Seasonal Changes in the Thyroid Hormones of the Male Squirrel Monkey

Abstract
The serum of male squirrel monkeys was analyzed for thyroxine and triiodothyronine levels at intervals corresponding to preparation for breeding, termination of breeding well after the breeding season. Highest hormones concentrations were found prior to breeding when body weight was also highest. Significant differences in hormone levels were found across sampling period. The interaction between gonadotropins and thyroid hormones is discussed.