Species may be split-listed meaning that some populations of a species are on one Appendix, while some are on another. Some people argue that this is risky as specimens from a more protected population could be 'laundered' through the borders of a Party whose population is not as strictly protected. The African bush elephant ("Loxodonta africana") is currently split-listed, with all populations except those of Botswana, Namibia, South Africa and Zimbabwe listed in Appendix I. Those of Botswana, Namibia, South Africa and Zimbabwe are listed in Appendix II. Listing the species over the whole of its range would prevent such 'laundering' but also restricts trade in wildlife products by range states with good management practices. There are also species that have only some populations listed in an Appendix. One example is the pronghorn ("Antilocapra americana"), a ruminant native to North America. Its Mexican population is listed in Appendix I, but its U.S. and Canadian populations are not listed (though certain U.S. populations in Arizona are nonetheless protected under the Endangered Species Act).