De-horning

Hornless rhinos?

What characterises a rhino? Some might say its huge size, immense power, thick legs, or prehistoric appearance, but I am sure the majority would say their horn. It is what symbolises a rhino, so why the sudden increase in dehorning over the past few years?

The answer is obvious: over the past few years there has been a shocking increase in rhino poaching. In 2011, in South Africa alone, 448 rhino were poached for their horns and as of mid-2012 over 300 have been poached. These horrific figures indicate the urgent need for both proactive and preventative measures to curtail the rhino poaching crisis. At a first glance, it would appear that by simply removing the horn the problem is solved; rhinos should be worthless to poachers. However, the issue is a lot more complicated than it first appears.

Namibia was the first country to use dehorning to protect rhinos from poaching. Between 1989 and the early 1990s, dehorning coupled with rapid improvements in security and funding for anti-poaching was perceived by stakeholders to have contributed significantly to reducing poaching losses. In Namibia, not a single dehorned rhino was poached.

There have been several other successful cases across Africa. Rhinos dehorned in recent years in certain Zimbabwe Lowveld conservancies appear to have 29.1% higher chance of surviving than horned animals. In Mpumalanga, South Africa, just over one-third of all the reserves’ rhinos (excluding Kruger NP)  have been dehorned, and out of the 33 rhinos killed from 2009-11, only one was a dehorned rhino.

Dehorning of a rhino bull - Zimbabwe

However, there are numerous cases where dehorning has proved insufficient to prevent rhinos from falling victim to poachers. For example, in Hwange National Park, Zimbabwe during the early 1990s, the majority of dehorned rhinos were killed just 12-18 months after being dehorned. In Zimbabwe’s Save Valley Conservancy, six newly dehorned rhinos were poached during January-August 2011 (one rhino was killed within 24 hours and another within five days of being dehorned).

For dehorning to be effective, it must be coupled with extensive anti-poaching security and monitoring efforts. With an absence of security, rhinos may continue to be poached regardless of whether they have been dehorned.

So why do poachers continue to target hornless rhinos? This is often attributed to the stub of horn that is left after removal. If the horn is cut too close to the germinal layer, this could damage the horn base and lead to deformed horn re-growth. Current dehorning is estimated to remove 90% and 93% of horn mass in male and female white rhinos respectively. So during any dehorning exercise a stub of horn will remain: although poaching is made less profitable, the sad reality is that poachers will still kill for a horn stub due to its high value.

Poachers may also kill dehorned rhinos out of vengeance. In Hwange NP, it was thought that poachers killed dehorned rhinos, to avoid tracking them again. Furthermore, if there is thick bush or hilly terrain poachers may not see if the rhino has an intact horn prior to shooting.

Horns grow back over time, with recent studies claiming that the re-growth of dehorned rhino horn appears faster than growth in non-dehorned rhinos. With the current severe poaching threat, experts recommend that rhinos should ideally be dehorned every 12-24 months in order to be an effective deterrent.

Dehorning is an intrusive procedure and, like any immobilisation, there is a risk to the rhino during the operation. While all efforts are taken to reduce the risk, there are sometimes veterinary complications while the animal is under anaesthetic that may result in death. The more frequently the rhinos are immobilised, the greater the risk.

In addition, dehorning is incredibly costly, due the effort of finding the animals and the costs associated with the immobilisation process, especially if needed on a recurrent basis. The actual cost depends on several factors, but current published estimates for dehorning range from US $620 (Kruger National Park) per animal to US$1,000 (private land). It is estimated that it would cost around US$5.8-8.8 million for a one-off dehorning of all the rhinos in Kruger National Park. (In practice, one could never hope to dehorn 100% of the population: some will successfully hide away and one should never dart a pregnant cow.)

An important consideration in the dehorning debate is whether rhinos actually need their horns. The evolutionary significance of horns in rhinos is not entirely clear, and may include mate choice or anti-predator defence. It is known that rhinos use their horns for several behavioural functions, including defending territories, defending calves from other rhinos and predators, maternal care (including guiding calves) and foraging behaviour, such as digging for water and breaking branches. Male rhinos use their horns during disputes over territory or dominance, so removal of the horn may undermine the ability of a particular bull to retain territory or status. On a positive note, dehorning has shown to reduce fighting-related mortalities among black rhinos in Zimbabwe. However dehorning may also decrease the value of rhinos, whether for photographic or hunting tourism or as a potential live sale.

