Dussutour Audrey, Deneubourg Jean-Louis, Fourcassié Vincent
Centre de Recherches sur la Cognition Animale, UMR CNRS 5169, Université Paul Sabatier, 118 route de Narbonne, F-31062, Toulouse Cedex 4, France.
J Exp Biol. 2005 Aug;208(Pt 15):2903-12. doi: 10.1242/jeb.01711.
Foraging in ants is generally organized along well-defined trails supporting a bi-directional flow of outbound and nestbound individuals and one can hypothesize that this flow is maximized to ensure a high rate of food return to the nest. In this paper we examine the effect of bottlenecks on the temporal organization of ant flow. In our experiments ants had to cross a bridge to go from their nest to a food source. Two types of bridges were used: one with and one without bottlenecks. Traffic counts show that, in spite of the bottlenecks and the reduction of path width, the volume of traffic and the rate of food return were the same on both bridges. This was due to a change in the temporal organization of the flow: when path width decreases alternating clusters of inbound and outbound ants were observed crossing the bridge. This organization limits the number of head-on encounters and thus allows to maintain the same travel duration as on the wide bridge. A model is proposed to assess in various conditions the importance of the behavioural rules observed at the individual level for the regulation of traffic flow. It highlights how the interplay between the value of the flow and cooperative behaviours governs the formation and size of the clusters observed on the bridge.
蚂蚁觅食通常沿着明确的路径进行组织，这些路径支持外出和回巢个体的双向流动，并且可以推测这种流动被最大化以确保食物返回巢穴的高比率。在本文中，我们研究了瓶颈对蚂蚁流动时间组织的影响。在我们的实验中，蚂蚁必须穿过一座桥才能从巢穴到达食物源。使用了两种类型的桥：一种有瓶颈，一种没有瓶颈。交通计数表明，尽管存在瓶颈且路径宽度减小，但两座桥上的交通流量和食物返回率是相同的。这是由于流动时间组织的变化：当路径宽度减小时，观察到入巢和出巢蚂蚁交替成群地穿过桥。这种组织限制了正面相遇的数量，从而能够保持与宽桥上相同的行进持续时间。提出了一个模型，以评估在各种条件下个体层面观察到的行为规则对交通流调节的重要性。它突出了流量价值与合作行为之间的相互作用如何控制桥上观察到的集群的形成和大小。
