Closed-canopy rainforests are important for climate (influencing atmospheric circulation, albedo, carbon storage, etc.) and ecology (harboring the highest biodiversity of continental regions). Of all rainforests, Amazonia is the world’s most diverse, including the highest mammalian species richness. However, little is known about niche structure, ecological roles, and food resource partitioning of Amazonian mammalian communities over time. Through analyses of δ¹³C_bioapatite, δ¹³C_hair, and δ¹⁵N_hair, we isotopically characterized aspects of feeding ecology in a modern western Amazonian mammalian community in Peru, serving as a baseline for understanding the evolution of Neotropical rainforest ecosystems. By comparing these results with data from equatorial Africa, we evaluated the potential influences of distinct phylogenetic and biogeographic histories on the isotopic niches occupied by mammals in analogous tropical ecosystems. Our results indicate that, despite their geographical and taxonomic differences, median δ¹³C_diet values from closed-canopy rainforests in Amazonia (−27.4‰) and equatorial Africa (−26.9‰) are not significantly different, and that the median δ¹³C_diet expected for mammalian herbivores in any closed-canopy rainforest is −27.2‰. Amazonian mammals seem to exploit a narrower spectrum of dietary resources than equatorial African mammals, however, as depicted by the absence of highly negative δ¹³C_diet values previously proposed as indicative of rainforests (<−31‰). Finally, results of keratin and bioapatite δ¹³C indicate that the predictive power of trophic relationships, and traditional dietary ecological classifications in bioapatite-protein isotopic offset expectations, must be reconsidered.

封闭式雨林对气候（影响大气环流，反照率，碳存储等）和生态学（具有大陆地区最高的生物多样性）至关重要。在所有的雨林中，亚马逊是世界上种类最多的，包括哺乳动物物种丰富度最高的地区。但是，随着时间的推移，人们对亚马逊哺乳动物社区的生态位结构，生态作用和食物资源分配知之甚少。通过δ的分析¹³ Ç _bioapatite，δ ¹³ Ç_毛发，和δ ¹⁵ Ñ_发，我们对秘鲁现代亚马逊河西部哺乳动物群落的摄食生态学进行了同位素表征，以此作为了解新热带雨林生态系统演变的基准。通过将这些结果与来自赤道非洲的数据进行比较，我们评估了不同的系统发生史和生物地理史对哺乳动物在类似热带生态系统中占据的同位素生态位的潜在影响。我们的研究结果表明，尽管它们的地理和分类学的差异，平均δ ¹³ C ^_饮食从封闭树冠雨林值亚马逊（-27.4‰）和赤道非洲（-26.9‰）不显著不同，而平均δ ¹³ C ^_饮食在任何封闭式雨林中，预计哺乳动物食草动物为-27.2‰。亚马逊哺乳动物似乎利用膳食资源的比赤道非洲哺乳动物较窄频谱，然而，通过不存在高度负δ的如所描绘的¹³ Ç_饮食值先前提出的作为表示雨林（<-31‰）。最后，角蛋白和bioapatiteδ结果¹³ C为的是营养的关系，并在bioapatite蛋白饮食传统生态分类的预测能力同位素偏移的期望，必须重新考虑。