Seasonal Reproductive Cycle of Wild Alligator Snapping Turtles (Macrochelys temminckii) in Southwest Georgia

Abstract

We studied the reproductive cycle of wild Macrochelys temminckii (Alligator Snapping Turtle) in southwest Georgia from March 2008 to September 2010. We measured plasma testosterone (T), estradiol (E2), and corticosterone (C). Seasonal changes in T were observed in males, with maximum concentrations occurring in October. Evidence of mating and male combat were seen in April. Females displayed seasonal changes in T and E2 concentrations, with peaks occurring in March and April, respectively, (in association with mating and ovulation) and again in September and October, respectively, (in association with follicular development and vitellogenesis). We observed oviductal eggs (mean clutch size = 28.5) in April. Concentrations of C were not significantly different between months. Reproductive patterns coincided with seasonal variation in temperature and water level.