TitleRelationships between annual cycles of testosterone, corticosterone, and body condition in male red-spotted garter snakes, Thamnophis sirtalis concinnus
Publication TypeJournal Article
Year of Publication2000
AuthorsMoore, IT, Lerner, JP, Lerner, DT, Mason, RT
JournalPhysiological and Biochemical Zoology
Volume73
Pagination307-312
Type of ArticleJournal Article
ISSN1522-2152
Abstract

Over a 2-yr period, we investigated the annual cycles of plasma testosterone and corticosterone and the relationships between these hormones and body condition in a wild population of male red-spotted garter snakes, Thamnophis sirtalis concinnus. In the 10 mo that were sampled, a peak in testosterone was observed in late summer during gametogenesis and declining through the spring breeding period. Corticosterone and testosterone cycles were positively correlated, in contrast to many vertebrates, suggesting the lack of a direct negative interaction between the two hormones. Body condition, defined as the residual of the regression of mass on snout-vent length, also cycled annually, with individuals being more robust during the summer than during the spring or fall. Individuals with a positive body condition had significantly lower plasma levels of corticosterone than did individuals with a negative body condition, supporting the energetic role of glucocorticoids. There was no relationship between body condition and testosterone. This study suggests that annual cycles of testosterone, corticosterone, and body condition can be associated with one another, and considering all three simultaneously is necessary to understand their control and function.

URL<Go to ISI>://WOS:000088611300007
DOI10.1086/316748