University of Cambridge, Department of Psychology, Cambridge, United Kingdom.
PLoS One. 2013;8(1):e52936. doi: 10.1371/journal.pone.0052936. Epub 2013 Jan 9.
Western scrub-jays (Aphelocoma californica) live double lives, storing food for the future while raiding the stores of other birds. One tactic scrub-jays employ to protect stores is "re-caching"-relocating caches out of sight of would-be thieves. Recent computational modelling work suggests that re-caching might be mediated not by complex cognition, but by a combination of memory failure and stress. The "Stress Model" asserts that re-caching is a manifestation of a general drive to cache, rather than a desire to protect existing stores. Here, we present evidence strongly contradicting the central assumption of these models: that stress drives caching, irrespective of social context. In Experiment (i), we replicate the finding that scrub-jays preferentially relocate food they were watched hiding. In Experiment (ii) we find no evidence that stress increases caching. In light of our results, we argue that the Stress Model cannot account for scrub-jay re-caching.
西部灌丛鸦（Aphelocoma californica）过着双重生活，一方面为未来储存食物，另一方面则抢夺其他鸟类的食物储存。西部灌丛鸦保护食物储存的一种策略是“重新储存”-将食物藏在潜在小偷看不到的地方。最近的计算模型研究表明，重新储存可能不是由复杂认知介导的，而是由记忆失败和压力的组合介导的。“压力模型”断言，重新储存是一种普遍储存欲望的表现，而不是保护现有储存的愿望。在这里，我们提供了与这些模型的核心假设强烈矛盾的证据：即压力驱动储存，而不考虑社会背景。在实验（i）中，我们复制了灌丛鸦优先重新储存它们被观察到隐藏的食物的发现。在实验（ii）中，我们没有发现压力增加储存的证据。鉴于我们的结果，我们认为压力模型不能解释灌丛鸦的重新储存。
