Wilson Conor D, Arnott Gareth, Elwood Robert W
Quercus, School of Biological Sciences, Queen's University Belfast, UK.
Behav Processes. 2012 Mar;89(3):299-303. doi: 10.1016/j.beproc.2011.12.006. Epub 2011 Dec 27.
Animals often show behavioural plasticity with respect to predation risk but also show behavioural syndromes in terms of consistency of responses to different stimuli. We examine these features in the freshwater pearl mussel. These bivalves often aggregate presumably to reduce predation risk to each individual. Predation risk, however, will be higher in the presence of predator cues. Here we use dimming light, vibration and touch as novel stimuli to examine the trade-off between motivation to feed and motivation to avoid predation. We present two experiments that each use three sequential novel stimuli to cause the mussels to close their valves and hence cease feeding. We find that mussels within a group showed shorter closure times than solitary mussels, consistent with decreased vulnerability to predation in group-living individuals. Mussels exposed to the odour of a predatory crayfish showed longer closures than control mussels, highlighting the predator assessment abilities of this species. However, individuals showed significant consistency in their closure responses across the trial series, in line with behavioural syndrome theory. Our results show that bivalves trade-off feeding and predator avoidance according to predation risk but the degree to which this is achieved is constrained by behavioural consistency.
动物在捕食风险方面常常表现出行为可塑性，但在对不同刺激的反应一致性方面也表现出行为综合征。我们在淡水珍珠贻贝中研究这些特征。这些双壳类动物常常聚集在一起，大概是为了降低每个个体的捕食风险。然而，在有捕食者线索的情况下，捕食风险会更高。在这里，我们使用光线变暗、振动和触摸作为新的刺激来研究进食动机和避免被捕食动机之间的权衡。我们展示了两个实验，每个实验都使用三种连续的新刺激来使贻贝关闭它们的瓣膜，从而停止进食。我们发现，群体中的贻贝比单独的贻贝关闭时间更短，这与群居个体被捕食的脆弱性降低相一致。暴露于捕食性小龙虾气味中的贻贝比对照贻贝关闭时间更长，突出了该物种的捕食者评估能力。然而，个体在整个试验系列中的关闭反应表现出显著的一致性，这与行为综合征理论相符。我们的结果表明，双壳类动物根据捕食风险权衡进食和避免被捕食，但实现这一点的程度受到行为一致性的限制。
