Sexual maturity of the female is at 48-60 months, the male is at 42 months. The giraffe mate at any time of the year with the gestation period being between 453 - 464 days. There is usually only one calf, very rarely twins.
A giraffe cow in season attracts males from all around, but is soon won by a dominant bull. He drives off the subordinate bulls by threatening them; fighting is rarely necessary at this stage. A giraffe's pregnancy lasts fifteen months, after which the cow will go to a traditional calving ground used by females time and time again to have her single calf. Giraffe calves are born with horns, which is unusual. The horns lie flat against the baby's skull when it is born, but pop up during the first week of life.
The calving ground ensures that the young calf is always left in a group of young giraffes of about the same age when its mother goes off to feed in the middle of the day. Even so the calves are heavily predated by hyenas, leopards, and wild dogs, and only about half of them will survive their first six months.
As the calf grows older it joins its mother. Lions become its main enemy, but a female giraffe can kill a lion with a well-aimed kick of its front feet. After the calves are a year old, less than one in ten will die in each year.
Weaning takes fifteen months, although a calf's mother will mate again five months after her calf is born. A young female stays in her mother's home range but young males form all-male 'clubs', and wander away when they are about three years old.Read More: Food and Feeding