Weary Taylor E, Wrangham Richard W, Clauss Marcus
Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, 02138.
Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Zurich, 8057, Switzerland.
Am J Phys Anthropol. 2017 Jul;163(3):510-518. doi: 10.1002/ajpa.23225. Epub 2017 Apr 4.
Fecal particle size (FPS) as quantified by wet sieving analysis is a measure of chewing efficiency relevant for the understanding of physiological adaptations and constraints in herbivores. FPS has not been investigated systematically in frugivores, and important methodological problems remain. In particular, food items that are not chewed may skew estimates of FPS. We address such methodological issues and also assess the influence of diet type and age on FPS in wild chimpanzees.
About 130 fecal samples of 38 individual chimpanzees (aged from 1.3 to ∼55 years) from the Kanyawara community of Kibale National Park (Uganda) were collected during three fruit seasons and analyzed using standardized wet sieves (pores from 16 to 0.025 mm). The effects of using different sieve series and excluding large seeds were investigated. We also assessed the relationship between FPS and sex, age, and fruit season.
The treatment of seeds during the sieving process had a large influence on the results. FPS was not influenced by chimpanzee sex or age, but was smaller during a fig season (0.88 ± 0.31 mm) than during two drupe-fruit seasons (1.68 ± 0.37 mm) (0.025-4 mm sieves, excluding seeds).
The absence of an age effect on FPS suggests that dental senescence might be less critical in chimpanzees, or in frugivores in general, than in folivorous herbivores. To increase the value of FPS studies for understanding frugivore and hominoid dietary evolution we propose modifications to prior herbivore protocols.
通过湿筛分析法量化的粪便颗粒大小（FPS）是衡量咀嚼效率的指标，有助于理解食草动物的生理适应和限制因素。尚未对食果动物的FPS进行系统研究，且存在重要的方法学问题。特别是，未经咀嚼的食物可能会使FPS的估计产生偏差。我们解决此类方法学问题，并评估饮食类型和年龄对野生黑猩猩FPS的影响。
在三个水果季节收集了乌干达基巴莱国家公园卡尼亚瓦拉社区38只个体黑猩猩（年龄从1.3岁至约55岁）的约130份粪便样本，使用标准化湿筛（孔径从16毫米至0.025毫米）进行分析。研究了使用不同筛网系列和排除大种子的影响。我们还评估了FPS与性别、年龄和水果季节之间的关系。
筛分过程中对种子的处理对结果有很大影响。FPS不受黑猩猩性别或年龄的影响，但在无花果季节（0.88±0.31毫米）比在两个核果季节（1.68±0.37毫米）小（0.025 - 4毫米筛网，排除种子）。
FPS不存在年龄效应表明，与食叶食草动物相比，牙齿衰老在黑猩猩或一般食果动物中可能不那么关键。为了提高FPS研究在理解食果动物和类人猿饮食进化方面的价值，我们建议对先前的食草动物研究方案进行修改。
