Nocturnal animals that rely on their visual system for foraging, mating, and navigation usually exhibit specific traits associated with living in scotopic conditions. Most nocturnal birds have several visual specializations, such as enlarged eyes and an increased orbital convergence. However, the actual role of binocular vision in nocturnal foraging is still debated. Nightjars (Aves: Caprimulgidae) are predators that actively pursue and capture flying insects in crepuscular and nocturnal environments, mainly using a conspicuous "sit-and-wait" tactic on which pursuit begins with an insect flying over the bird that sits on the ground. In this study, we describe the visual system of the band-winged nightjar (Systellura longirostris), with emphasis on anatomical features previously described as relevant for nocturnal birds. Orbit convergence, determined by 3D scanning of the skull, was 73.28°. The visual field, determined by ophthalmoscopic reflex, exhibits an area of maximum binocular overlap of 42°, and it is dorsally oriented. The eyes showed a nocturnal-like normalized corneal aperture/axial length index. Retinal ganglion cells (RGCs) were relatively scant, and distributed in an unusual oblique-band pattern, with higher concentrations in the ventrotemporal quadrant. Together, these results indicate that the band-winged nightjar exhibits a retinal specialization associated with the binocular area of their dorsal visual field, a relevant area for pursuit triggering and prey attacks. The RGC distribution observed is unusual among birds, but similar to that of some visually dependent insectivorous bats, suggesting that those features might be convergent in relation to feeding strategies.

中文翻译：

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与夜蛾食虫鸟类带翅夜鹰的视觉系统中觅食有关的解剖学专业知识（Aves：Caprimulgiformes）。

依靠视觉系统觅食，交配和航行的夜行动物通常表现出与暗视条件下生活相关的特定特征。大多数夜间活动的鸟类都有几种视觉专长，例如眼睛扩大和眼眶收敛增加。然而，双眼视觉在夜间觅食中的实际作用仍存在争议。Nightjars（Aves：Caprimulgidae）是捕食者，它们在夜行和夜间环境中主动追捕和捕获飞行中的昆虫，主要是采用明显的“坐等”策略，在这种策略中，追捕始于昆虫在地面上飞过的昆虫。在这项研究中，我们描述了带翅夜鹰（Systellura longirostris）的视觉系统，着重于先前描述为与夜间鸟类相关的解剖特征。轨道收敛 通过颅骨的3D扫描确定的角度为73.28°。通过检眼镜镜反射确定的视野显示出最大双眼重叠区域为42°，并且其背向取向。眼睛表现出夜间样标准化的角膜孔径/轴向长度指数。视网膜神经节细胞（RGCs）相对较少，并以不寻常的斜带模式分布，在腹颞象限中浓度较高。总之，这些结果表明，带翅膀的夜鹰具有与视网膜背视的双目区域相关的视网膜专长，该区域是追击触发和猎物攻击的相关区域。观察到的RGC分布在鸟类中并不常见，但与某些视觉依赖的食虫蝙蝠相似，