning. Exciting possibilities applicable to professional and citizen science are offered by new recording techniques and methods of semi-automated species recognition based on sound detection.


Static broad-spectrum detectors deployed to record throughout whole nights have been recommended for standardised acoustic monitoring of bats, but they have the potential to also collect acoustic data for other species groups. Large-scale deployment of such systems is only viable when combined with robust automated species identification algorithms. Here we examine the potential of such a system for detecting, identifying and monitoring bush-crickets (Orthoptera of the family Tettigoniidae). We use incidental sound recordings generated by an extensive citizen science bat survey and recordings from intensive site surveys to test a semi-automated step-wise method with a classifier for assigning species identities. We assess species\’ diel activity patterns to make recommendations for survey timing and interpretation of existing nocturnal data sets and consider the feasibility of determining site occupancy.

Of six species of bush-crickets, the species classifier achieved over 85\% accuracy for three, speckled bush-cricket, dark bush-cricket and Roesel\&$\#$39;s bush-cricket. It should be possible to automatically scan recordings for these species with minimal manual validation. Further refinement of the classifier is required for the three remaining species, in particular for the acoustically similar short-winged conehead and long-winged conehead. Diel activity patterns are species specific and it may be necessary to adjust the hours over which the detectors record to increase detection of key species, but this must be weighed against the costs in terms of increased memory and battery use and equipment security during daytime.

We conclude that with logistical support and centralised semi-automated species identification it is now possible for the public to contribute to large-scale acoustic monitoring of Orthoptera while recording bats. Further innovation of sound classifier algorithms is needed and would be aided by improved reference sound libraries from multiple locations spanning species\’ ranges.

}, doi = {10.1111/2041-210X.12720}, url = {http://doi.wiley.com/10.1111/2041-210X.12720}, author = {Newson, Stuart E. and Bas, Yves and Murray, Ash and Gillings, Simon} } @article {15452, title = {Acoustic monitoring for conservation in tropical forests: examples from forest elephants}, journal = {Methods in Ecology and Evolution}, year = {2017}, month = {Jan-01-2017}, abstract = {

1. The accelerating loss of biodiversity worldwide demands effective tools for monitoring animal populations and informing conservation action. In habitats where direct observation is difficult (rain forests, oceans), or for cryptic species (shy, nocturnal), passive acoustic monitoring (PAM) provides cost-effective, unbiased data collec- tion. PAM has broad applicability in terrestrial environments, particularly tropical rain forests.


2. Using examples from studies of forest elephants in Central African rainforest,we show how PAM can be used to investigate cryptic behaviour, mechanisms of communication, estimate population size, quantify threats, and assess the efficacy of conservation strategies. We discuss the methodologies, requirements, and challenges of obtaining these data using acoustics. Where applicable, we compare these methods to more traditional approaches.


3. While PAM methods and associated analysis are maturing rapidly, mechanisms are needed for processing the dense raw data efficiently with standard computer hardware, speeding development of detection algorithms, and harnessing communication networks to move data from the field to research facilities.


4. Passive acoustic monitoring is a viable and cost-effective tool for conservation and should be incorporated in monitoring schemes much more broadly. The capability to quickly assess changes in behaviour, population size, and landscape use, simultaneously over large geographical areas, makes this approach attractive for detecting human-induced impacts and for assessing the success of conservation strategies.

}, keywords = {anthropogenic impacts, anti-poaching, bioacoustics, cryptic species, density estimate, law enforcement monitoring, Loxodonta cyclotis, passive acoustic monitoring, signal detection, SMART}, doi = {10.1111/2041-210X.12730}, url = {http://doi.wiley.com/10.1111/2041-210X.12730}, author = {Wrege, Peter H. and Rowland, Elizabeth D. and Keen, Sara and Shiu, Yu} }