Personality is correlated with natal dispersal in North American red squirrels ( Tamiasciurus hudsonicus )

Individual natal dispersal behaviour is often difficult to predict as it can be influenced by multiple extrinsic and intrinsic factors. Individual differences in personality have been shown to be an important correlate of dispersal behaviour. However, the relationships between personality traits and dispersal are often inconsistent within and across studies and the causes of these discrepancies are often unknown. Here we sought to determine how individual differences in activity and aggression, as measured in an open-field trial, were related to natal dispersal distance in a wild population of North American red squirrels ( Tamiasciurus hudsonicus ). For 14 cohorts, while individual aggression consistently had no association with dispersal distance, the association between activity and dispersal fluctuated through time, mediated by population density. The environmental-dependence of the relationship between personality and dispersal in this population is indicative of the importance of considering external conditions when predicting dispersal behaviour.