Males fight for females during mating season by butting heads. The gestation period for giraffes is about 15 months. A single calf is born, rarely twins. Calves are usually 6 ft. tall and can stand up 20 mins. after birth. Behavior Females stay in their mothers' territories, males leave in all-male groups to search for females in heat.
Males are distinguishable at a distance from females because of their different grazing habits.
Males tend to stretch their necks to reach the tops of taller trees, while females tend to bend over smaller trees. Giraffes can usually be found together in groups of 12-15. There are no permanent members of the group. Females are usually the most alert to danger. When startled, a giraffe can gallop at speeds up to 30 mph.