Specialization and plasticity are important for many forms of collective behavior, but the interplay between these factors is little understood. In insect societies, workers are often predisposed to specialize in different tasks, sometimes with morphological or physiological adaptations, facilitating a division of labor. Workers may also plastically switch between tasks or vary their effort. The degree to which predisposed specialization limits plasticity is not clear and has not been systematically tested in ecologically relevant contexts. We addressed this question in 20 freely-foraging bumble bee (Bombus terrestris) colonies by continually manipulating colonies to contain either a typically diverse or reduced (“homogeneous”) worker body size distribution, over two trials. Pooling both trials, diverse colonies did better in several indices of colony performance. The importance of body size was further demonstrated by the finding that foragers were larger than nurses even in homogeneous colonies with a very narrow body size range. However, the overall effect of size diversity stemmed mostly from one trial. In the other trial, homogeneous and diverse colonies showed comparable performance. By comparing behavioral profiles based on several thousand observations, we found evidence that workers in homogeneous colonies in this trial rescued colony performance by plastically increasing behavioral specialization and/or individual effort, compared to same-sized individuals in diverse colonies. Our results are consistent with a benefit to colonies of predisposed (size-diverse) specialists under certain conditions, but also suggest that plasticity or effort, can compensate for reduced (size-related) specialization. Thus, we suggest that an intricate interplay between specialization and plasticity is functionally adaptive in bumble bee colonies.

中文翻译：

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工人体型的多样性对大黄蜂群体的表现重要吗？

专业化和可塑性对于许多形式的集体行为很重要，但是这些因素之间的相互作用却鲜为人知。在昆虫社会中，工人往往倾向于专门从事不同的工作，有时需要进行形态或生理上的适应，以利于分工。工人还可以在任务之间灵活切换或改变他们的工作量。倾向的专业化限制可塑性的程度尚不清楚，并且尚未在生态相关的环境中进行系统的测试。我们在20只自由觅食的大黄蜂（Bombus terrestris）中解决了这个问题），通过在两个试验中不断操纵菌落，使其包含典型的多样化或减少的（“均质”）工人体型分布。综合两个试验，不同菌落在菌落性能的几个指标上表现更好。研究发现，即使在体型范围非常狭窄的同质菌落中，觅食者也比护士大，这进一步证明了体型的重要性。但是，大小多样性的总体影响主要源于一项试验。在另一项试验中，同质和多样的菌落表现出可比的性能。通过根据几千个观察结果比较行为概况，我们发现证据表明，该试验中同质殖民地的工人通过塑性地增加行为专业化和/或个人努力来挽救殖民地的表现，与不同殖民地的同等规模的人相比。我们的结果与在一定条件下有利于（多样化）专家群体的利益相一致，但也表明可塑性或努力可以弥补（规模相关）专业化程度的下降。因此，我们建议在大黄蜂群体中，专业化和可塑性之间的复杂相互作用是功能性的。