Belgrad Benjamin A, Griffen Blaine D
Marine Science Program, School of the Earth, Ocean, and Environment, University of South Carolina, 701 Sumter Street, EWS 617, Columbia, SC, 29208, USA.
Department of Biological Sciences, University of South Carolina, Columbia, SC, 29208, USA.
Oecologia. 2017 Jun;184(2):431-440. doi: 10.1007/s00442-017-3886-4. Epub 2017 May 20.
Assessing the stability of animal personalities has become a major goal of behavioral ecologists. Most personality studies have utilized solitary individuals, but little is known on the extent that individuals retain their personality across ecologically relevant group settings. We conducted a field survey which determined that mud crabs, Panopeus herbstii, remain scattered as isolated individuals on degraded oyster reefs while high quality reefs can sustain high crab densities (>10 m). We examined the impact of these differences in social context on personality by quantifying the boldness of the same individual crabs when in isolation and in natural cohorts. Crabs were also exposed to either a treatment of predator cues or a control of no cue throughout the experiment to assess the strength of this behavioral reaction norm. Crabs were significantly bolder when in groups than as solitary individuals with predator cue treatments exhibiting severally reduced crab activity levels in comparison to corresponding treatments with no predator cues. Behavioral plasticity depended on the individual and was strongest in the presence of predator cues. While bold crabs largely maintained their personality in isolation and group settings, shy crabs would become substantially bolder when among conspecifics. These results imply that the shifts in crab boldness were a response to changes in perceived predation risk, and provide a mechanism for explaining variation in behavioral plasticity. Such findings suggest that habitat degradation may produce subpopulations with different behavioral patterns because of differing social interactions between individual animals.
评估动物个性的稳定性已成为行为生态学家的一个主要目标。大多数个性研究都采用单独的个体，但对于个体在生态相关的群体环境中保持其个性的程度却知之甚少。我们进行了一项实地调查，结果表明，在退化的牡蛎礁上，赫氏互敬蟹（Panopeus herbstii）仍以孤立个体的形式分散存在，而高质量的礁石能够维持较高的蟹密度（>10只/平方米）。我们通过量化同一批螃蟹在单独和自然群体状态下的胆量，研究了这些社会环境差异对个性的影响。在整个实验过程中，螃蟹还分别接受了捕食者线索处理或无线索对照处理，以评估这种行为反应规范的强度。与无捕食者线索的相应处理相比，有捕食者线索处理时，螃蟹在群体中的胆量明显大于单独时，且螃蟹的活动水平显著降低。行为可塑性取决于个体，并且在有捕食者线索的情况下最为强烈。虽然大胆的螃蟹在单独和群体环境中基本保持其个性，但害羞的螃蟹在同种个体中时会变得大胆得多。这些结果表明，螃蟹胆量的变化是对感知到的捕食风险变化的一种反应，并提供了一种解释行为可塑性变化的机制。这些发现表明，由于个体动物之间不同的社会互动，栖息地退化可能会产生具有不同行为模式的亚种群。
