A giraffe is pregnant for about 15 months. During this gestation period, a mother giraffe often returns to the grounds where she was born to birth her own calf.
Giraffes do not have specific mating seasons, so calves can be born at any point throughout the year. Mother giraffes remain standing during birth, which causes the calf, or rarely twin calves, to fall almost 6 feet to the ground. The calves are able to stand and run within an hour of being born. This is vital because there are many predators in their habitat, including lions, hyenas and leopards. Calves stand nearly 6 feet tall at birth and within the first year can grow another 6 feet. They rely on their mother's milk for up to a year. After that, males are big enough to join new herds, but females typically spend their entire lives with their mother's herd.