Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published April 6, 2010 | Supplemental Material + Published
Journal Article Open

Biophysics of magnetic orientation: strengthening the interface between theory and experimental design


The first demonstrations of magnetic effects on the behaviour of migratory birds and homing pigeons in laboratory and field experiments, respectively, provided evidence for the longstanding hypothesis that animals such as birds that migrate and home over long distances would benefit from possession of a magnetic sense. Subsequent identification of at least two plausible biophysical mechanisms for magnetoreception in animals, one based on biogenic magnetite and another on radical-pair biochemical reactions, led to major efforts over recent decades to test predictions of the two models, as well as efforts to understand the ultrastructure and function of the possible magnetoreceptor cells. Unfortunately, progress in understanding the magnetic sense has been challenged by: (i) the availability of a relatively small number of techniques for analysing behavioural responses to magnetic fields by animals; (ii) difficulty in achieving reproducible results using the techniques; and (iii) difficulty in development and implementation of new techniques that might bring greater experimental power. As a consequence, laboratory and field techniques used to study the magnetic sense today remain substantially unchanged, despite the huge developments in technology and instrumentation since the techniques were developed in the 1950s. New methods developed for behavioural study of the magnetic sense over the last 30 years include the use of laboratory conditioning techniques and tracking devices based on transmission of radio signals to and from satellites. Here we consider methodological developments in the study of the magnetic sense and present suggestions for increasing the reproducibility and ease of interpretation of experimental studies. We recommend that future experiments invest more effort in automating control of experiments and data capture, control of stimulation and full blinding of experiments in the rare cases where automation is impossible. We also propose new experiments to confirm whether or not animals can detect magnetic fields using the radical-pair effect together with an alternate hypothesis that may explain the dependence on light of responses by animals to magnetic field stimuli.

Additional Information

© 2010 The Royal Society. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Received November 11, 2009; Accepted December 24, 2009. Published online before print January 13, 2010. Supported by Human Frontiers Science Program grant RGP0028 to the authors, NIH grant 5R21GM76417 to J.L.K. and DFG grant Wi 1828/4 to M.W. We also thank Prof. David B. Rutledge of Caltech for advice on how to short the radio-frequency antennas for a blind control and Profs Cecile Fradin of McMaster University and Peter McNaughton of Cambridge University for helpful discussions on photo bleaching techniques.

Attached Files

Published - Kirschvink2010p7372J_R_Soc_Interface.pdf

Supplemental Material - rsif20090491supp1.pdf


Files (701.8 kB)
Name Size Download all
24.2 kB Preview Download
677.6 kB Preview Download

Additional details

August 21, 2023
October 20, 2023