Q&A: How innovation is helping to save species

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Controlled genetic management is helping conservationists rebuild endangered species whose wild populations have become too small and genetically fragile to recover naturally. In April, the Mount Kenya Wildlife Conservancy imported four male mountain bongos, Africa’s most endangered antelope species, to support controlled breeding and rebuild wild populations. 

• In this interview, Dr. Robert Aruho, the head of the conservancy, explains how controlled breeding techniques are being used to diversify the genetic pool and prepare captive-born bongos for life in the wild. He also discusses the science behind the rewilding process and how this method can be scaled for other species. 

• “To recover a population of such an important animal, you need a much stronger genetic base. With the four males, which are not related to our population, we can create four herds and four breeding opportunities going on at the same time,”  says Dr. Aruho, “The ultimate success is to see the mountain bongo population sustaining itself and extinction no longer possible in Kenya.”

More details

Q: Is there a challenge with the genetic diversity of the bongos in Kenya, and why did you have to import male bongos?

Yes. All mountain bongos in the world originally came from Kenya, specifically from the Aberdare ecosystem. Some were taken to America decades ago as part of conservation efforts.

The mountain bongo’s range was historically in Kenya and Uganda. In Kenya, they were mainly found in high-altitude forests such as Mount Kenya, the Aberdares, Mau, Eburu and Cherangani, while in Uganda they were found in Mount Elgon.

In the 1950s, there were close to 500 mountain bongos. But by the late 1960s, the population started dropping drastically because of intensive poaching pressure. Eventually, mountain bongos disappeared from some of their known habitats, including Mount Elgon, while populations in Kenya reduced significantly.

Currently, the only remaining wild population is in the Aberdare National Park, alongside the population recently reintroduced in Mount Kenya.

Between the 1960s and 1970s, the owners of the then Mount Kenya Game Ranch proposed to the Kenyan government that some bongos should be sent to zoos abroad as an insurance population. The concern was that if the species disappeared in Kenya, those animals could later support breeding and restoration programmes.

That prediction eventually came true. By 2004, mountain bongo numbers in Kenya had dropped to below 100 individuals, most of them in the Aberdares. It became difficult to capture animals from the wild for conservation breeding.

That same year, the Mount Kenya Wildlife Conservancy began a breeding programme using bongos imported from America. Since then, the programme has been successful, with the population in the conservancy now growing to over 100 individuals.

However, recovering a species like the mountain bongo requires a strong genetic base. Most of the animals in the breeding programme came from America and, after nearly two decades of breeding, there was a need for fresh genes to diversify the genetic pool.

The four imported males are not related to the current breeding population. This creates new breeding opportunities and strengthens the genetic diversity of the herd.

Q: How does the breeding programme work?

The breeding programme is carefully managed using detailed records.

All bongos are registered in an international studbook, which is a global record of every living mountain bongo held in conservation institutions. These records make it possible to know which animals are related and which are not.

Using that information, the conservancy pairs males and females that are genetically compatible but unrelated. The aim is to prevent inbreeding.

The four imported males will each be paired with unrelated females, creating four separate breeding lines at the same time.

Selection is based on factors such as genetic distance and mean kinship. Breeding is not random at this stage because the goal is to build a strong and healthy genetic population.

The conservancy also keeps long-term records stretching back to 1997.

Q: What would success look like for the mountain bongo conservation programme?

There are different levels of success.

For the importation project itself, the first success is for the animals to arrive safely in Kenya and settle at the Mount Kenya Wildlife Conservancy.

The second success is for them to adapt well to the environment.

The third success is to see them produce offspring.

The ultimate success is for those offspring to eventually join free-living populations in the wild.

At the national level, success would mean reaching a population level where the mountain bongo is no longer at risk of extinction. The target is a viable population of about 750 individuals.

When that happens, conservationists believe the species will have reached a stable population strong enough to sustain itself in Kenya, which is the mountain bongo’s endemic home.

Q: Are there plans to return more bongos to the wild?

Yes. A rewilding programme is already underway in Mount Kenya.

In 2022, the conservancy opened what it describes as the world’s first sanctuary dedicated specifically to the mountain bongo. Twenty bongos were introduced there, and the animals have already started breeding. Five calves have been born in the sanctuary so far.

Rewilding is a gradual and science-driven process because the animals are transitioning from human care to free living.

The conservancy selects animals based on several survival traits. These include their ability to browse and find food independently, resistance to disease and parasites, and their fear and flight response, which is important for escaping predators.

For females, strong maternal instincts are also considered essential.

Selected animals are first placed in a transition enclosure for about one and a half years. During that time, scientists monitor them closely and assess whether they meet all the required survival criteria.

Researchers collect detailed data on feeding behaviour, growth rates, health and behaviour. Only animals that demonstrate strong survival instincts are moved into the free-living sanctuary environment.

The process is heavily guided by science and long-term monitoring.