Worldwide Hunt Is On for Ivory Substitutes : Animals: Ban on African elephant tusks prompts search for alternative material. ‘Vegetable ivory’ from South American palm tree nuts is one novel source.

Outlawing the lucrative international trade in African elephant ivory has reverberated from South America to Siberia, touching off a global scramble for alternative sources.

Hippopotamuses are hunted for their big teeth, walruses and wart hogs for their tusks. South American palm tree nuts are harvested for their “vegetable ivory.” Except for Alaskan walrus tusks, all are legal elephant-ivory substitutes. So are the tusks of long-extinct woolly mammoths.

The first worldwide ban on trading African elephant ivory, authorized by the Convention on International Trade in Endangered Species (CITES), a conservation organization, has been in effect since January, 1990. Member nations declared the wild African elephant to be an endangered species because of fears that it was headed for extinction by 2000.

The elephants were slaughtered for their ivory in record numbers in the 1980s, their populations dwindling from an estimated 1.3 million to as few as 400,000. An average of 200 to 300 elephants were killed every day, 80% to 90% of them illegally.

International trade in elephant ivory had become a $500-million-a-year business, with Japan the biggest customer. Most U.S. ivory imports were jewelry, ornamental carvings, art objects and trinkets. The largest amount came from Hong Kong.

“The international ivory market has flattened, and poaching is way down, but it’s a tenuous balance. People are still stockpiling ivory, hoping there’ll be a change in two or three years. We’re not out of the woods yet,” said Diana McMeekin of Washington, senior vice president of the African Wildlife Foundation.

From Europe to the Far East, ivory carvers are seeking substitutes that can imitate what, in many ways, is the inimitable quality of elephant ivory.

“At the very beginning of the ban, some elephant ivory was being sneaked into the United States by people claiming it was from mammoths,” said Edgard Espinoza, chief of the crime section of the National Fish and Wildlife Forensic Laboratory in Ashland, Ore.

But an analysis of the crosshatched patterns in the ivory can detect the difference, he said. In elephant tusks, the features are rounded; in mammoths, pointed.

“It’s just as easy to switch to another animal to continue the ivory trade. The number of hippos killed in Kenya for their teeth has risen,” Espinoza said. “Ivory from African wart-hog tusks also is showing up.”

Conservationists fear that Pacific walruses, like the elephants, may be perilously poached. More than 200,000 walruses make up the herd shared by the United States and Russia in the Bering Sea region. About 10,000 are legally harvested each year.

Wanton walrus “headhunting”--shooting the animals with rifles, then sawing off their heads and hacking out their tusks--was the target of a two-year undercover operation by special agents of the U.S. Fish and Wildlife Service in Alaska.

Disclosed in mid-February, the operation snared a network involved in illegally trading walrus ivory for drugs and cash. Nearly 700 pounds of raw ivory were sold to undercover agents. A walrus head could command at least $500.

Although walruses are not endangered, they are classified as “protected” by the federal Marine Mammal Protection Act of 1972, which prohibits killing them just for their ivory. Walruses may be hunted only by American Indians for subsistence purposes in a “non-wasteful manner.” Walrus tusks may be used only in the carving of traditional native handicrafts.

The Russians are mining the millions of mammoth tusks preserved in the permafrost of northern Siberia. Ancient ancestors of the elephant, mammoths became extinct more than 11,000 years ago.

A seemingly inexhaustible supply of several hundred thousand tons of their curved ivory may be uncovered in the Siberian storehouse. The browner tusks go for about $100 a pound; the best grade can bring about $400 a pound.

Ivory-like in look, color and texture, rock-hard, golf-ball-size tagua nuts from South America are being fashioned into jewelry, buttons and figurines.

“We are encouraging the use of this ‘vegetable ivory’ because it’s a renewable resource,” says Michael Sutton, senior program officer at the World Wildlife Fund.