Elgart-Berry Alison
Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA.
Am J Primatol. 2004 Apr;62(4):275-85. doi: 10.1002/ajp.20021.
Mountain gorillas, the largest extant primates, subsist almost entirely on plant matter. Moreover, their diet includes a substantial amount of structural material, such as bark and stems, which other primates tend to avoid. Accordingly, the robust masticatory apparatus of gorillas may be adaptive to this presumably tough diet; however, quantitative information on this subject is lacking. In this study the fracture toughness of mountain gorilla foods was examined for the first time. Samples of 44 food plants from Bwindi-Impenetrable National Park (BINP) and Mgahinga Gorilla National Park (MGNP) were tested. These parks are inhabited by two gorilla populations that regarded by some as being distinct at the subspecific taxonomic level. Although food toughness did not differ between the two populations, both diets contained tough items. Tree barks were the toughest food items (varying from 0.23 to 8.2 kJ/m2), followed by shrub barks, pith, and stems. The toughness of leaves and fruit was negligible compared to that of bark. The toughness of bamboo was low in comparison to the toughest food items. Accordingly, the prominent toughness of bark, pith, and stems may be key factors in the evolution of orofacial robusticity in mountain gorillas.
山地大猩猩是现存最大的灵长类动物，几乎完全以植物为食。此外，它们的饮食包括大量的结构物质，如树皮和茎干，而其他灵长类动物往往会避开这些。因此，大猩猩强健的咀嚼器官可能适应了这种据推测很坚韧的饮食；然而，关于这个主题的定量信息却很缺乏。在本研究中，首次对山地大猩猩食物的断裂韧性进行了检测。对来自布温迪难以穿越国家公园（BINP）和马加辛加大猩猩国家公园（MGNP）的44种食用植物样本进行了测试。这两个公园居住着两个大猩猩种群，有些人认为它们在亚种分类水平上是不同的。尽管两个种群的食物韧性没有差异，但两种饮食都包含坚韧的食物。树皮是最坚韧的食物（从0.23到8.2千焦/平方米不等），其次是灌木树皮、髓和茎干。与树皮相比，树叶和果实的韧性可以忽略不计。与最坚韧的食物相比，竹子的韧性较低。因此，树皮、髓和茎干突出的韧性可能是山地大猩猩口腔强健性进化的关键因素。
