Ears 'notched' in drive to boost Kenya's Rhino population

At Ngulia Rhino Sanctuary in Tsavo West, wildlife teams are carrying out one of Kenya’s most intensive identification operations for black rhinos.

Over the course of 15 days, more than 100 animals are being fitted with ear tags and digital transmitters, allowing rangers to track their movements in real time.

The process begins with locating and safely sedating each rhino.

Once immobilised, specialists notch both ears using a specific pattern of small cuts.

These patterns form a permanent visual code, allowing each animal to be recognised at distance.

Alongside the notches, roller ear tags and digital transmitters are added, creating a detailed record that includes the rhino’s age, sex, health history and movements.

Kenya Wildlife Service says the aim is to build an accurate database of individual rhinos.

This allows teams to trace family lines, monitor breeding success and detect any unusual changes in behaviour that may signal stress, injury or poaching risk.

The exercise is part of a wider national strategy to recover the black rhino, which is one of Africa’s most threatened mammals.

Although Kenya now has slightly more than 1,100 rhinos, they are spread across small, isolated populations. Ensuring genetic diversity requires animals to be moved carefully between conservancies.

Philip Muruthi, Vice President for species conservation and science at Africa Wildlife Foundation, says this level of identification is essential.

“The whole population of the country, the rhino metapopulation, composes of small populations that are scattered. And so, in order to maintain them in a genetically healthy population, the meta population, we’ve got to move individuals around. There’s also an aim in our national rhino management action plan and recovery plan, that we grow our population. So, there are now about a thousand and a hundred or so, and we aim to reach 2,000 rhinos by, say, 2037.”

Knowing which rhinos are related helps avoid inbreeding when new populations are created.

“What happens is you notch the ears, you produce a certain pattern on the right and left ear, so that when you see that individual, and using the coding that is used in rhino conservation, you can tell that is rhino so-and-so. So, it’s rhino Philip and you put them together with Janet, who is not their sister. So, when you move animals to establish new populations, as has happened many times in Kenya, you want to move individuals that are not so closely related, like sisters,” says Muruthi.

Ngulia Rhino Sanctuary itself is undergoing major expansion.

Kenya plans to increase the protected area from 92 square kilometres to 3,000 square kilometres by 2050.

Removing fencing and connecting landscapes through the Kenya Rhino Range expansion initiative is intended to reduce territorial pressure, a major limit on population growth.

“The reason it is a conservation concern, when you have more rhinos in a restricted space, is that the rate of increase of the population goes down, which you could say is equivalent to poaching, because you are losing certain individuals who would be there if the sanctuary was larger or the animals were in a larger place. So, it becomes a concern. That’s why Kenya is currently thinking about expansion of the rhino range. The constraint can come through social, because the groups exclude each other, they fight, and so you may even have deaths if the animals are so restricted together.”

Kenya Wildlife Service says the range expansion initiative aims to grow Kenya’s total rhino population from today’s 2,100 to around 3,900 by 2050.

The focus is on linking key strongholds such as the Tsavo ecosystem and Central Kenya, which hold some of the country’s most 'genetically important' rhinos.

When conservationists describe certain black rhinos as genetically important, they are referring to animals whose DNA represents older, rarer or less mixed bloodlines within the national population.

Kenya’s oldest rhino groups, especially those in the Tsavo ecosystem and in parts of Central Kenya, carry genetic traits that have become uncommon after decades of poaching and habitat loss.

Protecting and expanding the range for these rhinos helps ensure that the full genetic diversity of the species is preserved.

This diversity is crucial for long term resilience, because populations with broader genetic variation are better able to adapt to disease, environmental change and breeding pressures.

“So, rhinos don’t exist in isolation, but what is the value of a rhino? We’ve got sea rhinos as ecosystem engineers that keep the ecosystem healthy, not just for themselves, but for us humans and for other wildlife. So put rhinos in that perspective. It’s our heritage, so we don’t want to lose it. But don’t separate rhino conservation, say, from our aspirations of development. We will not develop if we have ecosystems that are not resilient, and those ecosystems will not be resilient if we don’t have key species such as rhino elephants and others,” says Muruthi.

Kenya’s black rhino population was once one of the strongest on the continent, with around 20,000 individuals in the 1960s.

By the early 1990s, widespread poaching had cut numbers to around 400.

The establishment of the Kenya Wildlife Service in 1989 and the creation of fenced sanctuaries helped stabilise and slowly rebuild the population.

Across Africa, numbers dropped from around 65,000 in the early 1970s to fewer than 2,500 later that decade, driven by demand for rhino horn and the expansion of organised wildlife crime.

The hope is that the ear notching programme will improve long term survival by creating better data, making it easier to move rhinos safely, and ensuring that expanded rangeland is used effectively.