Murakami Hisashi, Tomaru Takenori, Nishiyama Yuta, Moriyama Toru, Niizato Takayuki, Gunji Yukio-Pegio
Department of Earth & Planetary Sciences, Kobe University, Kobe, Hyogo, Japan.
Science & Technology Entrepreneurship Laboratory (e-square), Osaka University, Osaka, Japan.
PLoS One. 2014 May 19;9(5):e97870. doi: 10.1371/journal.pone.0097870. eCollection 2014.
Emergent behavior that arises from a mass effect is one of the most striking aspects of collective animal groups. Investigating such behavior would be important in order to understand how individuals interact with their neighbors. Although there are many experiments that have used collective animals to investigate social learning or conflict between individuals and society such as that between a fish and a school, reports on mass effects are rare. In this study, we show that a swarm of soldier crabs could spontaneously enter a water pool, which are usually avoided, by forming densely populated part of a swarm at the edge of the water pool. Moreover, we show that the observed behavior can be explained by the model of collective behavior based on inherent noise that is individuals' different velocities in a directed group. Our results suggest that inherent noise, which is widely seen in collective animals, can contribute to formation and/or maintenance of a swarm and that the dense swarm can enter the pool by means of enhanced inherent noise.
由群体效应产生的涌现行为是集体动物群体最显著的特征之一。为了理解个体如何与邻居互动，研究这种行为很重要。尽管有许多实验利用集体动物来研究社会学习或个体与社会之间的冲突，比如鱼和鱼群之间的冲突，但关于群体效应的报道却很少。在这项研究中，我们表明，一群招潮蟹可以通过在水池边缘形成密集的群体部分，自发地进入通常会避开的水池。此外，我们表明，观察到的行为可以用基于固有噪声的集体行为模型来解释，固有噪声是指在有向群体中个体的不同速度。我们的结果表明，在集体动物中广泛存在的固有噪声有助于群体的形成和/或维持，并且密集的群体可以通过增强的固有噪声进入水池。
