Traff Jordan N, McGraw W Scott, Daegling David J
Department of Anthropology, University of Florida, Gainesville, FL, 32611-7305, USA.
Department of Anthropology, The Ohio State University, Columbus, OH, USA.
Primates. 2022 May;63(3):271-282. doi: 10.1007/s10329-022-00978-2. Epub 2022 Apr 1.
The olive colobus (Procolobus verus) is the smallest extant colobine. Based on the axiom that folivory is associated with larger body mass, the olive colobus is expected to be less folivorous than its sister taxon Piliocolobus badius, but previous studies show that the opposite is true. Here we test the hypothesis that masticatory and ingestive effort in the olive colobus is greater due to allometric factors related to bite force scaling and throughput of ingested foods. We analyzed oral processing data collected on olive colobus in the Taï Forest, Ivory Coast, between May 2016 and May 2018. We compare these with previously published data on P. badius and Colobus polykomos from Taï. In terms of overall feeding effort, olive colobus invest more effort (i.e., chewing cycles) than the larger colobines. When contrasts are restricted to commonly consumed foods, this greater energetic investment is not consistently observed. Ingestion of young leaves is associated with a reduced number of masticatory cycles in all three colobine species. A slightly elevated average effort in the olive colobus during young leaf feeding suggests this food source is more challenging in smaller monkeys, but mature leaf processing effort is generally the same among Taï colobines. Thus, for olive colobus, leaf ductility may be more problematic than leaf toughness in terms of masticatory effort. While there may be an allometric cost to being a small colobine, food selectivity is an important mitigating factor.
橄榄疣猴（Procolobus verus）是现存最小的疣猴亚科动物。基于食叶习性与更大体型相关这一公理，预计橄榄疣猴的食叶性比其姐妹分类单元红疣猴（Piliocolobus badius）要低，但先前的研究表明情况恰恰相反。在此，我们检验这样一个假设：由于与咬合力缩放和摄入食物通量相关的异速生长因素，橄榄疣猴的咀嚼和摄食努力更大。我们分析了2016年5月至2018年5月在科特迪瓦伊塔伊森林收集的橄榄疣猴的口腔处理数据。我们将这些数据与之前发表的关于塔伊地区红疣猴和黑疣猴（Colobus polykomos）的数据进行比较。就总体摄食努力而言，橄榄疣猴比体型更大的疣猴投入了更多努力（即咀嚼周期）。当对比仅限于常见的食用食物时，并未始终观察到这种更大的能量投入。在所有三种疣猴中，摄入嫩叶都与咀嚼周期数量减少有关。橄榄疣猴在摄食嫩叶时平均努力略有增加，这表明这种食物来源对体型较小的猴子来说更具挑战性，但在塔伊疣猴中，处理成熟叶片的努力通常是相同的。因此，对于橄榄疣猴来说，就咀嚼努力而言，叶片的延展性可能比韧性更成问题。虽然作为小型疣猴可能存在异速生长成本，但食物选择性是一个重要的缓解因素。
