School of Biological Sciences, Bristol University, Bristol, UK.
J Exp Biol. 2012 Aug 1;215(Pt 15):2653-9. doi: 10.1242/jeb.071076.
Social groups are structured by the decisions of their members. Social insects typically divide labour: some decide to stay in the nest while others forage for the colony. Two sources of information individuals may use when deciding whether to forage are their own experience of recent task performance and their own physiology, e.g. fat reserves (corpulence). The former is primarily personal information; the latter may give an indication of the food reserves of the whole colony. These factors are hard to separate because typically leaner individuals are also more experienced foragers. We designed an experiment to determine whether foraging specialisation is physiological or experience based (or both). We invented a system of automatic doors controlled by radio-tag information to manipulate task access and decouple these two sources of information. Our results show that when information from corpulence and recent experience conflict, ants behave only in accordance with their corpulence. However, among ants physiologically inclined to forage (less corpulent ants), recent experience of success positively influenced their propensity to forage again. Hence, foraging is organised via long-term physiological differences among individuals resulting in a relatively stable response threshold distribution, with fine-tuning provided by short-term learning processes. Through these simple rules, colonies can organise their foraging effort both robustly and flexibly.
社会群体是由其成员的决策构成的。社会性昆虫通常会分工：一些留在巢穴中，而另一些则为蚁群寻找食物。个体在决定是否觅食时可能会用到两种信息来源，一种是他们自己最近执行任务的经验，另一种是他们自己的生理状况，例如脂肪储备（肥胖程度）。前者主要是个人信息；后者可能表明整个蚁群的食物储备情况。这些因素很难分开，因为通常较瘦的个体经验也更丰富。我们设计了一个实验来确定觅食专业化是基于生理因素还是经验（或两者兼有）。我们发明了一种由无线电标签信息控制的自动门系统，以操纵任务访问并将这两种信息来源分开。我们的结果表明，当肥胖程度和最近经验的信息发生冲突时，蚂蚁只会根据它们的肥胖程度行事。然而，在生理上倾向于觅食的蚂蚁中（肥胖程度较低的蚂蚁），最近成功的经验会积极影响它们再次觅食的倾向。因此，觅食是通过个体之间长期的生理差异来组织的，这导致了一个相对稳定的反应阈值分布，而短期的学习过程则提供了微调。通过这些简单的规则，蚁群可以灵活而稳健地组织它们的觅食工作。
