They say Lake Natron is the most toxic lake on Earth.
The alkalinity in the water is not far off from household bleach. The wind barely ruffles the lake’s salt-saturated water, making it act as a mirage that can deceive migrant birds, thousands of which lie mummified on the shores. When the water dries, razor-sharp plates of soda are uncovered, making it impossible for most animals — let alone humans — to cross.
But, just over two years ago, a handful of filmmakers decided they needed to go there.
Behind most of the wildlife documentaries that have made your jaw drop and eyes pop in recent years is a team in Bristol, England, called Silverback Films. Working extensively on Sir David Attenborough-narrated projects for Netflix and the BBC — Our Planet, A Perfect Planet, things that tend to have “planet” in the title — Silverback specializes in scouring the globe to find glimpses of nature that few people, if any, have ever seen.
The company, which wildlife filmmakers Alastair Fothergill and Keith Scholey founded in 2012, comprises a rag-tag team of photographers, producers, and editors who come together like Avengers when they are commissioned for a project. They work on each series for years, researching, planning, and liaising with scientists in order to film in some of the most inhospitable places on the planet.
When they decided to tackle northern Tanzania’s Lake Natron in 2019, they knew it would be a challenge. It ended up being even more frightening than they had anticipated.
“You and I wouldn't even be having this conversation were it not for volcanoes,” Huw Cordey tells Inverse. “They have provided the air we breathe and the land we sit on.”
Cordey is the series producer of A Perfect Planet, which aired on BBC One in January 2021. He was also the producer-director of its first episode, “Volcano.” Attenborough explains in his introduction that without the powerful underground forces volcanoes trigger, there would be no breathable atmosphere on our planet.
Cordey was looking for sequences that would demonstrate both the hostility of volcanoes and the animals who use them to their advantage. One of the sequences sees a female iguana using the warm ash in a volcanic crater as the perfect incubator for her eggs. In another, river otters hunt for fish in water kept warm by boiling-hot underground magma.
But it was Lake Natron that would provide the episode's most spectacular footage.
“You have to have a producer who's willing to take risks.”
Lake Natron sits on the northern flank of the volcano Ol Doinyo Lengai. Every few years it is paid a visit by as many as a million visitors of one particular kind: flamingos. In order to breed, the birds fly thousands of miles to the middle of the 1,040km² lake, which is fed by underground springs from Ol Doinyo Lengai. Before making their journey, they wait for conditions to be perfect: The lake needs to be drying out but still contain enough water that it leaves a substrate of soda and salt, out of which the flamingos can build individual mounds. On the mounds, above the danger of the water level, sit their eggs.
The lake is hostile. Its water is so still that pilots lose their reference to the ground. In 2007, a helicopter crashed into the lake. “Everything is working against you,” says camera operator Matt Aeberhard.
But the footage the team wanted to capture would mean traveling to the lake and getting to grips with it in all its gruesome glory. They wanted to film the flamingo chicks being born but, crucially, they also wanted to capture the three-mile journey the young birds take as they travel on foot in a huge crèche towards springs on the lake's edge. The footage they got was even more dramatic than they had imagined.
Cordey was at the same company as Aeberhard in the 1990s and knew that he would be a major asset. Aeberhard, who lives in Vermont and owns a turkey that appears onscreen during our Zoom call, has filmed Lake Natron before. Cordey speaks highly of him (Aeberhard, not the turkey), and the admiration is reciprocal.
“No matter how good your team is, you have to have a producer who's willing to take risks,” says Aeberhard. “Without Huw's bravery there, we wouldn't have got this particular one off the ground.”
Two crucial members of the team remained. One was assistant producer Darren Williams. With Cordey tied up in editing the rest of that episode, Williams would be the man at the coalface, charged with tackling the everyday hurdles in East Africa — a job that required a huge amount of perseverance and ingenuity.
Once the footage had been captured, they needed a world-class editor to wade through it all. Sam Rogers is used to distilling as much as 90 hours of film into a sequence that will end up lasting for several minutes on screen. His job was to find order amidst the chaos.
Planning the sequence was a challenge. The flamingos don't travel to Lake Natron every year, and they don't even stick to the same month when they do.
“It's not seasonal,” says Cordey, “which is even more difficult for us to predict and plan shoots.”
Teamwork would be their savior. Because of Aeberhard's connections, they knew that a doctor, Pat Pattern, regularly flies over the lake and could report back on its condition and whether the flamingos had arrived. For months on end, Williams feverishly checked satellites over the water. “You have to monitor the lake constantly to find your window of opportunity,” says Aeberhard.
Around Christmas 2018, a flame of hope was extinguished when the flamingos did land in the lake, but their eggs were washed away. Shortly after that, the dry weather held. “We knew that we had a chance,” says Williams.
