There are few more dangerous places on earth for elephant than Ruaha in central Tanzania.
Over the past year, poachers have had a devastating impact.
They’ve killed thousands of elephants. It is slaughter at an unprecedented rate.
Our guide, Zacharia, has lived here all his life. He’s seen odd and depressing changes to the elephant population.
There are no longer any animals with really big tusks. They’ve been taken by poachers.
You might call it unnatural selection.
"We’re also seeing more elephants with one tusk," he says.
"I believe it’s a genetic problem, but because the poachers leave them alone, they’re becoming more common."
It’s just over a year since more than 40 nations gathered in London to promise action to end the trade in ivory and other illegal animal products; a trade reckoned to be worth some £12billion - on a par with drug smuggling, arms dealing and people trafficking.
This week, they’re meeting again in Botswana to assess progress.
At best, it is patchy.
"It’s no use having laws against ivory smuggling if the legislation is not enforced properly," says Mary Rice of the Environmental Investigations Agency.
In Tanzania, a special task force including the military, is being deployed in what many are calling Africa’s new war.
On their biggest raid, our cameras followed them to the remote west of the country; to Katumba.
In the dead of night they surround and surprise a sleeping gang of poachers.
There are ninety arrests and weapons seized. But whatever ivory they had is long gone.
The gang are blamed for killing hundreds of elephants in the Katavi National Park and using the proceeds to arm rebel groups in the neighbouring Democratic Republic of Congo.
It’s just one example of poaching’s malign links to wider African problems.
The ivory trade is big business, the gangs highly organised, fuelling corruption that leads to the top.
"They arrest the small time players who might make a few hundred pounds from each elephant," says Mary Rice.
"But the people making millions seem to act with impunity." Video.