The incentive value of a natural and cognitively demanding behaviour: food-caching jays as a model system

The overall objective of this research is to study how inherently rewarding it is for an animal to perform a natural and cognitively demanding behaviour. The behavior that we will study is one that jays do for a living, namely hiding food for future consumption and relying on memory to find hidden stashes at a later date ('food-caching'). From a welfare perspective, there is increasing interest in using cognitive enrichment for captive animals (i.e. providing them with tasks that are mentally challenging), but there is a lack of scientific evidence as to whether and how cognitive activities are rewarding to animals per se. The proposed studies directly address this issue by investigating what aspects of caching behaviour the jays are most motivated to perform (i.e. the jays value the most), and how these decisions are influenced by the cognitive attributes of the behaviours, such as the jays' knowledge of the likelihood of successful recovery, and the bird's current or anticipated motivational state. To address these issues, we shall develop a decision paradigm for the jays in which the choice between two perches determines access to one of two cages. The jays will be given a choice between differing numbers of cache locations in these cages to find out whether their preference for the opportunity to cache is enhanced by how hungry they are, and whether the value they place on caching also depends on whether or not they have been prevented from caching either recently, or over longer time periods. We shall also investigate whether the birds' choices are also modulated by what happens when they come to recover their caches. This is important because in order for the recovery conditions to affect the jays' caching preferences, the birds must anticipate these conditions on the basis of their past experience of recovering their caches. To test this idea, we shall determine whether or not jays assign a higher value to caching in places from which they have the opportunity to recover and whether they assign a lower value to caching a type of food that has previously been stolen or has become spoiled. We shall also ask whether the opportunity to cache is affected by their feeding motivation at the time when they cache or when they come to recover the caches, and whether they value caching in private more than when others jays are present who could witness the caching event and therefore pose a threat to their caches. Taken together these experiments will provide important information about the caching decisions that jays make and the extent to which these decisions are influenced by cognitive and motivational factors. It will thus reveal how rewarding performance of this natural behavior is under different motivational and cognitive conditions that influence the outcome of caching behavior. By providing new information about the value of performing a cognitively demanding task, the project will allow us to investigate the rationale and potential for using 'cognitive enrichment' in welfare enhancement programmes.

To assess the incentive value of caching and its modulation by motivational and cognitive processes, we shall develop a decision paradigm for jays in which the choice between two perches determines access to one of two goal cages on a concurrent variable interval schedule. Having validated this paradigm by varying the amount of food in each goal cage, jays will be given a choice between differing numbers of cache locations in these cages to investigate whether the preference for the opportunity to cache is enhanced by general and specific states of hunger and whether short- and long term deprivation of caching potentiates the incentive value of caching. Evidence for the role of cognition will come from studies on the impact of the conditions at recovery upon caching decisions. In order for the recovery conditions to affect caching, the birds must anticipate these conditions on the basis of their past experience of cache recovery. Initially, we shall determine whether or not jays assign a higher incentive value to caching in locations from which they then have an opportunity to recover and if so, whether jays devalue the opportunity to cache a specific food if it has been pilfered or degraded. Perhaps the most compelling evidence that caching involves prospective cognition comes from the discovery that it is the motivational state at recovery, rather than at caching, that is the primary determinant of caching decisions. By pre-feeding different foods at the time of caching and recovery, we shall determine whether the incentive value of the opportunity to cache is affected by the relevance of the food available for caching to the anticipated motivational state at recovery, which would provide good evidence that the rewarding properties of food-caching is modulated by cognitive processes. Finally, we shall assess the role of social cognition, namely whether the jays avoid caching in locations in which they can be observed, as opposed to cached in private.

By assessing the motivation for engaging in a natural and cognitively demanding behaviour, namely food-caching by jays, the proposed programme of research will have a direct impact upon animal welfare, a subject that is high on the public priority list. Furthermore by providing important information about the environmental needs of corvids, this research addresses critical issues in the 'Refinement' component of the 3Rs, which also has implications for legislative bodies responsible for animal welfare. Indeed it is listed under two of the BBSRC strategic policy priorities, namely (a) the 3Rs in research using animals and (b) animal welfare. Furthermore, corvids are treated as vermin or agricultural pests. Our work should affect how policy makers and the public perceive corvids, and their physical and social needs. It is therefore essential that our work receives the appropriate media attention, and the PI and co-PI will use their past experience of doing so to ensure that this will happen. Indeed our previous work has been featured on TV, radio, popular pieces in the press, and public debates. The work on corvids in general, and food caching jays in particular was also used to inspire the choreography of Rambert Dance Company's 'The Comedy Of Change', and a film 'Brainy Birds' is available at http://www.rambert.org.uk/comedy_of_change/videos. It was also chosen by Cambridge's 800th campaign as one of seven research programmes to profile: http://www.youtube.com/watch?v=y_MnwNyX0Ds. Academically, our proposed research programme should have an important impact on our understanding not only of animal welfare but also more generally on animal decision-making and preference. In the laboratory animals are typically faced with decisions between different amounts, probabilities or delay of resources. However what has not been previously studied are decisions between resources whose values are modulated by cognitive processes such as episodic-like memory and future planning. In this respect the present studies should make an important novel contribution to our understanding of the processes that determine an animal's preferences and decisions.