By Tommy Sandri, 5th December 2023
The central highlands of Kenya, a region of rich agricultural lands, rolling hills and spectacular mountains, contain the country’s most populous areas and are crucial for its economy. But in addition to their immense value to human society, these mountains are also home to one of the most beautiful African mammals, and it is one you may well never have heard of. You are probably familiar with the term bongo in the context of the well-known Afro-Cuban drums, but did you know it is also the name of an antelope? Not unlike the paired drums, the antelope also comes in two variations, or subspecies: the western or lowland bongo, which is distributed across a broad range in Central and West Africa, and the eastern or mountain bongo, an elusive forest dweller endemic to a small area in the highland forests of Kenya.
The mountain bongo is the largest of the forest antelopes: males can weigh as much as 400 kg and reach a shoulder height of up to 128 cm. Its long, spiraled horns and its vibrant, chestnut-red coat adorned with contrasting white stripes and black markings make it a striking sight to behold. The species was once considered common throughout central Kenya, but a combination of habitat loss and disease—such as rinderpest, which is passed on by grazing cattle—has brought it to the very brink of extinction, and the subspecies is now categorized as Critically Endangered on the IUCN Red List.
In the early 2000s, this impressive antelope was thought to have almost disappeared from its last stronghold in the montane forests of central Kenya, until camera traps set up by a local NGO, the Bongo Surveillance Project, captured evidence of a herd still roaming the Aberdares and other nearby mountains. It was also thanks to these camera-trap efforts that a previously unknown population was discovered in the Maasai Mau region of the Mau Forest complex in western Kenya in 2013. The work of the Bongo Surveillance Project has provided crucial information for assessing the state of the mountain bongo’s remaining populations, but much is still unknown about this enigmatic species, and its Red List categorization is predominantly based on informed guesses from experienced people working in the field. Our research aimed to provide more rigorous information on this fascinating ungulate, to help assess its situation in the wild and inform effective conservation strategies.
Despite their striking coat patterns, studying mountain bongos in the wild is no easy task: this antelope is not only nocturnal, shy and elusive, it also occurs in areas with rough terrain that is difficult to access. However, one feature that helps researchers trying to unravel their ways of life is that individual bongos have unique markings on their flanks, chest and limbs. This means that each animal can be identified individually from photographs, a trick that enabled us to create a novel bongo identification system. The Bongo Surveillance Project, which has long been dedicated to the continuous surveillance and protection of the last remaining bongo herds, has generated extensive camera-trap footage. This—when combined with our new ID system—enabled us to analyse populations and estimate, for the first time, the population size of mountain bongos in the wild. This was no mean feat, and I spent so many hours sifting through bongo images and deciphering their coat patterns that I began dreaming of bongos and stripes (although, there are worse things one could dream of than bongos…)!
Although the hard work and long hours paid off in providing a scientifically robust population estimate, unfortunately the results did not bring good news. Our analysis confirms the critical situation faced by the subspecies, with no more than 50 individuals estimated to roam in two mountain areas in Kenya: the Aberdares and the Maasai Mau. The Maasai Mau forest area is not fully protected by a national park, placing the mountain bongos there in a particularly perilous situation.
The situation of this beautiful antelope in the wild is undoubtedly serious and we emphasize the need for further monitoring of these remnant populations. And yet, there is hope: thanks to a successful conservation breeding programme, there are over 700 mountain bongos in zoos and wildlife parks worldwide, and numerous projects are working towards the ultimate aim of reintroducing captive-bred individuals to the wild. By implementing conservation actions to reinforce existing populations and/or establish additional herds across the species’ range, we may yet succeed in preserving this majestic herbivore and ensure that it not only survives, but flourishes in the future.
The article ‘Population monitoring of a Critically Endangered antelope, the mountain bongo, using camera traps and a novel identification scheme’ is available open access in Oryx—The International Journal of Conservation.