Long-tailed macaques select mass of stone tools according to food type
Long-tailed macaques select mass of stone tools according to food type
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DOI：
10.1098/rstb.2012.0413
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发表时间：
2013-11-19
影响因子：
6.3
通讯作者：
Malaivijitnond, Suchinda
中科院分区：
文献类型：
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作者：
Gumert, Michael D.;Malaivijitnond, Suchinda
工具的选择可以影响基于工具的喂养任务的成功，因此使用工具的动物在加工食物时应该选择适当的工具。我们在泰国莱姆逊国家公园的Piak Namyai岛上进行了一项野外实验，以测试缅甸长尾猕猴(Macaca Fascularis Aurea)是否根据食物类型选择石器。为了吸引猕猴使用准实验设计的石头，我们在岛上的海岸上放置了成套的石块(工具测试)。在两年的时间里，在344个地点进行了为期126天的工具测试，每组包含四种不同质量的石头(类别：X，40-60g；S，90-100g；M，150-200g；L，400-1000g)。工具测试是在我们可以访问它们时进行检查的。每次工具测试的检查次数各不相同(1-32次)，总共检查1950次。我们还研究了在自然发生的工具使用地点发现的375件非试验性石器。我们的数据不是通过直接观察收集的，而是通过使用后检查石头来收集的。我们发现石块质量和食物类型之间存在关联。在工具测试中，我们发现S石最常用于附着的牡蛎，L石最常用于未附着的食物。L结石几乎总是用于较大的独立食物(大于3厘米长)，而对于较小的独立食物(小于或等于3厘米长)，选择偏向L结石较少，在M和L结石类别之间分布更均匀。在非实验研究中，我们发现体重在五种食物类别(范围：16-5166克)之间存在显著差异。与之前的研究相比，我们揭示了关于猕猴石器质量的更多细节，表明猕猴在各种工具加工的食物中选择不同的石块。我们的研究是研究猕猴在工具选择过程中使用的行为和认知机制的第一步。
Tool selection can affect the success of a tool-based feeding task, and thus tool-using animals should select appropriate tools when processing foods. We performed a field experiment on Piak Nam Yai Island in Laem Son National Park, Thailand, to test whether Burmese long-tailed macaques (Macaca fascicularis aurea) selected stone tools according to food type. We baited the island's shores with stone sets ('tool tests') in an effort to attract macaques to use stones presented in a quasi-experimental design. Tool tests were placed at 344 locations for 126 days over a 2 year period, with each set containing four stones of different mass (categories: X, 40-60 g; S, 90-100 g; M, 150-200 g; and L, 400-1000 g). Tool tests were checked when we could access them. The number of times each tool test was checked varied (1-32), for a total of 1950 checks. We also studied 375 non-experimental stone tools that were found at naturally occurring tool-use sites. Our data were not collected by direct observation, but by inspecting stones after use. We found an association between stone mass and food type. In the tool tests, we found S-stones were chosen most often for attached oysters, and L-stones were chosen most often for unattached foods. L-stones were almost always chosen for larger unattached foods (greater than 3 cm length), while for smaller unattached foods (less than or equal to 3 cm length) selection was less skewed to L-stones and more evenly distributed between the M-and L-stone categories. In the non-experimental study, we found that mass varied significantly across five food categories (range: 16-5166 g). We reveal more detail on macaque stone tool mass than previous studies, showing that macaques select differing stone masses across a variety of tool-processed foods. Our study is the first step in investigating the behavioural and cognitive mechanisms that macaques are using during tool selection.