Department of Mathematics, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
J Theor Biol. 2011 Jan 21;269(1):273-9. doi: 10.1016/j.jtbi.2010.10.036. Epub 2010 Nov 3.
All mobile animals respond to gradients in signals in their environment, such as light, sound, odours and magnetic and electric fields, but it remains controversial how they might use these signals to navigate over long distances. The Earth's surface is essentially two-dimensional, so two stimuli are needed to act as coordinates for navigation. However, no environmental fields are known to be simple enough to act as perpendicular coordinates on a two-dimensional grid. Here, we propose a model for navigation in which we assume that an animal has a simplified 'cognitive map' in which environmental stimuli act as perpendicular coordinates. We then investigate how systematic deviation of the contour lines of the environmental signals from a simple orthogonal arrangement can cause errors in position determination and lead to systematic patterns of directional errors in initial homing directions taken by pigeons. The model reproduces patterns of initial orientation errors seen in previously collected data from homing pigeons, predicts that errors should increase with distance from the loft, and provides a basis for efforts to identify further sources of orientation errors made by homing pigeons.
所有的移动动物都会对环境中的信号梯度做出反应，例如光、声、气味以及磁场和电场，但它们如何利用这些信号进行长距离导航仍然存在争议。地球表面本质上是二维的，因此需要两个刺激作为导航的坐标。然而，目前还没有已知的环境场能够简单地作为二维网格上的垂直坐标。在这里，我们提出了一种导航模型，我们假设动物有一个简化的“认知地图”，其中环境刺激作为垂直坐标。然后，我们研究了环境信号的轮廓线如何从简单的正交排列系统地偏离，这可能导致位置确定中的误差，并导致鸽子初始归巢方向的定向误差出现系统模式。该模型再现了从归巢鸽子之前收集的数据中观察到的初始定向误差模式，预测误差应该随离鸽舍的距离增加而增加，并为确定归巢鸽子的其他定向误差来源提供了基础。
