How animals respond to seasonal resource availability has profound implications for their dietary flexibility and realized ecological niches. We sought to understand seasonal dietary niche partitioning in extant African suids using intra-tooth stable isotope analysis of enamel. We collected enamel samples from canines of red river hogs/bushpigs (Potamochoerus spp.) and third molars of warthogs (Phacochoerus spp.) in three different regions of central and eastern Africa. We analyzed multiple samples from each tooth and used variations in stable carbon and oxygen isotope ratios (δ13C and δ18O) and covariances between them to infer seasonal dietary changes. We found that most Phacochoerus display C4-dominated diets, while most Potamochoerus display C3-dominated diets. Phacochoerus and Potamochoerus that co-occur in the same region display no overlap in intra-tooth δ13C, which suggests dietary niche partitioning. They also show diverging δ13C values as the dry seasons progress and converging δ13C values during the peak of the rainy seasons, which suggests a greater dietary niche separation during the dry seasons when resources are scarce than during the rainy season. We found statistically significant cross-correlations between intra-tooth δ13C and δ18O in most specimens. We also observed a temporal lag between δ13C and δ18O in some specimens. This study demonstrates that intra-tooth stable isotope analysis is a promising approach to investigate seasonal dietary niche variation. However, large inter-individual variations in δ18O at certain localities can be challenging to interpret. Future studies that expand the intra-tooth stable isotope surveys or include controlled feeding experiments will improve its application in ecological studies.

中文翻译：

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齿内稳定同位素分析揭示了丛林猪/红河猪和疣猪之间的季节性饮食变化和生态位划分

动物如何应对季节性资源可用性对其饮食灵活性和实现的生态位具有深远的影响。我们试图利用牙釉质的牙内稳定同位素分析来了解现存非洲猪的季节性饮食生态位分配。我们从非洲中部和东部三个不同地区的红河猪/灌木猪（Potamochoerus spp.）的犬齿和疣猪（Phacochoerus spp.）的第三磨牙中收集了牙釉质样本。我们分析了每颗牙齿的多个样本，并利用稳定碳和氧同位素比率（δ13C 和 δ18O）的变化以及它们之间的协方差来推断季节性饮食变化。我们发现大多数白鹤属以 C4 为主的饮食，而大多数 Potamochoerus 则以 C3 为主的饮食。在同一区域同时出现的Phacochoerus 和 Potamochoerus 在齿内 δ13C 方面没有重叠，这表明饮食生态位划分。它们还显示，随着旱季的进展，δ13C 值会发散，而在雨季高峰期间，δ13C 值会趋同，这表明在资源稀缺的旱季，膳食生态位分离程度比雨季更大。我们发现大多数标本中齿内 δ13C 和 δ18O 之间存在统计显着的互相关性。我们还在一些样本中观察到 δ13C 和 δ18O 之间存在时间滞后。这项研究表明，牙内稳定同位素分析是研究季节性饮食生态位变化的一种有前途的方法。然而，某些地点 δ18O 个体间的巨大差异可能难以解释。未来扩大牙内稳定同位素调查或包括控制喂养实验的研究将改善其在生态研究中的应用。