The issue of dehorning leads on to another ‘thorny issue’ – what should be done with the horns? These could be destroyed; however they are more likely to be stockpiled by owners awaiting the potential legalisation of the trade. The current permit system for possessing, transporting and storing horn is considered to be onerous and presents a security risk through the leakage of information on the whereabouts of horns. This risk is emphasised by the fact that at least 38 horn-related thefts had occurred by mid-2009, including several armed robberies. In South Africa, there has been a substantial internal trade of rhino horn from natural mortalities and illegally dehorned rhinos and subsequent leakage of horns onto the international black market.

If rhinos are to be dehorned, it should be done in conjunction with a publicity drive to ensure that poachers are aware that the rhinos have been dehorned. If not, there may be a lag effect whereby poachers continue to target rhinos in the area. There is also the possibility that dehorning rhinos in one area simply transfers the risk to horned individuals in other areas.

Dehorning has its place in rhino conservation and, although not a stand-alone solution, recent successes demonstrate that, used alongside other methods, dehorning can be used to protect rhinos. Due to the invasive nature of dehorning, it should only be considered as a last resort under conditions of severe poaching threat. For example, although dehorning is not routinely practised in Kenya, its small population of Northern White Rhino is routinely dehorned due to the exceptional conservation value of being the last remaining individuals of the subspecies.

A first priority for all rhino conservationists should be to ensure adequate anti-poaching monitoring and security (including intelligence-gathering) to protect rhino populations, and only then should dehorning be considered, for is a rhino really a rhino without its horn?

How is dehorning carried out?

  • Rhinos are usually darted from a helicopter, but occasionally from the ground in smaller reserves
  • A pen is used to mark the point of removal – usually 7cm from the base of the front horn and 5cm from the base of the back horn
  • While under anaesthesia, a chainsaw or hand-saw is used to cut the horn off horizontally
  • Eyes and ears are covered to prevent noise / disturbance / damage from the saw
  • The stump is trimmed to remove excess horn at the base, then smoothed and covered with Stockholm tar to prevent cracking and drying

Further reading on dehorning

Click here to read the Endangered Wildlife Trust 2011 study on the dehorning of African rhinoceros as a tool to reduce the risk of poaching

Click here to read a 2013 paper by Raoul Du Toit and Natasha Anderson from the Lowveld Rhino Trust, whose research challenges some of the supposed consequences of dehorning

Click here to read 'Caught in the Crosshairs' a scienceline article investigating the dehorning debate

(40) Comments

  • Anonymous commenter
    10 February 2013, 20:51

    After a rhino is dehorned could a synthetic replacement horn be glued to the stump. If it was made in an unnatural colour it would be obvious to a poacher that it was not worth killing. There would be the potential to incorporate a tracking device into the replacement horn.

    Alternatively instead of dehorning the rhino, could a hole be drilled and a tracking device installed so that poached horns can be intercepted as they are smuggled out of the country.

  • Cathy Dean
    13 February 2013, 12:31

    The problem with sticking on a synthetic replacement is that horns regrow, at a rate of about 1 inch per year. These synthetic horns would fall off quite rapidly.

    And field programme managers can and do implant transmitters inside horns, that emit signals to those with receivers, with more and more checkpoints being added at ports and airports. The problem - as always - is cost: anaesthetising a rhino to implant a horn transmitter is around US$2,000 per animal, once all associated costs considered, and the batteries have a life of 2-3 years, necessitating pretty frequent repetition.

  • Anonymous commenter
    08 March 2013, 07:13

    When the poachers take the rhinos horns off, do the rhinos suffer? is it painful?

  • Cathy Dean
    08 March 2013, 09:55

    Try watching this video and then maybe you can answer your own question:
    http://www.youtube.com/watch?v=Q8PD-gsghBc

  • Anonymous commenter
    13 March 2013, 03:19

    instead of dehorning could you not just put the rhinos on a reserve and patrol that reserve?

