Hunt Gavin R, Gray Russell D
Department of Psychology, University of Auckland, Private Bag 92019 Auckland, New Zealand.
Biol Lett. 2007 Apr 22;3(2):173-5. doi: 10.1098/rsbl.2006.0603.
Individual specialization in the use of foraging tools occurs in hunter-gatherer societies but is absent in non-human primate tool use. 'Parallel tool industries' in hunter-gatherers are mainly based on strict sexual division of labour that is highly reliant on social conformity. Here, we show that 12 individuals in a population of New Caledonian crows on Maré Island had strong preferences for either stick tools or pandanus tools. Eight of the 12 crows had exclusive preferences. The individual specialization that we found is probably associated with different foraging niches. However, in spite of sexual size dimorphism there was no significant association between the sex of crows and their tool preferences. Our findings demonstrate that highly organized, strict sexual division of labour is not a necessary prerequisite for the evolution of parallel tool industries.
在狩猎采集社会中,觅食工具的使用存在个体专业化现象,但在非人类灵长类动物的工具使用中则不存在。狩猎采集者的“平行工具产业”主要基于高度依赖社会一致性的严格性别分工。在此,我们表明,马雷岛上新喀里多尼亚乌鸦种群中的12只个体对树枝工具或露兜树工具具有强烈偏好。这12只乌鸦中有8只具有排他性偏好。我们发现的个体专业化可能与不同的觅食生态位有关。然而,尽管存在性别体型差异,但乌鸦的性别与其工具偏好之间没有显著关联。我们的研究结果表明,高度组织化、严格的性别分工并非平行工具产业进化的必要前提。