Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907 USA.
AG Systematik und Evolutionsbiologie. IBU-Fakultät V, Carl von Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany.
Sci Rep. 2017 Jan 12;7:38406. doi: 10.1038/srep38406.
Animals move their heads and eyes to compensate for movements of the body and background, search, fixate, and track objects visually. Avian saccadic head/eye movements have been shown to vary considerably between species. We tested the hypothesis that the configuration of the retina (i.e., changes in retinal ganglion cell density from the retinal periphery to the center of acute vision-fovea) would account for the inter-specific variation in avian head/eye movement behavior. We characterized retinal configuration, head movement rate, and degree of eye movement of 29 bird species with a single fovea, controlling for the effects of phylogenetic relatedness. First, we found the avian fovea is off the retinal center towards the dorso-temporal region of the retina. Second, species with a more pronounced rate of change in ganglion cell density across the retina generally showed a higher degree of eye movement and higher head movement rate likely because a smaller retinal area with relatively high visual acuity leads to greater need to move the head/eye to align this area that contains the fovea with objects of interest. Our findings have implications for anti-predator behavior, as many predator-prey interaction models assume that the sensory system of prey (and hence their behavior) varies little between species.
动物通过头部和眼部运动来补偿身体和背景的运动，从而进行搜索、注视和跟踪视觉物体。已经证明，鸟类的眼球跳动头部/眼部运动在不同物种之间有很大差异。我们检验了这样一个假设，即视网膜的配置（即，从视网膜边缘到急性视觉中心-中央凹的视网膜神经节细胞密度的变化）将解释鸟类头部/眼部运动行为的种间变化。我们通过控制系统发育相关性的影响，对 29 种具有单个中央凹的鸟类的视网膜配置、头部运动速度和眼球运动程度进行了描述。首先，我们发现鸟类的中央凹偏离了视网膜中心，而是位于视网膜的背侧-颞侧区域。其次，视网膜上神经节细胞密度变化率较大的物种通常表现出更高的眼球运动和更高的头部运动速度，这可能是因为相对高的视觉敏锐度的视网膜区域较小，需要更大程度地移动头部/眼睛，以将包含中央凹的这个区域与感兴趣的物体对齐。我们的研究结果对反捕食者行为具有重要意义，因为许多捕食者-猎物相互作用模型假设猎物的感觉系统（因此它们的行为）在物种之间变化很小。
