The number of years it takes for a tortoise to reach this size depends upon how well it has eaten.
Males begin to develop a concave plastron near the tail.
A female's plastron remains almost flat throughout life. Typically, the male bobs his head at the female and nips at her front legs and the front edges of her shell. He even shoves her. This differs from fighting, wherein tortoises try to flip one another over. The harassment by the male usually causes the female to stand still and pull in her head and limbs.