Although giraffes have been seen occasionally south of the Niger river, there is no evidence that permanent populations occur in this area) and presumably the giraffes either die or return to the northern side. The southern habitats may be unsuitable for two reasons. First, human harassment and habitat modification may prevent the establishment of viable "southern herds". Secondly, there may be an absence or inadequacy of particular food plants or some other environmental requirement. These speculations emphasize the necessity of a thorough ecological study if, at some time in the future, conservation authorities wish to translocate giraffes into the savannas south of the Niger-Benue river system.