of different form groups often mate, producing offspring with widely differing shapes and color. Perhaps the best means of identification for the future is simply the place of origin. The smallest, and perhaps the prettiest, of the subspecies, is the Tunisian tortoise. It has a particularly bright and striking coloration. However, these are also the most sensitive tortoises of the species, so they cannot be kept outdoors in temperate climates, as cold and rainy summers quickly cause the animals to become ill. They are also incapable of long hibernation. At the other extreme, animals from northeastern Turkey are very robust, such as Hermann's tortoise. The largest specimens come from Bulgaria. Specimens of have been reported. In comparison, the Tunisian tortoise has a maximum weight of 0.7 kg (1.5 lb). T. graeca is also closely related to the marginated tortoise (T. marginata). The two species can interbreed, producing offspring capable of reproduction. Sexing Males of T. graeca differ from females in six main points. Firstly, they are generally smaller. Their tails are longer than females and taper to a point evenly, and the cloacal opening is farther from the base of the tail. The underside is somewhat curved, while females have a flat shell on the underside. The rear portion of a male's carapace is wider than it is long. Finally, the posterior plates of the carapace often flange outward. Mating and reproduction In T. graeca, immediately after waking from hibernation, the mating instinct starts up. The males follow the females with great interest, encircling them, biting them in the limbs, ramming them, and trying to mount them. During copulation, the male opens his mouth, showing his red tongue and making squeaking sounds. During mating, the female stands still, bracing herself with her front legs, moving the front part of her body to the left and right in the same rhythm as the male's cries. One successful mating will allow the female to lay eggs multiple times. When breeding in captivity, the pairs of females and males must be kept separate. If multiple males are in a pen, one takes on a dominant role and will try to mate with the other males in the pen. If more males than females are in a pen, the males might kill each other to mate with the females. One or two weeks before egg laying, the animals become notably agitated, moving around to