Does personality affect the exploration stage of juvenile dispersal in a fossorial rodent (Tamias dorsalis)?

Background/Question/Methods:   The movement of organisms away from their birthplace, termed natal dispersal, reduces local density of conspecifics, increases gene flow, and affects individual fitness. Understanding the proximate and ultimate consequences of natal dispersal on individual fitness and population persistence can have important consequences for conservation given that climate and anthropogenic forest change creates numerous conservation challenges. Personality, also called behavioral phenotype, is a set of observable behaviors in an individual that are the result of its genotype interacting with the environment and may influence a juvenile’s exploration method as it disperses. We asked the following questions about personality and dispersal of a fossorial rodent population (cliff chipmunk; Tamias dorsalis) on Mt. Graham in the Pinaleño Mountains, AZ: 1) Do different personalities exist in the juveniles of this population? And 2) Does personality affect the exploration of habitat by dispersing juveniles? To answer these questions, we captured juveniles after emergence from their natal nest, performed two behavioral tests in a closed arena to measure activity/exploration (the Open Field test) and sociality/aggression (the Mirror Image Stimulation test), and radio-collared individuals to track exploratory movements as individuals dispersed from the natal area.

Results/Conclusions: In our initial year, we found that 1) personalities do exist in juvenile cliff chipmunks. Juvenile males are more likely to avoid an image of a conspecific than juvenile females that showed no clear preference for their attraction or avoidance of their image. We also found that 2) personalities affected the path distance individuals moved during exploration.  Highly active individuals explored longer path distances than less active individuals; however, no difference existed between males and females for the distance explored during dispersal.  Our results demonstrate that personalities exist and that these behavioral differences could affect juvenile dispersal.  This work will be continued in 2014 to further elucidate the effect of personalities on natal exploration.