South Africa has sparked a big controversy with its proposal to sell a large stockpile of ivory believed to be worth $5 million. Africa’s elephant population was estimated last year at 620,000, down from 1.2 million less than 20 years ago. Although the decline seems to have been checked, in part because of a 1989 ban on international trade in ivory, many scientists are still worried about elephant populations. The South Africans argue that regulated sales of ivory acquired through natural elephant deaths and other legal means would provide badly needed funds, some of which would go toward elephant conservation programs. But wildlife officials Kenya and India warn that a resumption in ivory sales anywhere would encourage elephant poachers around the world. A showdown over the issue is expected next week when delegates to the Convention on International Trade in Endangered Species convene in Kenya.