Yorzinski Jessica L, Platt Michael L
Duke Institute for Brain Sciences, Center for Cognitive Neuroscience, Duke University, Durham, NC, 27710, USA,
Anim Cogn. 2014 May;17(3):767-77. doi: 10.1007/s10071-013-0708-x. Epub 2013 Nov 20.
Predation can exert strong selective pressure on the evolution of behavioral and morphological traits in birds. Because predator avoidance is key to survival and birds rely heavily on visual perception, predation may have shaped avian visual systems as well. To address this question, we examined the role of visual attention in antipredator behavior in peacocks (Pavo cristatus). Peacocks were exposed to a model predator while their gaze was continuously recorded with a telemetric eye-tracker. We found that peacocks spent more time looking at and made more fixations on the predator compared to the same spatial location before the predator was revealed. The duration of fixations they directed toward conspecifics and environmental features decreased after the predator was revealed, indicating that the peacocks were rapidly scanning their environment with their eyes. Maximum eye movement amplitudes and amplitudes of consecutive saccades were similar before and after the predator was revealed. In cases where conspecifics detected the predator first, peacocks appeared to learn that danger was present by observing conspecifics' antipredator behavior. Peacocks were faster to detect the predator when they were fixating closer to the area where the predator would eventually appear. In addition, pupil size increased after predator exposure, consistent with increased physiological arousal. These findings demonstrate that peacocks selectively direct their attention toward predatory threats and suggest that predation has influenced the evolution of visual orienting systems.
捕食行为会对鸟类行为和形态特征的进化施加强大的选择压力。由于躲避捕食者是生存的关键,且鸟类严重依赖视觉感知,捕食行为可能也塑造了鸟类的视觉系统。为了解决这个问题,我们研究了视觉注意力在孔雀(孔雀雉)反捕食行为中的作用。在使用遥测式眼动仪持续记录孔雀目光的同时,让它们接触一个捕食者模型。我们发现,与捕食者出现前相同的空间位置相比,孔雀会花更多时间注视捕食者,且有更多的注视点。在捕食者出现后,它们注视同种个体和环境特征的持续时间减少,这表明孔雀正在用眼睛快速扫视周围环境。捕食者出现前后,最大眼动幅度和连续扫视幅度相似。在同种个体先检测到捕食者的情况下,孔雀似乎通过观察同种个体的反捕食行为得知危险存在。当孔雀注视点更靠近捕食者最终出现的区域时,它们能更快地发现捕食者。此外,暴露于捕食者后瞳孔大小增加,这与生理唤醒增强一致。这些发现表明,孔雀会选择性地将注意力导向捕食威胁,并表明捕食行为影响了视觉定向系统的进化。