Females with young will sometimes aggregate and one to two adults may remain with all of the calves while the rest go off to feed. Calves are born after a fifteen month gestation period. The number of young is usually one, but some twins do occur. A calf is six feet tall at birth and is able to stand after about twenty minutes. Females attain full size by the age of five, and males by the age of seven.
Giraffes have horns unlike any other mammal.
They are present at birth as cartilaginous knobs which rapidly ossify. They grow slowly throughout life and are covered with skin and hair. Hair may become worn away from the apex of the horn.