African elephant tusks grow throughout their whole lives and can increase up to 18 cm per year. Theoretically, therefore, the older the elephant, the longer its tusks, but not in every region the old elephants have them equally long. The length of the tusks depends on such factors as diet - if it is rich in micronutrients necessary for their growth and on the region in which they live. The elephants from the Hwange National Park, unfortunately, cannot boast of such long tusks as their relatives, e.g. from Kenya.