Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
Anim Cogn. 2012 Jan;15(1):83-96. doi: 10.1007/s10071-011-0435-0. Epub 2011 Jul 21.
Previous research has shown that a considerable number of primates can remember the location and fruiting state of individual trees in their home range. This enables them to relocate fruit or predict whether previously encountered fruit has ripened. Recent studies, however, suggest that the ability of primates to cognitively map fruit-bearing trees is limited. In this study, we investigated an alternative and arguably simpler, more efficient strategy, the use of synchrony, a botanical characteristic of a large number of fruit species. Synchronous fruiting would allow the prediction of the fruiting state of a large number of trees without having to first check the trees. We studied whether rainforest primates, grey-cheeked mangabeys in the Kibale National Park, Uganda, used synchrony in fruit emergence to find fruit. We analysed the movements of adult males towards Uvariopsis congensis food trees, a strongly synchronous fruiting species with different local patterns of synchrony. Monkeys approached within crown distance, entered and inspected significantly more Uvariopsis trees when the percentage of trees with ripe fruit was high compared to when it was low. Since the effect was also found for empty trees, the monkeys likely followed a synchrony-based inspection strategy. We found no indication that the monkeys generalised this strategy to all Uvariopsis trees within their home range. Instead, they attended to fruiting peaks in local areas within the home range and adjusted their inspective behaviour accordingly revealing that non-human primates use botanical knowledge in a flexible way.
先前的研究表明，相当数量的灵长类动物能够记住其栖息地范围内个体树木的位置和结果状态。这使它们能够重新找到果实，或者预测先前遇到的果实是否已经成熟。然而，最近的研究表明，灵长类动物认知映射结果树木的能力是有限的。在这项研究中，我们研究了一种替代方法，这种方法可以说是更简单、更有效的策略，即利用同步性，这是许多果实物种的一种植物学特征。同步结果可以在不必首先检查树木的情况下，预测大量树木的结果状态。我们研究了乌干达基巴莱国家公园的灰脸长尾猴等雨林灵长类动物是否会利用果实出现的同步性来寻找果实。我们分析了成年雄性猴子对 Uvariopsis congensis 食物树的运动情况，这是一种具有不同局部同步模式的强烈同步结果物种。当有成熟果实的树木比例较高时，猴子会在树冠距离内接近，并进入和检查更多的 Uvariopsis 树，而当果实比例较低时，这种情况则明显较少。由于这种效果也适用于空树，因此猴子可能会遵循基于同步性的检查策略。我们没有发现猴子将这种策略推广到其栖息地范围内的所有 Uvariopsis 树的迹象。相反，它们会关注栖息地范围内局部地区的结果高峰期，并相应地调整其检查行为，这表明非人类灵长类动物以灵活的方式利用植物学知识。
