Date of Award

Spring 5-2018

Degree Type


Degree Name

Doctor of Philosophy (PhD)



Committee Chair

Lucas Keefer

Committee Chair Department


Committee Member 2

Lauren Highfill

Committee Member 3

Donald Sacco

Committee Member 3 Department


Committee Member 4

Richard Mohn

Committee Member 4 Department

Educational Research and Administration


Despite the wide acceptance of animal personality as a valid area of study, research on marine mammal personality remains remarkably scarce. What literature does exist predominantly focuses on bottlenose dolphins (Frick, 2016; Highfill & Kuczaj, 2007; Kuczaj, Highfill & Byerly, 2012; Lilley, de Vere, Yeatre & Kuczaj, 2018; Moreno, Highfill & Kuczaj, 2017). There is also strong evidence for individual differences in grey seals (Robinson et al., 2015; Twiss & Franklin, 2010; Twiss, Culloch & Pomeroy, 2011; Twiss, Cairns, Culloch, Richards & Pomeroy, 2012), and preliminary research has provided evidence of broad personality factors in pinniped species using behavioral coding (de Vere, Lilley & Highfill, 2017) and trait rating methods (Ciardelli, Weiss, Powell & Reiss, 2017). Several aspects of personality are not well documented across many taxa, including age-related patterns, the species-relevance of emotional trait words, potential issues associated with the non-human Dominance factor, and the convergent validity of multiple methods. The current study therefore aimed to address these issues in two pinniped species, California sea lions and harbor seals, and provides the first cross-method validation of personality dimensions in these taxa. There was some evidence that pinniped trainers could reliably rate the emotional states experienced by these species. Trait rating assessments produced three personality factors for each species; these exhibited good cross-method convergence in California sea lions, but not harbor seals. Dominance rankings were correlated with one behavioral and one rating factor in each species, although this was somewhat confounded by the extremely close correspondence of dominance and age.