Extant Unless Proven Extinct: The International Legal Precedent

Jared Diamond ( 1987) correctly described the dilemma of assessing the status of taxa sought but not found during faunal surveys, and of compiling lists of extinct species based on those surveys. Is their extinction implied if they are not found, or must they be presumed still extant until proven extinct? Inherent in any such discussion is the assumption that a survey, in the correct geographic locality and habitat, has been made recently by one or more competent field biologists, or at least by experienced amateurs, who could identify the taxa in question. I agree completely with Diamond's presentation and wonder how many readers realize this is more than an academic problem. The "extant unless proven extinct" dilemma has had a formal place in international conservation law since 20 March 1979, when it was the subject of debate at the Second Meeting of the Conference of the Parties to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), convened in San Jose, Costa Rica. Because Article II of CITES requires that Appendix I contain all species threatened with extinction and affected by trade, and that Appendix II contain species that might become threatened, it is clear that CITES deals with living species and excludes extinct taxa. However, when CITES was drafted in 1973, species were listed in the appendices on the basis of diverse data, some exhaustive and some frivolous. As a consequence, some taxa were inappropriately listed. In 1976, at the First Meeting of the Conference of the Parties to CITES in Berne, Switzerland, an attempt was made to improve the listing process. Criteria were adopted that set a biological standard for adding and deleting taxa from the appendices. In addition to data on the actual or potential negative impact from trade, the criteria set forth in Resolution of the Conference 1.1 (Berne 1976) for addition of taxa to Appendix I require biological data on its status from any of a variety of sources. In descending order of preference, these are (1) hard scientific data collected over a number of years that demonstrate trends in population size and geographic range; or lacking that, (2) data from a single survey of population size and range; or if that is not available, (3) reports from reliable, nonscientific observers; or in the absence of any of the above types of data, (4) reports on habitat destruction, excessive trade, or other potential causes of extinction. The companion Resolution Conf. 1.2 for deletion of taxa from Appendix I requires more rigorous data than are used for addition of species, data that "must transcend informal or lay evidence of changing biological status and any evidence of commercial trade which may have been sufficient to require the animal or plant to be placed on an appendix initially; and should include at least a well-documented population survey, indication of the population trend sufficient to justify deletion, and an analysis of the potential for commercial trade in the species or population." After these criteria were developed in Berne, the Parties decided to go back and review the appropriateness of the taxa that had been listed in the Appendices prior to their adoption. That review was initiated at the Special Working Session of the Parties to CITES, held in Geneva, in 1977, and has continued at every subsequent meeting. The continuing review process led Australia to worry about several possibly extinct species that earlier had been placed on Appendix I at the insistence of that nation. At the Costa Rica meeting in 1979, the Australian delegation questioned how appendix species that were presumed to be extinct should be treated. They pointed out that the documented data on species believed to be