Investment decisions in grey squirrels: the role of future discounting and executive control (Ref: 4264)

投资行为必然涉及对未来的规划。它可以在不同的物种中表现出多种形式，并需要一定程度的执行控制：投资者需要抑制立即使用资产，以将其储存起来，以备将来不可避免地不确定。投资决策为动物对未来的预期提供了一个窗口，并且可以预期会随着生活史参数而变化。灰松鼠是研究投资的理想模型物种，因为它们是天生的多产投资者，在食物充足的时候储存坚果，在食物稀缺的时候提供可靠的食物来源。松鼠不仅决定是否储存或食用食物，而且储存本身涉及一系列捕食和盗窃风险的权衡，这些权衡与食物价值有关。因此，投资决策直接反映了未来的贴现，应该紧密相连的执行control.Project的目的和MethodsThis博士项目将调查未来贴现和执行控制的野生灰松鼠在投资决策中的作用，作为长期的实地研究生活在埃克塞特大学校园松鼠的一部分。有两个主要目标：开发松鼠执行控制的可靠分析方法，并记录它们的投资决策和成功回收食物的结果，作为延迟满足的成本和收益的现实衡量标准;从综合模型中生成和测试缓存行为的预测，这些模型考虑了最佳觅食和（从行为生态学传统）和贴现和执行控制的认知机制通过设计实地实验来验证执行控制的抽象实验室测试，学生将在自由生活的松鼠中产生可靠的执行控制措施，并测量其自然投资决策的结果。学生将构建基于执行控制和未来贴现的适应性投资行为的数学模型，以生成他/她将通过收集野外松鼠的实验数据进行测试的预测。

Investment behaviour necessarily entails planning for the future. It can take many forms across species, and requires some degree of executive control: investors need to inhibit immediate use of an asset to store it away for a future which is, inevitably, uncertain. Investment decisions provide a window into an animal's expectations about the future and can be expected to vary with life-history parameters. Grey squirrels are an ideal model species for studying investment because they are natural and prolific investors, storing nuts during times of plenty to provide a reliable source of food when it is scarce. Squirrels not only decide whether to cache or eat a food item, but caching itself involves a series of predation and pilferage risk trade-offs, which co-vary with food value. As such, investment decisions directly reflect future discounting and ought to be tightly linked to executive control.Project Aims and MethodsThis PhD project will investigate the role of future discounting and executive control in investment decisions made by wild grey squirrels, as part of a long-term field study of squirrels living on the University of Exeter campus. There are two key aims: develop reliable assays of executive control in squirrels and record their investment decisions and outcomes in terms of successful food recovery, as a real-life measure of the costs and benefits of delaying gratification;generate and test predictions of caching behaviour from integrative models that consider both optimal foraging (from the behavioural ecology tradition) and the cognitive mechanisms of discounting and executive control (from experimental/cognitive psychology).By devising field experiments to verify abstract laboratory tests of executive control, the student will generate reliable measures of executive control in free-living squirrels and measure the outcomes of their natural investment decisions. The student will construct mathematical models of adaptive investment behaviour based on executive control and future discounting, to generate predictions that he/she will test by collecting experimental data on wild squirrels in the field.