The top shell of a tortoise is called the carapace; the shell that covers a tortoise's belly is called the plastron. The populations of Galápagos tortoises that live on the hotter and drier islands of the Galápagos have developed shells that are saddle-shaped with a high notch above the neck. This allows them to stretch their necks higher to reach vegetation that grows above the ground.
The Charles Darwin Research Station in the Galápagos raises captive Galápagos tortoises. This conservation organization reintroduces many tortoises back into the wild once they've grown big enough that predators don't pose a danger. The only native natural predator of the Galápagos tortoise is the Galápagos hawk. The hawk preys on eggs and newly hatched tortoises. The main threats to adult tortoises are habitat destruction and illegal hunting. The Galápagos Islands, discovered by Spanish sailors in 1535, were named after the giant tortoises discovered there. Galápago means tortoise in Spanish.
Tortoises lay eggs. Females lay their eggs in nest holes, which they cover and leave. Babies hatch in four to eight months. They are on their own from the beginning.