The booming illegal trade of wildlife has put huge pressure on a treaty signed by more than 180 countries.
The booming illegal trade of wildlife has put huge pressure on a treaty signed by more than 180 countries -- the Convention on International Trade in Endangered Species (CITES),
The plight of Africa's rhino and elephants, targeted for their horns and tusks, is expected to dominate much of the 12-day meeting.
"(We) will consider changes to the trade controls of close to 500 species of wild animals and plants, including elephant, lion, pangolin, rhino and rosewood," CITES secretary general John Scanlon said.
"While all 183 CITES parties are deeply committed to the survival of wild animals and plants, they sometimes have differing views on the best way to achieve this."
A coalition of 29 African countries is pressing for a total halt to the ivory trade to curb poaching of elephants, but other delegates believe it would only fuel illegal trading.
A recent census revealed that the savannah elephant population has declined by 30 percent over seven years.
Britain's Prince William said in a pre-CITES speech this week that the census confirmed that "one of our planet's most treasured species is on course for extinction at the hands of poachers and traffickers".
He added that when he was born there were one million elephants roaming Africa, but they could be extinct in the wild when his one-year-old daughter Charlotte turns 25.
CITES forbids trade in elephant ivory, but Namibia and Zimbabwe have made a proposal asking for permission to sell off stockpiles to raise funds for local communities that co-exist with the animals.
On rhino horn trafficking, CITES banned that trade 40 years ago, but prohibition has not reduced illicit hunting, which has recently boomed in South Africa.
Around 5,000 white rhino -- a quarter of the population -- have been slaughtered over the past eight years, with the majority killed in South Africa, home to 80 percent of the world's rhino.
Rhino poaching is driven by insatiable demand in Vietnam and China for the horn, which is mistakenly believed to have medicinal powers curing everything from hangovers to cancer.
Other species high on the CITES radar are pangolins, rock geckos, tomato frogs and the African grey parrot.
Scanlon warned that illegal wildlife trafficking was "occurring on an industrial scale, driven by transnational organised criminal groups".
Besides animals, timber will be in focus.
When it first came into force in 1975, CITES only regulated a handful of timber species, but three years ago there were 600 types of timber listed under its appendices.
This year there are 250 species proposed for listing, especially of sought-after rosewood.
The meeting, described by organisers as the largest and most important CITES event since its founding, will be attended by around 3,500 delegates and opened by South African President Jacob Zuma.
Illegal wildlife trade is valued at around $20 billion a year, according to CITES, and is ranked among the world's largest illicit businesses of arms, counterfeit goods, drugs and human trafficking.