Circling 600 feet above the ground, its thermal camera trained on the scrubland below, the drone keeps silent watch for its target.
When a telltale white blur appears on screen, the aircraft will drop closer to earth to confirm the identity of its quarry before summoning armed backup.
This is not the militant strongholds of Afghanistan or Pakistan but the African bush. The target is the critically-endangered black rhino and those illegally hunting it.
As the demand for rhino horn soars, driven by buyers in Asia for its reputed medicinal properties, so too does the sophistication of the poachers.
Faced with hunting gangs using helicopters, night-vision goggles and high-powered rifles, those protecting the rhinos are also being forced to up their game.
This weekend, The Daily Telegraph witnessed the first flight of an Unmanned Aerial Vehicle, or drone, in pursuit of suspected poachers in South Africa.
The small, lightweight, battery-powered Falcon drones can be launched by hand in minutes and fly over a range of five miles for up to 90 minutes. Fitted with high-resolution infrared cameras, they can pick out elephants, rhinos and lions as well as anyone that might be tracking them.
Their operators use statistical analysis of when and where previous rhino killings took place to direct the UAVs and position the rangers close to poaching “hot spots”.
When suspected hunters are identified, those tracking them can be prepared with the knowledge of how many they are facing and if they are armed. Once arrests are made, they will have video footage to put before the courts.
Those behind the project, which is co-ordinated by the Endangered Wildlife Trust, hope that by using the controversial technology, they can help turn the tide in the battle against poachers and a £6.6 billion wildlife trafficking industry which, it is now claimed, could be fuelling terrorism. In December, the US upgraded wildlife trafficking to a national security threat amid reports poaching helps fund, among others, al-Shabaab militants in Somalia.
In South Africa, home to most of the continent’s rhinos, the war against poachers is being lost. Since 2007, with a growing middle class in China, Vietnam and Thailand buying ground rhino horn to treat ailments including “devil possession” and cancer, rhino deaths have rocketed by 3,000 per cent.
In 2011, 448 South African rhinos were killed. So far this year, 350 have died and it is projected the toll will reach 750 by December.
The country’s flagship national park, the Kruger, has lost more than 50 per cent of its rhinos since 2010. The national army has been sent to help rangers take the poachers on and there are almost daily reports of violent gun battles and mounting human casualties along with the rhinos.
There are now fears that with the army making poaching more difficult in the state-owned section of Kruger, they will step up their activities in the privately-owned conservancies to the west, home to some of the country’s last black rhinos.
When the Falcon drone’s creator Chris Miser arrived at Olifants West conservancy at the foot of the Klein Drakensberg mountains of Limpopo last weekend, he planned to run some simple test flights to get used to the bushy terrain.
These were abandoned when a call came through on Saturday afternoon from a neighbouring reserve that two of their rangers had been shot at by suspected poachers – one taking a bullet in his hand-held radio.
Twenty minutes later, Mr Miser’s drone soared into the air with the aid of a bungee cord attached to a thorn tree.
As it climbed upwards, its wings turned orange by the setting sun, Mr Miser and the rangers gathered around his laptop balanced on the back of a pickup truck.
“That’s us there, there’s a giraffe and I think that’s a herd of impala,” Miser, a former US Air Force engineer who maintained drones during the Iraq war, pointed out to his audience on a small screen displaying the drone’s infrared view.
The aircraft can scan the ground to a resolution of 3cm – “we could do a count of your guinea fowl population while we’re up here,” he added.
But of the poachers, there was no sign. “They took their shoes off so we couldn’t track which way they went, and they’re probably over the fence by now,” said Craig Spencer, Oliphants West’s chief warden.
A veteran of the South African bush wars, Mr Spencer said his military training was fast becoming more important than his anthropological education.
“Many of these guys are former Mozambican rebel fighters who come over the 250-mile border to the east,” he said. “They’re carrying R5 assault rifles that you can only get from the South African military. They booby-trap rhino carcasses. Some suspects stopped recently were carrying AK47s but also had bodyguards with them.
“Every time this war rears its ugly head, we take our old rusty tool box out of the shed. We polish our tools, give them bigger badges and pay them bigger salaries but we need to keep ahead of the game. We need to use technology. I have nine people to defend 10,000 hectares. If we try to fight it using the same rusty old toolbox, we are going to lose. This drone has the potential to become the most valuable tool we have.”
The idea to use drones in anti-poaching is not unique – several have been tested in other parts of South Africa and Kenya.
But military technology comes with a price tag, and some governments are nervous about allowing its unrestricted use within their airspace.
Mr Miser has sought to solve this by using civilian materials for the Falcon and making the aircraft short-range. Critically for such remote areas, it can been operated by the average ranger and is easily repairable.
The drone itself costs $15,000 (£10,000) and $23,000 with the cost of the camera, ground control equipment and training factored in – roughly equal to one ranger’s annual salary.
“This will do the job of at least 10 rangers on the ground and make the ones you do have more effective,” he said. “The drone can also work for its money by helping with animal counts and mapping.”
In the vast landscapes of the Greater Kruger National Park, even aerial searches can be like looking for a needle in a haystack.
Enter Dr Tom Snitch, a former arms adviser to US President Ronald Reagan and University of Maryland mathematical modeller who also works for the UN’s Wildlife Enforcement Monitoring System.
Just as advertisers target consumers online with products they will like most based on Google searches and their Facebook status updates, Dr Snitch will look at where rhinos like to graze, where they were killed before, the phases of the moon, the weather, the time of day and day of week to determine where and when poachers will strike next.
“We can put all these variables into the computer and come out with algorithms,” he said. “You can’t fly over the whole park but by creating this mathematical model, you can fly over the hot spots and when you see people coming two and a half kilometres out, you have time to get your rangers in position.”
Dr Snitch’s models have previously been used to catch those laying roadside bombs in Afghanistan and Iraq, as well as arsonists in US cities. He believes that coupling them with a drone offers a unique solution.
The use of such enterprise in the war against poaching can count on some powerful friends, he adds.
In December, Hillary Clinton, the then US Secretary of State, upgraded wildlife trafficking from a conservation issue to a national security threat. There have been reports that in Africa, poaching helps to fund al Shabaab militants in Somalia, Renamo rebels in Mozambique and Uganda’s Lords Resistance Army.
“Over the past few years wildlife trafficking has become more organised, more lucrative, more widespread, and more dangerous than ever before,” Mrs Clinton said. “We are increasingly seeing wildlife trafficking has serious implications for the security and prosperity of people around the world.”
Last week during a conference at St James’ Palace in London, the Prince of Wales spoke of the parallel tragedy of the loss of the world’s wildlife.
Watched by his son the Duke of Cambridge, whose wife Catherine is expecting a baby in July, he told his audience: “As a father and a soon-to-be grandfather, I find it inconceivable that our children and grandchildren could live in a world bereft of these animals.
“Humanity is less than humanity without the rest of creation. Their destruction will diminish us all.”