Who innovates? Abundance of novel and familiar food changes which animals are most persistent.

Novel behaviours are the raw material of cultural evolution, yet we do not have a clear picture of when they are likely to arise. I use a state-dependent model to examine how individual age and energy reserves interact with the abundance of known and novel prey to promote dietary innovation (incorporating a new food item into the diet). I measure innovativeness as persistence in attempting to capture novel prey. I find a trend towards greater persistence among younger individuals. Decreased abundance of known prey and increased abundance of novel prey also favour persistence. However, many exceptions to these trends occur. These exceptions are critical because they may explain inconsistencies among studies of animal innovation. Care must be taken in experiments to control for multiple factors relevant to an animal's energy budget and foraging opportunities. We may learn more about innovation in experimental contexts by (i) manipulating the abundance of novel and familiar food resources, (ii) directly measuring animal age and condition, and-where possible-(iii) fitting nonlinear models to innovative behaviour. Results indicate that selection for persistence may also favour neophilia.