Identification of animal movement patterns using tri-axial magnetometry

Show simple item record Williams, Hannah J. Holton, Mark D. Shepard, Emily L.C. Largey, Nicola Norman, Brad Ryan, Peter G. Duriez, Olivier Scantlebury, Michael Quintana, Flavio Magowan, Elizabeth A. Marks, Nikki J. Alagaili, Abdulaziz N. Bennett, Nigel Charles Wilson, Rory P. 2017-04-24T09:05:29Z 2017-04-24T09:05:29Z 2017-03-27
dc.description Additional file 1: Comparison of tri-axial acceleration and tri-axial magnetometer data for detection of behaviours using template matching. en_ZA
dc.description.abstract BACKGROUND : Accelerometers are powerful sensors in many bio-logging devices, and are increasingly allowing researchers to investigate the performance, behaviour, energy expenditure and even state, of free-living animals. Another sensor commonly used in animal-attached loggers is the magnetometer, which has been primarily used in dead-reckoning or inertial measurement tags, but little outside that. We examine the potential of magnetometers for helping elucidate the behaviour of animals in a manner analogous to, but very different from, accelerometers. The particular responses of magnetometers to movement means that there are instances when they can resolve behaviours that are not easily perceived using accelerometers. METHODS : We calibrated the tri-axial magnetometer to rotations in each axis of movement and constructed 3- dimensional plots to inspect these stylised movements. Using the tri-axial data of Daily Diary tags, attached to individuals of number of animal species as they perform different behaviours, we used these 3-d plots to develop a framework with which tri-axial magnetometry data can be examined and introduce metrics that should help quantify movement and behaviour. RESULTS : Tri-axial magnetometry data reveal patterns in movement at various scales of rotation that are not always evident in acceleration data. Some of these patterns may be obscure until visualised in 3D space as tri-axial spherical plots (m-spheres). A tag-fitted animal that rotates in heading while adopting a constant body attitude produces a ring of data around the pole of the m-sphere that we define as its Normal Operational Plane (NOP). Data that do not lie on this ring are created by postural rotations of the animal as it pitches and/or rolls. Consequently, stereotyped behaviours appear as specific trajectories on the sphere (m-prints), reflecting conserved sequences of postural changes (and/or angular velocities), which result from the precise relationship between body attitude and heading. This novel approach shows promise for helping researchers to identify and quantify behaviours in terms of animal body posture, including heading. CONCLUSION : Magnetometer-based techniques and metrics can enhance our capacity to identify and examine animal behaviour, either as a technique used alone, or one that is complementary to tri-axial accelerometry. en_ZA
dc.description.department Zoology and Entomology en_ZA
dc.description.librarian am2017 en_ZA
dc.description.sponsorship Funding was provided by the Deanship of Scientific Research at the King Saud University, Saudi Arabia (project number IRG_15-38) and logistic and financial support by the South African National Antarctic Programme through the National Research Foundation. HW is funded by a Swansea University Studentship. This project as a whole was made possible by a generous grant from the Royal Society/Wolfson fund to build the Swansea University Visualization Suite. en_ZA
dc.description.uri en_ZA
dc.identifier.citation Williams, HJ, Holton, MD, Shepard, ELC, Largey, N, Norman, B, Ryan, PG, Duriez, O, Scantlebury, M, Quintana, F, Magowan, EA, Marks, NJ, Alagaili, AN, Bennett, NC & Wilson, RP 2017, 'Identification of animal movement patterns using tri-axial magnetometry', Movement Ecology, vol. 5, art. no. 6, pp. 1-14. en_ZA
dc.identifier.issn 2051-3933 (online)
dc.identifier.other 10.1186/s40462-017-0097-x
dc.language.iso en en_ZA
dc.publisher BioMed Central en_ZA
dc.rights © The Author(s). 2017. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License ( en_ZA
dc.subject Magnetometer en_ZA
dc.subject Magnetic field en_ZA
dc.subject Bio-logging en_ZA
dc.subject Accelerometer en_ZA
dc.subject Animal behaviour en_ZA
dc.subject Behavioural consistency en_ZA
dc.subject Normal operational plane en_ZA
dc.subject Angular velocity en_ZA
dc.title Identification of animal movement patterns using tri-axial magnetometry en_ZA
dc.type Article en_ZA

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