Investment decisions in grey squirrels: the role of future discounting and executive control. PhD in Psychology (NERC GW4+ DTP)

Lead Supervisor
Dr. Lisa Leaver, Department of Psychology, College of Life and Environmental Sciences, University of Exeter

Additional Supervisors
Dr. Tim Fawcett, Department of Psychology, College of Life and Environmental Sciences, University of Exeter
Dr. Sean Rands, School of Biological Sciences, University of Bristol

Location: University of Exeter, Streatham Campus, Exeter, EX4 4QJ

This project is one of a number that are in competition for funding from the NERC GW4+ Doctoral Training Partnership (GW4+ DTP). The GW4+ DTP consists of the GW4 Alliance of research-intensive universities: the University of Bath, University of Bristol, Cardiff University and the University of Exeter plus five unique and prestigious Research Organisation partners: British Antarctic Survey, British Geological Survey, Centre for Ecology & Hydrology, the Natural History Museum and Plymouth Marine Laboratory. The partnership aims to provide a broad training in the Earth, Environmental and Life sciences, designed to train tomorrow’s leaders in scientific research, business, technology and policy-making. For further details about the programme please see http://nercgw4plus.ac.uk/

For eligible successful applicants, the studentships comprises:

- A stipend for 3.5 years (currently £15,009 p.a. for 2019/20) in line with UK Research and Innovation rates
- Payment of university tuition fees;
- A research budget of £11,000 for an international conference, lab, field and research expenses;
- A training budget of £3,250 for specialist training courses and expenses.
- Travel and accommodation is covered for all compulsory DTP cohort events
- No course fees for courses run by the DTP

We are currently advertising projects for a total of 10 studentships at the University of Exeter

Project Background

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 a food item, eat it, or reject it, 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 Methods

This 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:

1) generate testable 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);

2) 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.

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. By devising field experiments to verify abstract laboratory tests of executive control, he/she will generate reliable measures of executive control in free-living squirrels and measure the outcomes of their natural investment decisions. There are multiple directions the work could take and we are particularly interested to hear from students who want to play an active role in designing the project.