Twenty-Third Annual Meeting and Symposium of the
Desert Tortoise Council, April 3-5, 1998
Abstracts

An analysis of courtship behavior of the desert tortoise, Gopherus agassizii, was conducted at the Desert Tortoise Conservation Center near Las Vegas, Nevada. From Fall 1996 to Fall 1997, 18 male and 18 female desert tortoises were housed in outdoor semi-natural enclosures. Fifty randomly selected pairings were chosen from this group and their interactions were recorded on video camera. To determine the effects of body size on courtship behavior, I recorded duration of Phases I (trailing), II (subduing), and III (mounting), total duration of courtship, number of times the male bites the female, number of times the male rams the female, and number of times the mounted male fell off the female. Preliminary results suggest that with an increasing ratio of male to female mass, number of bites increases (p<0.05). Additionally, number of rams is positively correlated with number of bites (p<0.05). Results from this study will add to current knowledge of tortoise reproductive behavior. If differences in behavior between smaller (younger) and larger (older) males are observed, translocation practices may begin to take into account the size of the released tortoises. For example, if only young males are released, they might not mate successfully until they are older, resulting in a decline in birth rate. In order for translocated populations to endure, older individuals might need to be released in addition to younger ones.