Spatiotemporal variation of behavior and repeatability in a long-lived turtle

Animal personalities represent repeatable behavioral differences exhibited by individuals in a population. Variation in personality traits across individuals is an increasingly recognized mechanism for species adaptation over time and across different contexts. In long-lived ectotherms, such as turtles, variation in personality is expected to be a major component of how they persist in habitats over their long lifespans, yet little information exists on the sources and magnitude of this variation. Here, we estimated short- and long-term variation in behavior type and repeatability of three personality traits (boldness, activity, and exploration) in wild, free-ranging ornate box turtles (Terrapene ornata). In addition, we contrasted the short-term variation in behavior types across four distinct populations. From 628 trials involving 174 individual turtles, we found consistently high repeatability in behavior types within and across years. Likewise, individual behavior types were highly repeatable within all four populations, even across several years. Despite such repeatability, we detected both geographic and temporal variation in mean differences for these otherwise stable behaviors. To our knowledge, this is the first study to document behavioral types in ornate box turtles specifically and the first to characterize the behavioral axes of activity and exploration in box turtles generally.Significance statementChelonians, which are a globally imperiled taxonomic group, have had relatively little personality research relative to other groups, yet they display the hallmarks of animal personality traits such as consistency in behavior types and evidence of among-individual variation, particularly in terms of ranging and movement. We characterized three axes of personality in four populations of ornate box turtles over multiple years. We found that individual turtles exhibited repeatable behaviors both across populations and through time, yet populations differed consistently in mean values for these traits. Geographical differences among populations were more important in shaping behavioral variation than body mass, body length, or sex. Our findings indicate that turtles have distinct personalities with short- and long-term repeatability for each behavior examined and at least multi-year repeatability for boldness and exploratory behaviors.

Automated summary

Animal personalities are repeatable behavioral differences exhibited by individuals in a population. This study focuses on the short- and long-term variation in behavior types and repeatability of personality traits in wild ornate box turtles. The results show high repeatability in behavior types within and across years, indicating distinct personalities in box turtles.