Oculomotor strategy of an avian ground forager: tilted and weakly yoked eye saccades
Oculomotor strategy of an avian ground forager: tilted and weakly yoked eye saccades
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鸟类地面觅食者的动眼神经策略：倾斜和弱轭眼扫视
DOI：
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发表时间：
2015
影响因子：
2.8
通讯作者：
E. Fernández‐Juricic
中科院分区：
文献类型：
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作者：
Luke P. Tyrrell;Shannon R Butler;E. Fernández‐Juricic
摘要许多鸟类都能进行大范围的眼球扫视运动，这会导致它们的视线方向发生实质性的变化，并使它们的视野方向发生复杂的变化。在没有视觉刺激的情况下，鸟类会自发地进行眼跳，这是一种内源性的眼动策略。我们使用专门用于小型鸟类的新眼动追踪技术来研究一种开放栖息地，地面觅食的鸣禽，欧洲椋鸟（Sturnus vulgaris）的眼动行为。我们发现，椋鸟主要是沿着沿着一个倾斜的轴向前向下和向后向上13.46度，这与其他物种采用的平行于地平线的轴不同。当椋鸟低头寻找食物时，这种倾斜的轴可以增强觅食和反捕食者的策略，使它们能够直接观察张开的下颌骨之间的食物，并在头部上方和后方扫描捕食者更有可能攻击的区域。我们还发现，椋鸟既没有完全共轭的扫视（例如人类），也没有独立的扫视（例如变色龙）。相反，他们表现出微弱的轭式扫视，其中左眼和右眼同时移动，但幅度不同。在功能上，弱轭式眼跳可能类似于独立眼跳，因为它们允许两只眼睛同时执行不同的任务。研究物种的眼动策略之间的差异表明，眼睛运动在不同生态位的鸟类中发挥着不同但重要的作用。摘要：欧洲椋鸟采用独特的视觉策略，以满足在开放栖息地觅食和躲避捕食者的视觉需求。
ABSTRACT Many bird species are capable of large saccadic eye movements that can result in substantial shifts in gaze direction and complex changes to their visual field orientation. In the absence of visual stimuli, birds make spontaneous saccades that follow an endogenous oculomotor strategy. We used new eye-tracking technology specialized for small birds to study the oculomotor behavior of an open-habitat, ground-foraging songbird, the European starling (Sturnus vulgaris). We found that starlings primarily move their eyes along a tilted axis 13.46 deg downwards anteriorly and upwards posteriorly, which differs from the axis parallel to the horizon employed by other species. This tilted axis could enhance foraging and anti-predator strategies while starlings are head-down looking for food, allowing them to direct vision between the open mandibles to visually inspect food items, and above and behind the head to scan areas where predators are more likely to attack. We also found that starlings have neither fully conjugate saccades (as in humans, for example) nor independent saccades (as in chameleons, for example). Rather, they exhibit weakly yoked saccades where the left and right eyes move at the same time but not at the same magnitude. Functionally, weakly yoked saccades may be similar to independent saccades in that they allow the two eyes to concomitantly perform different tasks. The differences between the oculomotor strategies of studied species suggest eye movements play variable but important roles across bird species with different ecological niches. Summary: European starlings employ a unique oculomotor strategy that meets the visual demands of foraging and avoiding predators in open habitats.