“We are bringing the boys home,” says Ngenoh Erick Kibet, a wildlife officer at the Mount Kenya Wildlife Conservancy, as he hears of the moment that a cargo plane carrying four mountain bongo has touched down on a wet runway at Jomo Kenyatta international airport.

The operation is the culmination of two weeks spent in Czechia, a first flight for Kibet, and a decades-long collective effort to rescue a species on the edge of extinction.

The mountain bongo may seem like any other antelope but no more than 100 have been counted in the wild. They are endemic to Kenya’s highland forests: the Aberdares, Mount Kenya, the Mau and the Eburu. For Kibet and Christine Gichohi, an animal keeper at the conservancy, spending time with these critically endangered antelopes on a daily basis is more than a job, it is key to ensuring that the species thrives.

The trip to Czechia was the first time Gichohi and Kibet had left Kenya. The four bongos they were bringing back – Fitz, Maue, Kudu and Bon64 – had been held in a quarantine facility at Safari Park Dvůr Králové, isolated from other animals and cared for indoors, their world condensed to an enclosed space. Gichohi and Kibet spent two weeks there, learning the animals’ routines, earning their trust and studying each bongo.

“Mountain bongos are the shiest antelopes,” Gichohi says. “Even if they are tamed, that shyness and curiosity will still be there.” Each of the four males has a distinct personality, and the keepers had to get to know them before the journey home could begin.

Maue is gentle, settled and the one who made everything easier. “He was very friendly and calm,” Kibet says. “You could get in where he was without any fear.” In the Czech facility, it was Maue who licked Kibet’s arm. It sounds like a small gesture. It was not.

Then there is Fitz – “the aggressive one”, Gichohi says. “He is one of the bongos that must be handled with a lot of care. He is not so friendly to humans.”

Kudu has trust issues. “You have to create a relationship with him before he allows you to roam around his enclosure,” Gichohi says. It was Kudu who gave them the most difficult time in Czechia.

Bon64, the youngest, is curious, prone to spooking, turning his feeding trough upside down and running from new faces. “Being curious is a good thing,” Gichohi says. “It will allow him to protect his territory and survive with other animals in the wild.”

The transfer was led by experts from England’s Chester Zoo and Safari Park Dvůr Králové in collaboration with the Kenya Wildlife Service (KWS) and the European Association of Zoos and Aquariums.

“The excitement was all over my face,” Kibet says of the moment he heard the plane had touched down in Nairobi. “I think I was the happiest person in the team.”

The journey to bring mountain bongos home started in 2004, when 18 individuals were repatriated from North American zoos to the Mount Kenya Wildlife Conservancy. These four males are part of a second wave, brought to strengthen the conservancy’s gene pool.

Gichohi and Kibet, who spend their days in the field and know each animal by name, temperament and feeding habit, are keenly aware of the fragile state of the species both in captivity and in the wild. But, says Kibet: “There is hope in the future, given that we are bringing the four boys to increase the gene pool within the facility we have.”

Gichohi has been watching the numbers shift since she first arrived at the conservancy. “I was born and raised around Mount Kenya forest,” she says. “Growing up, I have seen wild animals and the challenges we face as community members with wildlife.”

Kibet’s route into conservation began as a third-year university student when, during a field trip at the conservancy in 2017, he saw staff rushing across the grounds. He asked his lecturer what was happening. A bongo was unwell and was being attended to by vets.

“I saw how people set out to really care,” he says. He applied for an internship the following year. When a job opened up, he applied again. “What keeps me here is that I want to see these animals in the wild. Not my grandchildren seeing them in books.”

Meanwhile, the four bongos have been settling in. Kudu and Maue love digging at the ground, tipping their water up, marking their presence. “It’s a good sign,” Gichohi says, “showing they are now comfortable in the new environment.”

Thanks in part to the work of people such as Gichohi and Kibet, there are now 179 mountain bongos in the wild and captivity in Kenya, up from 150 in 2021. The conservancy’s captive herd, once 54 animals in 2021, had grown to 93 before the arrival of the four males. And recently, a 100th bongo calf was born at the conservancy, a moment that the organisation described not as a statistic but as proof that their efforts matter and the future of this species is viable.

“I am part of it,” Gichohi says, of the ongoing conservation effort. “Which is something that feels very good – to be part of something where you can see the impact while you are still alive.”