Data from: Collective response of leaf-cutting ants to the effects of wind on foraging activity

One advantage of sociality is to mitigate environmental restrictions through collective behavior. Here we document a colony-level response of leaf-cutting ants to wind, an environmental factor that impedes foraging. Given that larger ants adhere more strongly to the substrate, increasing forager size in windy conditions should reduce the negative effect of wind. We tested this idea for Acromyrmex lobicornis in windy regions of Patagonia. We examined (1) whether the fraction of larger ants versus smaller ants increased in windy conditions and (2) whether the effect of wind on the ants’ movement was lower for larger ants. The size-frequency distribution of foragers was skewed more toward larger ants in nature under more windy conditions. Under windy conditions in the field, the mobility of smaller ants was more reduced than that of larger ants. The change toward larger foragers in windy conditions reduced the negative effect of wind by 32%, illustrating how a social organism can collectively mitigate the adverse effects of the environment.社会性的优势之一，是通过集体行为缓解环境限制带来的影响。本文记录了切叶蚁（leaf-cutting ants）对阻碍觅食活动的环境因子——风的蚁群级响应。针对巴塔哥尼亚多风区域的洛氏阿克罗切叶蚁（Acromyrmex lobicornis），我们验证了如下假说：体型更大的蚂蚁对基底的附着强度更高，因此在多风环境中提升觅食蚁的体型占比，应当能够削弱风所带来的负面影响。我们开展了两项检验：其一，多风环境下大型觅食蚁的种群占比是否显著提升；其二，风对蚂蚁移动能力的抑制作用是否在体型更大的个体中更弱。野外观测结果显示，在风力更强的自然生境中，觅食蚁的体型频率分布更偏向大型个体。野外多风条件下，小型觅食蚁的移动能力受抑制程度显著高于大型个体。多风环境下觅食蚁体型向大型个体的转变，使风的负面影响降低了32%，这一结果直观展现了社会性生物如何通过集体行为缓解环境的不利影响。