Who are the innovators? Understanding individual differences in problem-solving behaviour in wild house mice

Abstract

Animals often face challenges that require them to come up with solutions to novel problems or to find new solutions to existing ones; i.e., they need to innovate. However, not all individuals in a population are equally likely to solve novel problems, and it is unclear which individual characteristics make a successful innovator. Theoretical frameworks suggest the importance of intrinsic (e.g., individual characteristics) and extrinsic (e.g., environmental conditions) factors on innovation. Understanding the mechanisms behind these differences is essential for advancing our knowledge of animal cognition. As innovation is shaped by multiple factors, it is paramount to understand its ontogeny, the barriers individuals face when encountering novel opportunities, and the evolutionary mechanisms that maintain individual differences in innovative behaviour. Innovation happens in multiple steps, as individuals must first discover new opportunities, assess their safety and value, and then attempt to exploit them. These steps present distinct barriers, influenced by each individual’s space use, personality, motivation and persistence, leading to trade-offs with other life-history traits. Individuals vary in their innovation propensity depending on their ecological and social contexts, which highlights the importance of both intrinsic and extrinsic factors that shape innovation. This thesis contributes to the study of animal innovation by providing novel experimental evidence on the fundamental causes of individual variation in innovative behaviour. It examines proximate factors of innovation, such as the effects of personality, ontogeny, and reproductive decisions, as well as ultimate factors, by exploring the evolutionary forces that maintain variation in innovation. Individual differences in innovation propensity emerge early in life and solidify during adolescence. Behavioural traits and reproductive strategies influence how individuals allocate their time, with more active individuals exploring their environment more extensively and engaging more frequently with novel problems. On a broader evolutionary scale, sexual selection can maintain this variation in innovative performance through mate choice. While innovation can offer advantages, such as increased resource acquisition and reproductive success, it also involves trade-offs, including greater exposure to risk and time investment. In a world where environmental change accelerates due to human activity, understanding the role of innovation in species adaptation is increasingly critical. Investigating how motivation, persistence, and ecological pressures interact to shape innovation will be key to predicting species’ responses to rapid environmental changes