Lewis Matthew C, West Adam G, O'Riain M Justin
Department of Biological Sciences, University of Cape Town, Rondebosch, 7701, South Africa.
Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Rondebosch, 7701, South Africa.
Am J Phys Anthropol. 2018 Jan;165(1):77-93. doi: 10.1002/ajpa.23332. Epub 2017 Oct 27.
Stable isotope analysis has been used to investigate consumption of marine resources in a variety of terrestrial mammals, including humans, but not yet in extant nonhuman primates. We sought to test the efficacy of stable isotope analysis as a tool for such studies by comparing isotope- and observation-based estimates of marine food consumption by a troop of noncommensal, free-ranging chacma baboons.
We determined δ C and δ N values of baboon hair (n = 9) and fecal samples (n = 144), and principal food items (n = 362). These values were used as input for diet models, the outputs of which were compared to observation-based estimates of marine food consumption.
Fecal δ C values ranged from -29.3‰ to -25.6‰. δ N values ranged from 0.9‰ to 6.3‰ and were positively correlated with a measure of marine foraging during the dietary integration period. Mean (± SD) δ C values of adult male and female baboon hairs were -21.6‰ (± 0.1) and -21.8‰ (± 0.3) respectively, and corresponding δ N values were 5.0‰ (± 0.3) and 3.9‰ (± 0.2). Models indicated that marine contributions were ≤10% of baboon diet within any season, and contributed ≤17% of dietary protein through the year.
Model output and observational data were in agreement, both indicating that despite their abundance in the intertidal region, marine foods comprised only a small proportion of baboon diet. This suggests that stable isotope analysis is a viable tool for investigating marine food consumption by natural-foraging primates in temperate regions.
稳定同位素分析已被用于研究包括人类在内的多种陆生哺乳动物对海洋资源的消耗情况，但尚未应用于现存的非人灵长类动物。我们试图通过比较一群非共生、自由放养的东非狒狒基于同位素和观察的海洋食物消耗估计值，来测试稳定同位素分析作为此类研究工具的有效性。
我们测定了狒狒毛发（n = 9）、粪便样本（n = 144）以及主要食物项目（n = 362）的δC和δN值。这些值被用作饮食模型的输入，模型输出结果与基于观察的海洋食物消耗估计值进行比较。
粪便δC值范围为-29.3‰至-25.6‰。δN值范围为0.9‰至6.3‰，并且与饮食整合期内的海洋觅食量呈正相关。成年雄性和雌性狒狒毛发的平均（±标准差）δC值分别为-21.6‰（±0.1）和-21.8‰（±0.3），相应的δN值分别为5.0‰（±0.3）和3.9‰（±0.2）。模型表明，在任何季节，海洋食物对狒狒饮食的贡献≤10%，全年对饮食蛋白质的贡献≤17%。
模型输出结果与观测数据一致，两者均表明尽管潮间带区域海洋食物丰富，但在狒狒的饮食中仅占一小部分。这表明稳定同位素分析是研究温带地区自然觅食灵长类动物海洋食物消耗情况的可行工具。
