Department of Mathematics, London School of Economics, London, UK.
J R Soc Interface. 2012 May 7;9(70):869-79. doi: 10.1098/rsif.2011.0581. Epub 2011 Oct 19.
Scatter hoarders are animals (e.g. squirrels) who cache food (nuts) over a number of sites for later collection. A certain minimum amount of food must be recovered, possibly after pilfering by another animal, in order to survive the winter. An optimal caching strategy is one that maximizes the survival probability, given worst case behaviour of the pilferer. We modify certain 'accumulation games' studied by Kikuta & Ruckle (2000 J. Optim. Theory Appl.) and Kikuta & Ruckle (2001 Naval Res. Logist.), which modelled the problem of optimal diversification of resources against catastrophic loss, to include the depth at which the food is hidden at each caching site. Optimal caching strategies can then be determined as equilibria in a new 'caching game'. We show how the distribution of food over sites and the site-depths of the optimal caching varies with the animal's survival requirements and the amount of pilfering. We show that in some cases, 'decoy nuts' are required to be placed above other nuts that are buried further down at the same site. Methods from the field of search games are used. Some empirically observed behaviour can be shown to be optimal in our model.
分散囤积者是指将食物（如坚果）储存在多个地点以备后用的动物（如松鼠）。为了在冬季生存，动物必须回收一定数量的食物，即使这些食物可能已经被其他动物偷走。最佳的囤积策略是一种在最坏的偷食者行为下最大化生存概率的策略。我们修改了 Kikuta 和 Ruckle（2000 年《J. 优化理论与应用》）和 Kikuta 和 Ruckle（2001 年《海军研究后勤学》）研究的某些“积累博弈”，这些博弈模型化了资源最优多样化以应对灾难性损失的问题，并包括在每个囤积点隐藏食物的深度。最优的囤积策略可以作为新的“囤积博弈”中的平衡点来确定。我们展示了食物在地点之间的分布和最优囤积的地点深度如何随动物的生存需求和偷食量而变化。我们表明，在某些情况下，需要在其他埋藏在同一地点的坚果上方放置“诱饵坚果”。我们使用了搜索博弈领域的方法。我们的模型可以解释一些观察到的最佳行为。
