Development, Stability, and Consequences of Personality in the Juvenile Red Squirrel

Abstract

Animal personality – defined as consistent differences in behaviour among individuals – is a growing field in behavioural ecology due to its demonstrated effects on fitness. However, the ontogeny of personality under natural conditions remains relatively unexplored. In this thesis, I examine the development, stability, and consequences of juvenile personality in the North American red squirrel (Tamiasciurus hudsonicus). I demonstrate that 1) conditions in early life – particularly sibling relations – influence juvenile personality, 2) both aggression and activity change from juvenile to yearling stages, but activity maintains rank stability, 3) juveniles that gain territories early in the season do not experience a decrease in syndrome deviation, and 4) both dispersal activity and territory acquisition are influenced by juvenile aggression. These results suggest that environmental effects are important in shaping juvenile personality, and personality in turn influences a juvenile’s ability to meet the challenges associated with natal dispersal.