The role of light in partitioning ecological niche space remains a frontier in understanding the assembly of terrestrial vertebrate communities and their response to global change. Leveraging recent advances in biologging technology and intensive field surveys of cloud forest bird communities across an agricultural land use gradient in the Peruvian Andes, we demonstrate that eye size predicts (a) the ambient light microenvironment used by free-ranging birds, (b) their foraging niche, and (c) species-specific sensitivity to agricultural land use change. For 15 species carrying light sensors (N = 71 individuals), light-intensity levels were best explained by eye size and foraging behavior, with larger-eyed species using darker microenvironments. Across the cloud forest bird community (N = 240 species), hyperopic ("far-sighted") foragers, (e.g., flycatchers), had larger eyes compared to myopic ("near-sighted") species (e.g., gleaners and frugivores); eye size was also larger for myopic insectivores that foraged in the forest understory. Eye size strongly predicted sensitivity to brightly lit habitats across an agricultural land use gradient. Species that increased in abundance in mixed intensity agriculture, including fencerows, silvopasture, and pasture, had smaller eyes, suggesting that light acts as an environmental filter when communities disassemble in a human-disturbed landscape. We suggest that eye size represents a novel functional trait contributing to terrestrial vertebrate community assembly and sensitivity to habitat disturbance.

中文翻译：

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对光的适应预测热带乡村鸟类群落的觅食生态位和分解

光在划分生态位空间中的作用仍然是了解陆生脊椎动物群落的组装及其对全球变化的反应的前沿。利用生物记录技术的最新进展和对秘鲁安第斯山脉农业用地梯度上云雾林鸟类群落的密集实地调查，我们证明眼睛大小可以预测（a）自由放养鸟类使用的环境光微环境，（b）它们的觅食生态位，以及 (c) 对农业用地变化的物种特异性敏感性。对于携带光传感器的 15 个物种（N = 71 个个体），光强度水平最好用眼睛大小和觅食行为来解释，大眼睛物种使用较暗的微环境。跨越云林鸟类群落（N = 240 种），远视（“远视”）觅食者，（例如，捕蝇器），与近视（“近视”）物种（例如，拾荒者和食果动物）相比具有更大的眼睛；对于在林下层觅食的近视食虫动物，眼睛的尺寸也更大。眼睛大小强烈预测了对跨农业用地梯度的明亮栖息地的敏感性。在混合强度农业中大量增加的物种，包括篱笆、林场和牧场，它们的眼睛较小，这表明当社区在人为干扰的景观中解体时，光充当了环境过滤器。我们认为眼睛大小代表了一种有助于陆生脊椎动物群落组装和对栖息地干扰的敏感性的新功能特征。对于在林下层觅食的近视食虫动物，眼睛的尺寸也更大。眼睛大小强烈预测了对跨农业用地梯度的明亮栖息地的敏感性。在混合强度农业中大量增加的物种，包括篱笆、林场和牧场，它们的眼睛较小，这表明当社区在人为干扰的景观中解体时，光充当了环境过滤器。我们认为眼睛大小代表了一种有助于陆生脊椎动物群落组装和对栖息地干扰的敏感性的新功能特征。对于在林下层觅食的近视食虫动物，眼睛的尺寸也更大。眼睛大小强烈预测了对跨农业用地梯度的明亮栖息地的敏感性。在混合强度农业中大量增加的物种，包括篱笆、林场和牧场，它们的眼睛较小，这表明当社区在人为干扰的景观中解体时，光充当了环境过滤器。我们认为眼睛大小代表了一种有助于陆生脊椎动物群落组装和对栖息地干扰的敏感性的新功能特征。包括篱笆、林场和牧场在内的动物的眼睛较小，这表明当社区在人为干扰的景观中解体时，光线充当了环境过滤器。我们认为眼睛大小代表了一种有助于陆生脊椎动物群落组装和对栖息地干扰的敏感性的新功能特征。包括篱笆、林场和牧场在内的动物的眼睛较小，这表明当社区在人为干扰的景观中解体时，光线充当了环境过滤器。我们认为眼睛大小代表了一种有助于陆生脊椎动物群落组装和对栖息地干扰的敏感性的新功能特征。