Sir

Payne et al. express concern at the resumption of a limited trade in elephant ivory from Namibia, Zimbabwe and Botswana to Japan, and at the system for monitoring the illegal killing of elephants (MIKE) that supports the decision by the Convention on International Trade in Endangered Species (CITES) to allow this trade (Nature 399, 297; 1999). The authors correctly identify difficulties in devising survey methods, and of relating changes in populations to underlying causes. They are also disturbed that this decision may lead to proposals for future sales. But they misrepresent or misunderstand key points.

CITES did not decide to resume a limited ivory trade. Before the 1989 ban there had been a rampant ivory trade from illegally killed elephants. CITES decided to allow a one-off limited trade this year in stockpiled ivory under tightly controlled conditions, and to monitor the impact of this trade as an ‘experiment’. Now that the sales have taken place, no further legal trade is allowed.

The 1989 ban should also have been regarded as an experiment, and monitored. When CITES meetings in 1992 and 1994 questioned whether the ivory ban was working effectively, no monitoring system was in place to provide an informed response. MIKE aims to fill a major gap by providing the best possible objective information for decision-makers.

The MIKE system was designed by IUCN, the World Conservation Union, as required by CITES. Experts were brought together from Africa and Asia, and their proposed system was passed through IUCN's elephant specialist groups for refinement, before approval by the CITES standing committee. What further peer review would Payne et al. desire?

An objective assessment of the one-off sale is not yet available. Nor has it been possible to assess the impact of the ban in any meaningful quantitative way. Yet Payne et al. assume that a total ban is the safest option for elephants, despite the numbers killed illegally since 1989. MIKE has been designed to inform debate on such issues. If there is insufficient understanding to make decisions about limited trade, the same applies to decisions about a continued ban.