Managing African Elephants for Ivory Production Through Ivory Trade Regulations

Abstract

(1) Most of the African elephant populations currently supplying the international ivory trade are seriously overhunted for their tusks. One way to control elephant hunting is to impose comprehensive restrictions on trade in ivory. (2) Simulation modelling was used to explore the consequences of three strategies for regulating the ivory trade: limiting the total weight of ivory harvested, limiting the number of tusks taken, and setting a minimum acceptable tusk size. (3) Limits on the weight of ivory harvested encourage overhunting and extermination of elephants. Tusk quotas which allow small increases in elephant deaths can be offset by increased fertility, but ivory production will decline with time. Setting minimum tusk weights can provide secure protection for elephant populations, but will result in low ivory offtake per elephant. (4) Natural mortality alone produces the most ivory, due to the exponential pattern of male tusk growth. The loss of highly productive years cannot be offset by increased turnover. (5) Current African ivory harvest patterns are destructive and inefficient, and could be improved by adopting trade regulations which encourage better management.