Proper timing of the reproductive cycle to assure mate access is critical to optimizing success. We tested the importance of male presence on the progression of the female reproductive cycle in the blood python, Python curtus. Upon reaching sexual maturity, captive-born, individually raised virgin female snakes were housed with either a conspecific male or female. At the onset of the reproductive season (late autumn), all females initiated early follicular growth; however, only females housed with males initiated vitellogenesis, and these females ovulated and oviposited viable eggs. Females not housed with males showed arrested follicular development in that they maintained hydrated, nonvitellogenic follicles that underwent follicular regression after three months. The requirement for male presence prior to vitellogenesis is premature for fertilization but assures the female of a mate prior to mobilizing substantial energy stores into reproduction. Once an energy investment is made, females commit to completing the cycle.

Section editor: R. E. Gatten Jr