Department of Psychology, University of Cambridge, Cambridge, UK.
Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy.
Sci Rep. 2021 Jan 12;11(1):835. doi: 10.1038/s41598-020-80515-7.
Previous research reported that corvids preferentially cache food in a location where no food will be available or cache more of a specific food in a location where this food will not be available. Here, we consider possible explanations for these prospective caching behaviours and directly compare two competing hypotheses. The Compensatory Caching Hypothesis suggests that birds learn to cache more of a particular food in places where that food was less frequently available in the past. In contrast, the Future Planning Hypothesis suggests that birds recall the 'what-when-where' features of specific past events to predict the future availability of food. We designed a protocol in which the two hypotheses predict different caching patterns across different caching locations such that the two explanations can be disambiguated. We formalised the hypotheses in a Bayesian model comparison and tested this protocol in two experiments with one of the previously tested species, namely Eurasian jays. Consistently across the two experiments, the observed caching pattern did not support either hypothesis; rather it was best explained by a uniform distribution of caches over the different caching locations. Future research is needed to gain more insight into the cognitive mechanism underpinning corvids' caching for the future.
先前的研究报告指出，鸦科动物更喜欢在没有食物的地方储存食物，或者在没有食物的地方储存更多特定的食物。在这里，我们考虑了这些预期的缓存行为的可能解释，并直接比较了两个相互竞争的假设。补偿式缓存假说表明，鸟类学会在过去食物供应较少的地方储存更多特定的食物。相比之下，未来规划假说表明，鸟类回忆特定过去事件的“何时何地”特征，以预测食物的未来供应情况。我们设计了一个方案，其中两个假设预测了不同的缓存位置的不同缓存模式，以便可以区分两种解释。我们在一个贝叶斯模型比较中形式化了这些假设，并在两个实验中对一个之前测试过的物种，即欧亚松鸦进行了测试。在两个实验中，观察到的缓存模式都不支持任何一个假设；相反，它最好用不同缓存位置上的缓存的均匀分布来解释。未来的研究需要深入了解鸦科动物未来储存食物的认知机制。
