Antipredator vigilance may be affected by feeding techniques that obstruct animal’s vision, such as underwater foraging. I examined the effect of underwater foraging on head-up position in spring staging dunlins (Calidris alpina), predicting that this type of foraging would positively affect the frequency of head-up vigilance in this species. The results of analysis showed that significant predictors of the occurrence of head-up positions were underwater foraging and head-up position that occurred in the imminent past. Results of this study imply that dunlins are less likely to raise their heads above the shoulder line if they have not obstructed their vision by underwater foraging in the previous moment and that birds are able to acquire visual information from their surroundings not only when their heads are in the upright position but also during head-down foraging and/or during horizontal head position.

中文翻译：

---

水下觅食增加了都林（Calidris alpina）抬头的机会

抗捕食者的警惕性可能会受到阻碍动物视力的进食技术的影响，例如水下觅食。我检查了水下觅食对春季登喜林（Calidris alpina）抬头位置的影响），预测这种觅食方式将对该物种抬头警惕的频率产生积极影响。分析结果表明，抬头位置发生的重要预测因素是水下觅食和即将过去的抬头位置。这项研究的结果表明，如果没有在前一刻在水下觅食而阻碍视线的活动，则鸟林不太可能将头抬高到肩线以上，而且禽类不仅能够从头顶处获得周围环境的视觉信息，在直立位置时，以及在头朝下觅食和/或头部水平时。