Personality and metamorphosis: is behavioral variation consistent across ontogenetic niche shifts?

Understanding the manner by which individual differences in personality arise and are maintained in animal populations is currently a topic of considerable research interest. This is particularly the case when it comes to developmental processes and understanding how behaviors change over ontogeny. Such developmental perspectives are essential given that the vast majority of animal species possess complex life cycles or undergo some form of metamorphosis. Yet, in spite of the broad taxonomic relevance and the obvious potential importance of metamorphosis for understanding the basis of consistency in personality over ontogeny, almost no research has been done on this topic. Using the lake frog (Rana ridibunda) as a study organism, we tested whether individual-level differences in personality (activity, exploration and boldness) were consistent within both larval and juvenile frog life-history stages and across metamorphosis. We found that most behaviors of interest were highly consistent within a given life-history stage and at least some traits were consistent across metamorphosis (e.g., activity and exploration). Generally, more active, exploratory individuals in novel experimental arenas were also bolder and more likely to spend time in more risky open areas of a familiar environment. To our knowledge, our study is the first to both characterize personality traits across anuran development and provide evidence of consistency in behavior across metamorphosis in a vertebrate species.