Date of Award

Fall 12-2015

Degree Type


Degree Name

Doctor of Philosophy (PhD)



Committee Chair

Heidi Lyn

Committee Chair Department


Committee Member 2

Stanley Kuczaj

Committee Member 2 Department


Committee Member 3

Alen Hajnal

Committee Member 3 Department


Committee Member 4

David Echevarria

Committee Member 4 Department


Committee Member 5

Susan Friedman

Committee Member 5 Department



In the wild, California sea lions (Zalophus californianus) are exposed to a wide array of sensory information at all times. However, it is impossible for captive environments to provide this level of complexity. Therefore unique procedures and practices are necessary for the maintenance of physiological and psychological health in captive animals (Wells, 2009). This project aims to explore the behavioral effect of scent added to the environment, with the goal of improving the welfare of captive sea lions by introducing two scent types: 1.) Natural scents, found in their native environment, and 2.) Non-natural scents, not found in their native environment. The use of scent to add complexity to the captive environment has been utilized with big cats (Szokalski, Litchfield & Foster, 2012; Wells, 2009), canids (Steele & Steele, 2005), and other zoo-housed species (Wells, 2009) yet this method has not been explored in marine mammals. Nor has this approach been documented in the scientific literature for use with captive sea lions, despite caretaker reports that scents may be a fruitful approach for captive sea lion enrichment. Scent enrichment was found to significantly impact sea lion behavior, as demonstrated by a reduction in pattern swimming, increased habitat utilization, and reduction in stereotypical behavior, however, there appears to be no relationship between these variables and a preference between natural and non-natural scents.