Inferring the sex and age of African elephants from tusk measurements

Abstract The key problem in evaluating the impact of the international ivory trade on the African elephant population is the limited information available. The most reliable data come from ivory trade statistics, and much information can be gained by analysing tusks in the trade. The sex of African elephants can be inferred from tusk measurements by considering total length and circumference in combination, and their age can be estimated from tusk weight or circumference. Age estimates for females are less accurate than those for males, but when small samples are used, accuracy can be increased by using models which only consider elephants up to the age of 30 years. By combining inferences of sex and age, mortality patterns of African elephants can be inferred from tusks in the ivory trade, and these patterns can help study the impact of hunting on African elephant populations.