Wang K, Mattern E, Ritz T
Department of Physics and Astronomy, University of California, Irvine, CA 92697-4575, USA.
Phys Biol. 2006 Oct 4;3(3):220-31. doi: 10.1088/1478-3975/3/3/007.
Behavioral researchers have attached magnets to birds during orientation experiments, assuming that such magnets will disrupt their ability to obtain magnetic information. Here, we investigate the effect of an attached magnet on the ability to derive directional information from a radical-pair based compass mechanism. We outline in some detail the geometrical symmetries that would allow a bird to identify magnetic directions in a radical-pair based compass. We show that the artificial field through an attached magnet will quickly disrupt the birds' ability to distinguish pole-ward from equator-ward headings, but that much stronger fields are necessary to disrupt their ability to detect the magnetic axis. Together with estimates of the functional limits of a radical-pair based compass, our calculations suggest that artificial fields of comparable size to the geomagnetic field are not generally sufficient to render a radical-pair based compass non-functional.
行为研究人员在定向实验中给鸟类附着磁铁，假定此类磁铁会干扰它们获取磁信息的能力。在此，我们研究附着磁铁对基于自由基对的罗盘机制推导方向信息能力的影响。我们较为详细地概述了几何对称性，这种对称性能使鸟类在基于自由基对的罗盘中识别磁方向。我们表明，通过附着磁铁产生的人工磁场会迅速干扰鸟类区分向极方向和向赤道方向飞行的能力，但需要更强得多的磁场才能干扰它们检测磁轴的能力。结合对基于自由基对的罗盘功能极限的估计，我们的计算表明，与地磁场大小相当的人工磁场通常不足以使基于自由基对的罗盘失效。
