Dehorning Rhinos - A Necessary Evil

Then, silence and a slight ringing in the ears as the severed horn drops to the plastic sheet beneath the rhino’s sedated head. This is what they want, the poachers. The now useless lump of keratin, moments ago - the rhino’s most distinguishable feature. Noise builds again as the angle grinder begins to smoothen the edges of what horn remains, removing more of the precious horn in the process. Shards of keratin create a small cloud of dust around the horn. 6 cm of horn that grew back in the course of a year has been removed. Every little piece of horn is collected. Nothing is left behind. The plastic sheet and earplugs are removed. The people clear off, leaving the vet on his own and the gigantic beast is woken up again. A few moments pass, before the rhino has regained consciousness. It gets up abruptly and trots off into the bush. Another rhino successfully dehorned. We continue in search of the next rhino. Of the next horn to be removed.

Dehorning in itself is also not enough. It is not a stand-alone solution. It needs to be applied in combination with qualified antipoaching units conducting rigorous monitoring and patrols - 24/7 protection for the rhinos. For some reserves, the costs of having rhinos are outweighing the benefits, forcing them to sell their rhinos. But it is increasingly difficult to find reserves willing and able to take on the labour, stress and costs of protecting rhinos.

For rhino dehorning to be effective, it is necessary to dehorn all of a reserve’s rhinos. If only some are dehorned and the rest are left, the poachers will know. With the balance of risk and reward skewed in favour of reward, the poachers will attempt to get to the rhinos that still have their horns. Dehorned rhinos encountered along the way are likely killed to reduce the risk of wasting time tracking the wrong rhino, to send a message to the people in charge, or just out of spite. Thus, all the rhinos should be dehorned at the same time. As rhino horns continuously grow, it is necessary to repeat the operation every 18-24 months. In some of the more at-risk reserves, dehorning is an annual affair.

But what about the dehorned rhino? How does it affect them? It is a relatively new method. It started in Namibia in the 1980s and was later applied in both Zimbabwe and South Africa. With varying results and concerns. With lessons learned and procedures improved.

The procedure itself is invasive, risky and stressful. Everything possible is done to reduce the risk and stress. One example are the gigantic earplugs used to reduce the noise from the chainsaw. For some reason, rhinos are especially sensitive to the immobilisation drugs. The drugs can result in the unintentional death of the immobilised rhino. The reason why is unknown. Another layer of risk added onto the already vulnerable rhinos.

Then there are the horns themselves. Horns that have evolved for a reason through eons of adaptations to their surrounding environment. Rhino horns are multitools with a variety of behavioural functions, e.g. foraging such as digging for water and minerals, defence of place in hierarchy and territories, as well as defence against predators and other rhinos, and maternal care with guiding and teaching calves. How are these aspects affected when the horn is removed? Studies have shown that dehorning rhinos does not seem to have excessively adverse effects. Defence of territories and dominance were not affected. Neither was rate of calf mortality, intercalving periods, or population growth rates. However, there is a need for more extensive studies taking into consideration the differences between dehorned populations in terms of available space, intra- and interspecific population pressure, food availability, and feeding schemes, before the final verdict on the applicability and effectiveness of rhino dehorning can be made.

Dehorning does seem to work. Records kept by the renowned veterinary institute, Onderstepoort, confirms this. Dehorning is not be a permanent or long-term solution. It can work as a temporary solution in concurrence with other security efforts.