The international ivory trade was banned in 1989 - so why has poaching again reached crisis levels in recent years? European sales of elephant tusks could be putting this iconic species in danger.
Loopholes in the ban are part of the problem, say conservationists. Since 1989, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) has outlawed the international trade in ivory - but it still allows sales on domestic markets.
And there are other exceptions. Ivory can be moved between countries as "personal effects" for non-commercial purposes, including tusks brought home from trophy hunting expeditions.
Sales in antique and "pre-convention ivory" - dating from before African elephants were listed by #link:https://cites.org/common/resources/pub/Elephants_in_the_dust.pdf:CITES# as endangered in 1976 - are also legal, as is the trade in mammoth ivory.
Elena Tennigkeit, owner of German company Ox-Gallstone GmbH, which trades in ivory and other raw materials, told DW she buys elephant tusks from private homes and auctions - for example hunting trophies inherited by a generation who wouldn't dream of hanging them on the wall. "Nobody in Europe wants ivory any more," she said. "People don't like it."
In much of Asia, on the other hand, it is prized as "white gold" - a desirable luxury commodity. Tennigkeit says Europe's old ivory supplies a limited, elite demand in Asia that would otherwise be met with poached ivory.
"If Europe destroys the ivory it has, that won't help the elephants," she said.
Sending a signal
Some conservationists disagree. They say destroying ivory stockpiles - as countries such as Kenya, the United States and China have done since 1989 - sends a graphic signal that buying ivory is unacceptable.
And signals are important. Travers said recent experience shows that rather than eliminating the demand for poaching, the legal trade sends a message that ivory is still very much a viable market.
When Botswana, Namibia, Zimbabwe and South Africa successfully lobbied for the endangered status of their elephant populations to be downgraded, opening the way for "one-off" sales of ivory stockpiles in 1999 and 2008, poaching increased.
Between 30,000 and 50,000 elephants were killed annually in the years following the 2008 sale of African ivory to China. Tanzania alone lost an average of more than 1,000 elephants a month between 2009 and the end of 2014.
"As we predicted, this actually stimulated demand - sending a signal that the ivory trade was still alive and still desirable," said Travers. "I think one can only draw the conclusion that (these sales) were the trigger for this massive escalation in poaching - which had up until that point been pretty well suppressed."
Ivory burn in Brazzaville, Republic of Congo, where President Nguesso set fire to their entire stockpile of nearly five tonnes of illegal ivory
Furthermore, campaigners like Daniela Freyer of the Munich-based conservation group Pro Wildlife are concerned about the "laundering" of illegally poached ivory. "No one can really tell how old the ivory is," Freyer told DW.
Pre-convention ivory can only be exported with certification of age - and ivory dealer Tennigkeit insists obtaining this is a complex and expensive process that leaves little room for doubt over the ivory's provenance.
But Freyer argues certificates can be faked. There are also concerns that once the ivory reaches the Asian market, even genuine certificates can be doctored and reused to import illegal ivory.
Conservationists like Travers and Freyer say that lessons have been learned from the experiment in "one-off sales," and that there is renewed momentum to crack down on the ivory trade.
In January, Hong Kong - a major hub for the international ivory trade - announced that it would ban ivory imports and exports, and take steps to phase out its domestic market. This came on the heels of similar commitments made by the US and China in a joint agreement last year. China is the biggest end-market for ivory, with some estimations making the US come in second.
But the world's biggest exporter of pre-convention ivory, the European Union, is lagging behind.
"The EU needs to send out a political signal," said Freyer. "With more and more countries destroying ivory stockpiles and banning domestic markets, you really miss the EU's voice in these international declarations. The EU is simply continuing with its ivory trade."
France, Germany, the United Kingdom, Austria, Sweden, and the Netherlands have already banned exports of pre-convention elephant tusks, and called on other EU member states to do the same.
But because it is still possible to move ivory within the EU, ivory from countries with an export ban still finds its way onto the international market. That's why many argue that restrictions are needed on an EU-level.
The European Commission says it has no evidence that legal trade in old ivory items in the EU is used to launder illegal ivory. But spokesperson Enrico Brivio told DW that a new EU action plan against wildlife trafficking to be presented in March would "contemplate" the large volumes of pre-convention ivory being exported from Europe.
"We want to make sure that this does not fuel the demand for ivory in Asia, which has been increasing considerably in the last decade," Brivio said.
It remains to be seen whether the plan will lay the groundwork for a ban on Europe's remaining ivory trade. But Travers, who delivered a carload of hand-signed petitions to the 1989 meeting that ushered in the ban, says concerned elephant lovers have more power than ever to push for action.
"With the development of social media, today we can all engage and be aware, petition our [parliamentarians], we can support field initiatives at the press of a button - that's a major game-changer in the whole democratization of this process."