Postlethwaite Claire M, Walker Michael M
Department of Mathematics, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
J Theor Biol. 2014 Dec 21;363:134-44. doi: 10.1016/j.jtbi.2014.08.014. Epub 2014 Aug 19.
Many animals are believed to navigate using environmental signals such as light, sound, odours and magnetic fields. However, animals rarely navigate directly to their target location, but instead make a series of navigational errors which are corrected during transit. In previous work, we introduced a model showing that differences between an animal׳s 'cognitive map' of the environmental signals used for navigation and the true nature of these signals caused a systematic pattern in orientation errors when navigation begins. The model successfully predicted the pattern of errors seen in previously collected data from homing pigeons, but underestimated the amplitude of the errors. In this paper, we extend our previous model to include more complicated distortions of the contour lines of the environmental signals. Specifically, we consider the occurrence of critical points in the fields describing the signals. We consider three scenarios and compute orientation errors as parameters are varied in each case. We show that the occurrence of critical points can be associated with large variations in initial orientation errors over a small geographic area. We discuss the implications that these results have on predicting how animals will behave when encountering complex distortions in any environmental signals they use to navigate.
许多动物被认为利用光、声音、气味和磁场等环境信号进行导航。然而，动物很少能直接导航到目标位置，而是会出现一系列导航错误，并在行进过程中得到纠正。在之前的研究中，我们提出了一个模型，该模型表明，动物用于导航的环境信号的“认知地图”与这些信号的真实性质之间的差异，在导航开始时会导致定向误差出现系统性模式。该模型成功预测了之前从归巢鸽子收集的数据中出现的误差模式，但低估了误差幅度。在本文中，我们扩展了之前的模型，以纳入环境信号等高线更复杂的畸变情况。具体来说，我们考虑了描述信号的场中临界点的出现。我们考虑了三种情况，并在每种情况下改变参数来计算定向误差。我们表明，临界点的出现可能与小地理区域内初始定向误差的大幅变化有关。我们讨论了这些结果对于预测动物在遇到它们用于导航的任何环境信号中的复杂畸变时的行为方式所具有的意义。
