On a recent Sunday a team of rangers slung backpacks and assault rifles into a helicopter for the flight to a remote part of Garamba, a vast national park in Democratic Republic of Congo.

Pilot Frank Molteno ferried the rangers in two groups of five to a clearing next to a papyrus bog where their nine-day patrol would begin: watching for elephants, listening for gunshots and hunting for poachers.

Garamba National Park's elephants were decimated last year, with 114 killed, still less than the 132 killed in 2014.

Across Africa more than 30,000 elephants are poached every year to feed demand in Asia where a kilogramme (2.2 pounds) of raw ivory fetches around $1,100 (990 euros). Some of the tusks stored in a metal trunk inside a triple-padlocked strong room in Garamba weigh more than 30 kilogrammes each.

"In 2015 the situation was really bad," said Alhadji Somba Ghislain, Garamba's 46-year old assistant park manager, who works for the Congolese Institute for the Conservation of Nature (known by its French acronym, ICCN).

"We are fighting groups which are real threats, they are militaries. It is a real war," he said.

The elephant poachers of Garamba, as elsewhere in Africa, share a willingness to kill and die for their quarry, but little else. Rebel groups, renegade soldiers, regional militaries, armed cattle herders, gunmen on horseback and villagers with muskets are all held responsible.

- South Sudan, LRA, Janjaweed fighters -

South Sudan is the source of the greatest threat. "I see the whole of South Sudan as an armed group," said Erik Mararv, the 30-year old park manager who runs Garamba for conservation non-profit organisation African Parks.

That chaotic war-torn nation spews its disorder across the shared border into the north of the park. Rangers have arrested South Sudanese poachers, had numerous firefights and seized weapons and uniforms of the South Sudan army, the SPLA, said Ghislain.

Mararv reckons armed groups from South Sudan are responsible for "80 percent" of elephant killings.

The Lord's Resistance Army (LRA), a Ugandan-led rebel group whose 150 remaining members maraud mercilessly around Central Africa also poach ivory, trading tusks for weapons.

The group's extravagant brutality over three decades -- including massacres, mutilation and mass abductions -- means its role in the illegal ivory trade attracts disproportionate attention, even though it is now responsible for just a small fraction of the poaching in Garamba.

"The LRA is an organisation on its way down," said Mararv. "We still have poaching by LRA but if you compare it to the larger scheme, especially poaching from South Sudan, it's not a big deal."

It was not always this way. On the afternoon of January 2, 2009, the LRA attacked Nagero, the park headquarters on the southern bank of the Dungu River killing 10 people.

Among the dead was Silu Masika, an 18-year old girl with a one-week old baby. Her father Alexis Tamwasi, a 60-year old ranger, has raised the orphaned child as his own and still seeks revenge.

"If I find any LRA, I shoot him," he said.

- Helicopter gunmen kill from above -

Local Congolese villagers also poach inside the park, but while they may take a shot at an elephant if the opportunity arises, they are more focused on killing antelopes, buffaloes and hippos for meat.

The most enduring raiders are armed Janjaweed horsemen from Sudan, who conduct long-range poaching missions across Central Africa. They killed around 300 elephants in Cameroon's Bouba N'Djida park in early 2012, ambushed and killed rangers in Chad's Zakouma park later that year and are blamed for wiping out Garamba's northern white rhinos in 2006.

They travel for months at a time in militarised caravans, cutting a swathe through wildlife across thousands of kilometres.

Armed nomadic cattle-herders also launch regular incursions, bringing their cows to graze in the park's north and carrying out poaching raids from their cattle camp bases. It was at one such camp that three rangers and a Congolese soldier working with them were killed in a firefight in October.

After that deadly incident, Mararv said, the park authorities have let it be known that anyone found with a gun will be arrested and the camps have dispersed, for now.

- Conservation as conflict -

One further group of killers is the most mysterious, flying over the park in unknown helicopters.

The first recorded incident was in March 2012 when 22 elephants were killed over two days, all shot in the top of the head. A dozen were killed in the same way a month later. Eight were killed the following year, and the same number died in the most recent attack last August.

The only groups with helicopters in the area are the armies of Uganda, South Sudan and DR Congo, the United Nations peacekeeping mission and a US operation to hunt down LRA leader Joseph Kony.

The Ugandan army denied Congolese accusations that it was responsible for the first killing.

"Until now, we don't know where these helicopters are coming from, but we are investigating," said Ghislain.

The variety, range and determination of the armed groups arrayed against Garamba's elephants mean this is more like conflict than conservation, but the park managers and rangers understand the threat and embrace the challenge.

"I don't want my children to ask, 'Where is the elephant?' like they ask, now, 'Where is the white rhino?'" said Tamwasi, the ranger whose daughter died at the hands of the LRA.