The blades swoop over the parched land in search of a grey haze of locusts on the horizon.
“If you don’t know what the locust swarms look like, you’re never going see them in the distance. They blend into the land,” says Max Taylour, the helicopter’s young sharp-eyed logistician.
“Look for a grey wisp in the distance. It could be a cloud behind one of the mountains.”
Then a crackle comes over the radio from headquarters – coordinates for a swarm which has been called in by one of the ground teams.
Kieran Allen, the pilot, makes an about-turn and soon the chopper is skimming over a forested mountainside in the vast Samburu National Reserve in Central Kenya.
It does not take long till the pilot spots them. “Shit, lads, it’s a big one,” Kieran shouts.
From the air, the mountain valleys are awash with millions of flitting white dots. A swarm about twice the size of the City of London ready to devour every bit of vegetation in its wake.
The winged invasion
Last year, East Africa was hit by a once-in-a-lifetime invasion of voracious desert locusts. Billions of insects poured across the border into Kenya from the Arabian Peninsula, Somalia and Ethiopia.
Commentators compared it to something from the Old Testament – a biblical plague of Abraham, driven on by climate change, wreaking havoc on the food supply of a region which regularly faces acute bouts of hunger.
There had been nothing like it in Kenya since the 1950s and officials were caught flatfooted, trying to battle swarms roughly the size of Luxembourg with a handful of planes and almost no proper equipment.
Pilots tasked with spotting the swarms sent their locations back to base on WhatsApp on shoddy rural internet connections.
A single locust swarm can contain up to 80 million locusts and fly 30 to 80 miles in one day depending on the wind. By the time, spraying planes arrived at the WhatsApp coordinates the next day, it was often too late.
The locusts had warmed up in the morning sun and moved off into the wilderness, laying millions of eggs. Every day, each locust can eat its weight in vegetation daily and multiplies twenty-fold every three months. A swarm can easily eat as much food as 35,000 people in a single day and multiple two dozen times in three months.
“It was hopeless. No one had seen it before. It was like trying to put out a forest fire with a mug of water,” says Kieran, recounting how last year he saw swarms going on for as far as the eye could see.
Kieran used to fly celebrities like Madonna and Lady Gaga around Kenya’s most luxurious resorts, but the experienced pilot was quickly drafted in to fight the invasion last year.
It took most of the year to get the invasion under control, by which time the swarms had devastated the lives of tens of thousands of subsistence farmers.
“No one had seen anything like it for 70 years,” says Keith Cressman, a top Locust guru at the United Nation’s Food and Agricultural Organisation’s (FAO).
“Kenya had no talent. No experience. No equipment. No aircraft. No network in place. They didn’t have the right pesticide sprays or know how to spray swarms. They had no systematic way of sharing information.”
“It’s a completely different ball game now,” Mr Cressman, adds.
Breaking the wave
This year the locusts are back in force, sweeping across northern Kenya. But something has changed.
A complex defence system of ground teams, helicopters and fixed-wing pesticide spraying planes worth tens of millions of pounds has been put in place.
And for now, at least, Kenya seems to be beating the winged invaders back in record time.
Hovering above the forest canopy, Max clicks the handheld tracker on. The helicopter begins to circle the area, expertly lassoing the teaming mass in an invisible GPS trail to send back to locust high command.
The swarm is about to settle down for the evening and scores of trees have already turned a purplish-green from layer upon layer of two-inch-long insects.
Roosting in the treetops, the swarm covers almost 300 hectares, but when they fly off the next morning, they will spread out across an area roughly five times that size.
Max’s coordinates are immediately fed back to one of the locust control rooms in Lewa Conservancy Trust. There, analysts working from the wildlife consultancy group 51 Degrees pour over the data, mapping the real-time movements of dozens of swarms on giant screens.
In the Lewa, data analyst Boniface Haule points to a phone in the corner. “That’s the hotline. Anyone can call in at any time to tell us if they’ve seen a swarm.”
“The pilots are always on standby ready to move immediately,” he says, clicking his fingers.
The strategy is to kill the insects en mass while they are sleeping. The pesticide they use is approved by the UN as safe but they still have to strafe the locusts when they’re miles away from a water source or human settlement.
The coordinates Max has just sent in pinpoints exactly where the swarm are settled, bunched close together in the trees below for the cold night. In the early morning, the pilots will come back for the kill.
Several lines of defence have been set up to break the waves of insects in a methodical, almost military fashion as they fly further inland.
Kenya’s first line of defence is at Garissa about 100km west of the Somali border.
When the huge swarms of locusts come over the border, helicopter pilots like Kieran fly out to identify the exact coordinates in the late evening when the locusts are starting to settle down for the night.
Pilots then wake up at the crack of dawn and fly tiny fixed-wing planes, specially fitted with pesticides sprayers, out to dive-bomb the waking swarms before they warm and fly off.
“Everything we do gives us a two hour `window in the early morning,” says Max, in a clipped British-Kenyan accent. “If you miss that, you have to start all over again.”
The giant swarms coming in from Somalia and Ethiopia are broken up into more manageable bite-size chunks. When the insects fly further inland a second division of helicopters and planes is waiting at the Lewa Conservancy to break them up into small clumps.
When the locusts begin to approach the breadbasket regions in the south of the country, they’re just about small enough that ground teams can mop up the stragglers.
Similar operations are in place across Somalia and Ethiopia, but experts say these operations are nowhere near as successful as Kenya’s.
In early February, the FAO, who are one of the driving forces behind the response, said that the swarm invasion in Kenya was already beginning to decline just over one month after the locusts crossed the border.
The FAO estimates that operations across Kenya, Somalia and Ethiopia have saved more than 3.1m metric tonnes of crop production, almost enough to feed all of Portugal for two years.
Now with a year of experience under their belts, Mr Cressman says Kenya is one of the world-beating locust hunting nations, with experts ready to train other countries.
Max and Keiran are up before the sun rises, speeding off towards the mountainside swarm in Samburu. A spraying plane is circling high above the valley, ready to be guided in.
A series of quick messages ensue between the two pilots. They need to set up the lines perfectly or risk crashing into one another.
“Eyes on him,” Kieran says in a tense voice. “Tell me if you lose visual.”
The plane needs to pass within a few feet of the dense hilltop forest to make sure he hits the swarm with all of his payload, and avoid going anywhere near the spinning blades.
Finally, they’re ready – the small white plane dives into the valley in a nail-biting arch a few feet above the teaming canopy, spewing out white vapour behind it.
“That was bloody beautiful,” Max says, as the helicopter spins around to continue on its hunt.