“You do absolutely have to trust the capabilities of the person you're with.”
He, Cordey, and production coordinator Tash Dummelow sat around a coffee table at the Silverback office. The conditions looked perfect. They needed to decide whether to go for it. Cordey looked at them and said he trusted them. “Nothing had happened at this point,” says Williams, “but it was like buying a ticket to the lottery.”
The team had already spent around $35,000 on a hovercraft — the only vehicle that could traverse the lake. It had taken three months to get it to Tanzania, where a local fixer held onto it. When they arrived, Williams and Aeberhard went out onto the water with Moses, a local with mechanical expertise. There, they saw “a blanket of pink shimmer,” in Williams' words. He put a drone up into the air and it showed them an enormous nesting site. They had found their flamingos.
Using the hovercraft was not the wacky adventure it might seem like. The mud and soda plates under the water tore apart the vehicle's rubber bottom. “The novelty wore off very, very, very fast,” says Williams. At one point, Aeberhard and Moses had to work together when the hovercraft broke down in Williams' absence.
“That was an incredibly worrisome time,” says Aeberhard. “No one's necessarily coming to get you.” Moses had to clean engines and get soda off the vehicle. He and Aeberhard sucked the fuel out of the system and cleaned the filters. Once they got it from the soda to the water, Aeberhard had to push it kilometers back to camp while Moses steered.
“It's a very, very dangerous place, Lake Natron,” says Cordey. “ Ultimately, without collaboration, you could come a cropper very, very easily. When you're working in our business, you do absolutely have to trust the capabilities of the person you're with.”
While filming the birds, Aeberhard operated from within a hide that looked like a miniature gazebo. In order to get closer to the birds, he would need something less conspicuous. In Yucatán, he had made mock-up flamingos with plywood. This time, Williams suggested printing them. Aeberhard did so and staked them in the mud. Soon, young birds — unapproachable the day before — were coming up to him and begging him for food.
Even more memorable than the beautiful shots of the crèche was the footage of marabou storks calmly skewering chicks out of the group and swallowing them whole. Aeberhard and Williams had expected predation but didn't anticipate anything this dramatic. The storks — or “ball-bag chin birds,” as Cordey remembers someone tweeting — are a terrifying sight, with long, sharp beaks and skin that looks as though it has been burned. “They're just absolutely disgusting,” says Rogers.
While Williams and Aeberhard were in Tanzania and Cordey in England, satellite phones and instant messaging apps were indispensable. Williams would send Cordey screenshots and clips of the footage.
“My mouth, frankly, was watering at the prospect,” says Cordey.
One of Cordey's shorthand phrases was “ring the changes,” which he would use when the team had captured enough footage of one particular type and should move on to a different angle or subject.
Sam Rogers knew that when he came to look at the flamingos footage, every shot would have been rated between 1 and 5, from poor to excellent. He wouldn't be shown anything lower than a 3. “Some of the shots that didn't make the cut would be the best shots in other shows,” he says.
Editing at the Silverback office, he enjoyed being able to pull in a wide range of people to canvas opinion. Cordey would give him room to work rather than breathing down his neck. After five or six days, Rogers would show Cordey a first cut in order to gauge his gut reaction. Some of the original footage of the storks was too gruesome. As a horror fan, Rogers had to be told to rein in the shots of them decapitating chicks and swinging their heads around.
It was Cordey who wrote the scripts for Attenborough. He knows the presenter's rhythms and made sure that Rogers left enough space in the edit for the words to breathe. At the last minute, Cordey decided to move the flamingos sequence from the end of the episode to the very beginning. “It was absolutely the right decision,” he says.
Cordey says there was a massive sigh of relief when the whole thing paid off: “There was so much against this sequence that it would have been easy just to say, ‘Let's not bother.’ But I knew that if it worked out, it was going to be absolutely the perfect sequence for this episode.” Williams watched the finished episode on the cinema screen in the Silverback office with a glass of wine and his girlfriend. “That was my little magic-achievement moment,” he says. Rogers watched it with his wife at home on a projector screen. “It just completely blew me away,” he says. “I'm so proud of it.”
On the horizon for the various members of the team is more of the same: Williams is working on a Silverback commission for Netflix, as are Cordey and Aeberhard. Especially after A Perfect Planet, Cordey is keenly aware that it is humans who are destabilizing the forces of nature, and that the solution to the problem lies in the natural world — in thermal energy, in solar energy, in wind energy. It will be this that continues to inform his work in the future.
As Attenborough says in the series' final episode, “We have the capacity and knowledge to stop the damage we're doing. But what we don't have is time.”
Dream Teams is a series from Inverse that takes a look back at the greatest team efforts of the 21st century and what they mean for our ability to collaborate in the future.