Greenwood Verity J, Smith Emma L, Church Stuart C, Partridge Julian C
Ecology of Vision Research Laboratory, School of Biological Sciences, University of Bristol.
J Exp Biol. 2003 Sep;206(Pt 18):3201-10. doi: 10.1242/jeb.00537.
Many animals have sensitivity to the e-vector of linearly polarised light, which may assist in visually mediated behaviours such as navigation, signalling and foraging. However, it is still controversial as to whether birds possess polarisation sensitivity. Several studies have found that altering the polarisation patterns of the broad visual field surrounding birds alters their intended migratory orientation. However, electrophysiological tests have failed to elicit evidence for polarisation sensitivity in birds, and the mechanism by which birds might perceive polarised light is unknown. In this experiment, we trained Japanese quail and European starlings to discriminate stimuli differing in their polarisation pattern. Although both quail and starlings were able to discriminate stimuli in which the stimulus sub-components either differed or had the same radiant intensity (the control task), they were unable to discriminate stimuli in which the e-vector orientations of the stimulus sub-components either differed by 90 degrees or had the same angle of polarisation. The birds' successful performance on the control task, but failure to complete the polarisation task, demonstrated that they had all the necessary cognitive abilities to make the discrimination except sensitivity to angle of polarisation. We conclude that quail and starlings are unable to use polarisation cues in this foraging task.
许多动物对线性偏振光的电场矢量敏感，这可能有助于视觉介导的行为，如导航、信号传递和觅食。然而，鸟类是否具有偏振光敏感性仍存在争议。几项研究发现，改变鸟类周围广阔视野的偏振模式会改变它们预期的迁徙方向。然而，电生理测试未能找到鸟类具有偏振光敏感性的证据，而且鸟类感知偏振光的机制也尚不清楚。在本实验中，我们训练了日本鹌鹑和欧洲椋鸟，使其能够区分偏振模式不同的刺激。虽然鹌鹑和椋鸟都能够区分刺激子成分不同或辐射强度相同的刺激（对照任务），但它们无法区分刺激子成分的电场矢量方向相差90度或偏振角度相同的刺激。鸟类在对照任务中表现成功，但未能完成偏振任务，这表明它们具备做出区分所需的所有认知能力，只是对偏振角度不敏感。我们得出结论，鹌鹑和椋鸟在这项觅食任务中无法利用偏振线索。
