The sex of the tortoise juveniles is determined by external characteristics such as the shape of the tail, carapace, plastron or anal scutes. In most cases this determination can take place at a carapace length of circa 100 mm at an age of 3-4 years for Testudo hermanni boettgeri and of circa 130 mm at an age of 6-7 years for Testudo marginata. Juveniles are defined as male or female not before at least two different sex characteristics, in general the shape of the tail and anal scutes, are deciding.
The photo shows a male Testudo hermanni boettgeri, characterized by a long thick tail.
Temperature dependent sex determination is a well known phenomena for many species. We have studied in detail the influence of constant and variable incubation temperatures on sex ratio for Testudo hermanni boettgeri and Testudo marginata. Below, some results for Testudo hermanni are shown.