The visual fields of Common Guillemots Uria aalge and Atlantic Puffins Fratercula arctica: foraging, vigilance and collision vulnerability
The visual fields of Common Guillemots Uria aalge and Atlantic Puffins Fratercula arctica: foraging, vigilance and collision vulnerability
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普通海鸠 Uria aalge 和大西洋海鹦 Fratercula arctica 的视野：觅食、警惕性和碰撞脆弱性
作者：
G. Martin;S. Wanless
在觅食技术不同的密切相关物种之间发现鸟类视野存在显着差异。我们报告了两种海雀的视野存在显着差异。在空气中，海鸠具有相对狭窄的双眼视野，这是非雀形目掠食性鸟类的典型特征。大西洋海雀 Fratercula arctica 拥有更广阔的双眼视场，类似于迄今为止在雀形目鸟类和企鹅身上记录到的视场。在水中，两种海雀的视野都相当狭窄，并且朝向喙方向的双眼视觉可能都被消除了。尽管这两个物种在繁殖季节与觅食相关的感知挑战相似，但当它们是鱼食性时，海雀（但不是海鸠）在其他时间觅食时面临着更严格的感知挑战，因为它们会捕食大量的小型无脊椎动物猎物。捕获这种猎物可能需要更准确、视觉引导的喙放置，我们认为海雀更宽的双目视野可以满足这一要求，该视野在浸入水中时得以保留；它向上的方向可以使猎物的轮廓清晰可见。这些视野配置具有潜在的重要后果，使这些鸟类在水下很容易与人类制品发生碰撞，但在空中则不然。它们也会对警惕行为产生影响。
Significant differences in avian visual fields are found between closely related species that differ in their foraging technique. We report marked differences in the visual fields of two auk species. In air, Common Guillemots Uria aalge have relatively narrow binocular fields typical of those found in non-passerine predatory birds. Atlantic Puffins Fratercula arctica have much broader binocular fields similar to those that have hitherto been recorded in passerines and in a penguin. In water, visual fields narrow considerably and binocularity in the direction of the bill is probably abolished in both auk species. Although perceptual challenges associated with foraging are similar in both species during the breeding season, when they are piscivorous, Puffins (but not Guillemots) face more exacting perceptual challenges when foraging at other times, when they take a high proportion of small invertebrate prey. Capturing this prey probably requires more accurate, visually guided bill placement and we argue that this is met by the Puffin's broader binocular field, which is retained upon immersion; its upward orientation may enable prey to be seen in silhouette. These visual field configurations have potentially important consequences that render these birds vulnerable to collision with human artefacts underwater, but not in air. They also have consequences for vigilance behaviour.