I enter the small South African town of Secunda after dark, and I'm greeted by the sight of four massive cooling towers and a lofty chimney illuminated by the lights of the world's largest coal liquefaction plant. You wouldn't expect to find much wildlife in this industrial landscape – but that's exactly what has brought me here. This unexpected place sustains the world's densest population of the elusive serval.
For those of you who have never heard of the African serval, you've been missing out. They don't get nearly as much press as their larger feline relatives, but the spotted carnivores are probably the most stunning (and definitely the sleekest) medium-sized cats on the continent. With their "satellite dish" ears and spring-like power in their back legs, they're masters of snuffing out small rodents and snapping up unwary birds across the wetlands and grasslands of sub-Saharan Africa.
But why has a serval population settled in this seemingly inhospitable spot, alongside a plant that churns out thousands of barrels of liquid fuel each day? What do they eat? What habitats do they use? These are all questions I've come here to answer.
As I arrive in Secunda, I get a call from Daan Loock, who heads up the Secunda Serval Research Project. "I hope you're ready for an early start tomorrow. These cats like to move early," he tells me.
Daan has been studying Secunda's servals for nearly five years, and was the first to propose a scientific study on their population at the vast Sasol Synfuels plant after seeing the cats on his daily drives in the area. Since then, he's set up some 100 camera traps across the plant's sprawling industrialised secondary zone to get a glimpse at how they're surviving here, what they're feeding on and whether they face any competition from rival carnivores.
At dawn, we set out in Daan's white Land Cruiser to locate one of the eight cats his team has radio-collared. "You can see how this habitat suits a serval perfectly. There's tons of cover, and the property is kept in good condition," he tells me as we drive. The grasslands and wetlands in this area, spanning some 6,000 hectares, are managed as game conservancies by the Sasol Synfuels Environmental Department.
Beyond the plant's security-controlled gate, we begin to see large reed beds, thick swathes of grass, and lots of small streams and dams, but for more than 90 minutes there's no sign of the servals we're tracking. We decide to try again in the late afternoon, and Daan leads me to check on one of the project's camera traps instead. As he flips through more than 600 images from just the last week or so, I'm taken aback by the sheer number of different species that feature in them. Vlei rats, guinea fowl, black-backed jackals and even mongooses – the wetlands surrounding the plant seem to be teeming with wildlife.
But it's the servals that are the most surprising residents here, and over the past couple of years the team has identified more than 100 different individuals. Daan shows me three different serval ID profiles, explaining how the team matches them up. "Each of these cats has a unique spot pattern, very similar to a human fingerprint. We match up each of the serval photographs to our existing database. It takes time but it's worth it."
The serval density near the plant is impressive, even when compared to famed wildernesses like the Ngorongoro Conservation Area in Tanzania, where the cats occur in high numbers. "Ngorongoro has about 20 to 30 cats per 100 square kilometres, but we've got more than two to three times that here. We've recorded the highest known density of servals anywhere on the planet," notes Daan.
The team chalks up these high numbers to an abundance of important prey like vlei rats, and a lack of large carnivores such as lions, leopards and hyenas, which have a reputation for killing servals.
By evening, we resume our serval-tracking mission, but after a few more hours, we realise we need a way of seeing through the thick reeds. In steps the Synfuels security manager, Johan Van Zyl, with a military-grade thermal camera system, which he uses for security monitoring at the plant. The camera can detect body heat from a distance of well over four kilometres away, and the servals, he tells us, often make a cameo.
It takes a bit of time, but soon the large camera (which sounds like something out of an action movie) is fitted to a 4x4 pickup, and we head out once more. Within minutes, we've spotted our first bit of wildlife: hundreds of climbing mice, hanging onto a vast reed bed and a porcupine foraging in an open section of the plant.
Then, finally, the highlight of the trip: a serval spotted from a few hundred metres away. We monitor the cat for well over an hour, and in that time it marks its territory (the camera even picks up its urine markings on some reeds!) and tries to initiate a hunt. There's even a quick flash of feline as the cat gets close enough to our vehicle for the spotlight to catch it.
For me, it's just a brief glimpse, but for Daan and his team, the work will likely continue for years to come. The project is the world's most in-depth study of this elusive cat species, and future research will focus on the interactions between servals and the local vlei rat population, as well as the size of the cats' home ranges and their use of this unusual habitat.
It's crucial work that will hopefully explain how the servals are managing not only to survive but to thrive here.
Top header image: Sasol Serval Research Project