Moscovice L R, Issa M H, Petrzelkova K J, Keuler N S, Snowdon C T, Huffman M A
Biology Department, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6018, USA.
Am J Primatol. 2007 May;69(5):487-502. doi: 10.1002/ajp.20350.
We examined seasonal patterns of fruit availability, dietary quality, and group size in the descendants of an introduced chimpanzee population on Rubondo Island, Tanzania. The site has supported a free-ranging population without provisioning for 40 years. Our goals were to determine whether Rubondo chimpanzees experience periods of fruit shortage, and whether they respond to changes in fruit availability similarly to chimpanzees at endemic sites. We indexed the fruit availability of tree and liana species on transects stratified across three chimpanzee ranging areas. We used fecal analyses to evaluate seasonal changes in diet, and used data on party size and nesting group size to examine seasonal patterns of grouping. Tree fruit availability was positively correlated with rainfall, with a period of relative tree fruit scarcity corresponding with the long dry season. Liana fruit availability was not related to rainfall, and lianas exhibited less variable fruiting patterns across seasons. Fruits made up the majority of the chimpanzee diet, with lianas accounting for 35% of dietary fruit species. Fruits of the liana Saba comorensis were available during all months of phenological monitoring, but they were consumed more when tree fruit was scarce, suggesting that Saba comorensis fruits may be a fallback food for Rubondo chimpanzees. There were no increases in consumption of lower-quality plant parts between seasons, and there were no changes in group size between seasons. These results contrast with evidence from several endemic chimpanzee study sites, and indicate that Rubondo chimpanzees may have access to abundant and high-quality foods year round.
我们研究了坦桑尼亚鲁邦多岛一个引进的黑猩猩种群后代的水果可获得性、饮食质量和群体规模的季节性模式。该地点在没有人工投喂的情况下维持自由放养的黑猩猩种群已有40年。我们的目标是确定鲁邦多岛的黑猩猩是否经历水果短缺期，以及它们对水果可获得性变化的反应是否与原生地的黑猩猩相似。我们在横跨三个黑猩猩活动区域分层设置的样带上，对树木和藤本植物物种的水果可获得性进行了索引。我们通过粪便分析评估饮食的季节性变化，并利用群体规模和筑巢群体规模的数据来研究群体的季节性模式。树木果实的可获得性与降雨量呈正相关，在漫长的旱季相对应的时期树木果实较为稀缺。藤本植物果实的可获得性与降雨量无关，并且藤本植物在不同季节的结果模式变化较小。水果在黑猩猩的饮食中占大部分，藤本植物占饮食中水果种类的35%。在物候监测的所有月份都有藤本植物萨巴 comorensis 的果实，但在树木果实稀缺时它们的消耗量更大，这表明萨巴 comorensis 的果实可能是鲁邦多岛黑猩猩的替代食物。不同季节之间低质量植物部分的消耗量没有增加，群体规模也没有变化。这些结果与几个原生黑猩猩研究地点的证据形成对比，表明鲁邦多岛的黑猩猩可能全年都能获得丰富且高质量的食物。
