Abstract: Little information is available regarding the adrenal activity of Steller sea lions (Eumetopias jubatus) in relation to season and behavior. The objective of this study was to test for seasonal changes in fecal corticosterone concentrations and potential relationships to behavioral scoring in captive Steller sea lions. For this study, fecal samples were obtained opportunistically over a 3-y period (September 2001 to September 2004) from three adult (1 male, 2 female), reproductively intact, long-term captive Steller sea lions housed at the Alaska SeaLife Center in Seward, Alaska. Daily behavior scores based on a scale of 1 (poor) to 5 (excellent) of appetite, energy, attention, sociability, and enrichment were also recorded. The male (SSL-01) had a significantly higher fecal corticosterone concentration in the breeding season, while one of the females (SSL-03) had a significantly higher fecal corticosterone concentration in between the molting and breeding seasons. Fecal corticosterone concentration was significantly higher for one of the females (SSL-03) in comparison to the other female (SSL-02; p 0.001). There was a significant negative relationship between behavior score and fecal corticosterone concentrations for the male and one female (SSL-03). The results of this study do indicate that Steller sea lions have a highly seasonal physiology that can be reflected in the fecal corticosterone concentrations of both sexes.
Key Words: Steller sea lion, Eumetopias jubatus, corticosterone, stress, season, behavior
Document Type: Research article
Page Numbers: 168-174