Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103 Leipzig, Germany.
Rapid Commun Mass Spectrom. 2012 Jan 15;26(1):69-77. doi: 10.1002/rcm.5312.
A mounting body of evidence suggests that changes in energetic conditions like prolonged starvation can be monitored using stable isotope ratios of tissues such as bone, muscle, hair, and blood. However, it is unclear if urinary stable isotope ratios reflect a variation in energetic condition, especially if these changes in energetic condition are accompanied by shifts in dietary composition. In a feeding experiment conducted on captive bonobos (Pan paniscus), we monitored urinary δ(13)C, δ(15)N, total C (carbon), total N (nitrogen), and C/N ratios and compared these results with glucocorticoid levels under gradually changing energy availability and dietary composition. Measurements of daily collected urine samples over a period of 31 days showed that while shifts in urinary isotope signatures of δ(13)C and δ(15)N as well as total C were best explained by changes in energy consumption, urinary total N excretion as well as the C/N ratios matched the variation in dietary composition. Furthermore, when correcting for fluctuations in dietary composition, the isotope signatures of δ(13)C and δ(15)N as well as total C correlated with urinary glucocorticoid levels; however, the urinary total N and the C/N ratio did not. These results indicate for the first time that it is possible to non-invasively explore specific longitudinal records on animal energetic conditions and dietary compositions with urinary stable isotope ratios and elemental compositions, and this research provides a strong foundation for investigating how ecological factors and social dynamics affect feeding habits in wild animal populations such as primates.
越来越多的证据表明，通过骨骼、肌肉、毛发和血液等组织的稳定同位素比值，可以监测能量条件的变化，如长期饥饿。然而，目前尚不清楚尿液稳定同位素比值是否反映了能量状况的变化，特别是如果这些能量状况的变化伴随着饮食成分的变化。在一项对圈养倭黑猩猩（Pan paniscus）进行的饲养实验中，我们监测了尿液 δ(13)C、δ(15)N、总碳（C）、总氮（N）和 C/N 比值，并将这些结果与逐渐变化的能量供应和饮食组成下的糖皮质激素水平进行了比较。在 31 天的时间里，我们对每天收集的尿液样本进行了测量，结果表明，尽管 δ(13)C 和 δ(15)N 以及总 C 的尿液同位素特征的变化主要由能量消耗的变化来解释，但总 N 的排泄以及 C/N 比值与饮食成分的变化相匹配。此外，当校正饮食成分的波动时，δ(13)C 和 δ(15)N 以及总 C 的同位素特征与尿中糖皮质激素水平相关；然而，总 N 和 C/N 比值则不相关。这些结果首次表明，通过尿液稳定同位素比值和元素组成，有可能非侵入性地探索动物能量状况和饮食成分的特定纵向记录，这项研究为研究生态因素和社会动态如何影响灵长类动物等野生动物种群的觅食习惯提供了坚实的基础。
