Service d'Ecologie Sociale CP. 231, Université Libre de Bruxelles, Campus Plaine, Boulevard du Triomphe 1050, Brussels, Belgium.
Proc Biol Sci. 2010 Apr 22;277(1685):1267-73. doi: 10.1098/rspb.2009.1976. Epub 2009 Dec 23.
In the ant species Tetramorium caespitum, communication and foraging patterns rely on group-mass recruitment. Scouts having discovered food recruit nestmates and behave as leaders by guiding groups of recruits to the food location. After a while, a mass recruitment takes place in which foragers follow a chemical trail. Since group recruitment is crucial to the whole foraging process, we investigated whether food characteristics induce a tuning of recruiting stimuli by leaders that act upon the dynamics and size of recruited groups. High sucrose concentration triggers the exit of a higher number of groups that contain twice as many ants and reach the food source twice as fast than towards a weakly concentrated one. Similar trends were found depending on food accessibility: for a cut mealworm, accessibility to haemolymph results in a faster formation of larger groups than for an entire mealworm. These data provide the background for developing a stochastic model accounting for exploitation patterns by group-mass recruiting species. This model demonstrates how the modulations performed by leaders drive the colony to select the most profitable food source among several ones. Our results highlight how a minority of individuals can influence collective decisions in societies based on a distributed leadership.
在 Tetramorium caespitum 蚁种中，通讯和觅食模式依赖于群体聚集招募。侦察蚁发现食物后会招募巢内同伴，并通过引导一群群的新兵到食物地点来充当领导者。过了一段时间，就会发生大规模的招募，觅食者会沿着化学痕迹前进。由于群体招募对整个觅食过程至关重要，我们研究了食物特征是否会通过领导者诱导招募刺激的调整，从而影响招募群体的动态和规模。高浓度蔗糖会触发更多群体的离开，这些群体包含的蚂蚁数量是低浓度蔗糖的两倍，到达食物源的速度也快两倍。根据食物的可及性，也会出现类似的趋势：对于一块切断的黄粉虫，血液的可及性会导致更大的群体更快地形成，而不是整个黄粉虫。这些数据为开发一个随机模型提供了背景，该模型可以解释通过群体聚集招募的物种的开发模式。该模型表明，领导者的调节如何驱使蚁群在多个食物源中选择最有利可图的食物源。我们的研究结果强调了少数个体如何能够影响基于分布式领导的社会中的集体决策。