  • Anonymous commenter
    14 April 2013, 01:09

    Why not use the chainsaw on the poachers instead of the Rhinos , I'm sure that would achieve better results .

  • Anonymous commenter
    28 April 2013, 14:19

    all rhinos are in reserves, however the Chinese are sending military helicopters, nothing is being done to educate the Chinese. American zoos which have 'stolen' black rhinos, putting them in nothing but glorified cages, should confer all $ profits back to saving the ones left in Africa.

  • Michelle
    29 April 2013, 05:34

    re: "and only then should dehorning be considered, for is a rhino really a rhino without its horn?"

    The rhino is absolutely still a rhino without its horn, especially if humanely removed.

    Just because we humans will need to adjust our mental image of a rhino, is no excuse not to pursue this conservation method (cost and hassle of dehorning aside.)

  • Andrew
    12 May 2013, 18:25

    A very well balanced and thought out article. The Namibia example shows that it can work provided other enforcement measures accompany it but there must surely be an element of merely moving the poachers elsewhere to rhinos that have not been de-horned. There are so many examples of rhinos being poached after de-horning that I wonder if the risk of the operation is too great and that we are better off leaving them as they are in all their glory. I think de-horning particularly threatened sub-populations such as the Northern White could be beneficial to take the pressure away from them and allow them to re-populate but de-horning on a mass scale would ultimately prove self-defeating. If all rhinos were de-horned then the poachers would simply continue and take what they can get. In fact, if a single rhino gives them a smaller volume of horn then they are more likely to poach more rhino to make up the difference. If supply falls due to the removing of de-horned horns then that would simply push up the price per gram and we are back to square one. De-horn in certain thought out and needed circumstances but otherwise let's concentrate efforts and resources to education programmes and security.

  • Rob Fausnaught
    31 May 2013, 22:23

    Where are the super-rich of the world? I know they donate extensively to African charities, especially Mr. Bill Gates. I understand he wants to help people, but what about the last few pristine areas that are still unchanged by mankind and the wild species they support? Once they are gone there is no going back. Humanity will ultimately benefit by protecting these last wild lands in perpetuity, when the immediate gains to be had by exploitation will be long gone. Without extreme drastic measures rhinos, tigers and other endangered wildlife is doomed to extinction in the wild. I can't even express the anger, sadness and shame knowing "my species" is responsible. I was in Tanzania 8 years ago and the only land that wasn't barren was protected areas off-limits to development. Seeing 2 white rhinos in Ngorongoro, even though they could only be seen clearly through a spotting scope, was a truly one of the most memorable moments of my life. I feel in my heart I have to do something...

  • Anonymous commenter
    01 June 2013, 07:42

    In the article you mentioned the pros & cons of dehorning but my question is this: Once the rhinos are dehorned are they still able to lead a normal life after losing their source of defence and/or way to find a mate?

  • Cathy Dean
    01 June 2013, 10:25

    Rhinos can lead a normal life after being dehorned - as long as they are in an area that does not have a dominant bull that has not been dehorned.

  • Anonymous commenter
    06 June 2013, 19:27

    So am I correct in saying that the best move would be to dehorn all the rhinos in the area?

  • Cathy Dean
    07 June 2013, 09:42

    To the last commenter:
    It's not practical or feasible to expect to dehorn all rhinos in any given area (other than very small reserves) in that: black rhinos are very elusive by nature; one should avoid darting a pregnant cow or one with a very young calf; the expense involved rules this out as an option for most park or reserve managers.

  • Kate Bowditch
    08 June 2013, 18:54

    If poachers (the bad guys) kill rhinos for their horns, and rangers (the good guys) anesthetize them for their horns, BOTH are taking the horns off Rhinos. I wonder what would happen if poachers were given the training to anesthetize rhinos for the for the horns instead of killing them. I KNOW it is counter-intuitive...but, poachers with no rhinos left are only going to look for something else to sell, whereas this crazy method might save rhinos...

  • Laura Adams
    19 June 2013, 17:38

    Hi Kate. Increasingly poachers do obtain drugs to anaesthetise rhinos before taking their horns. But rhinos usually die from their injuries, whether they were anaesthetised or not. Rhino horn is so valuable that poachers make sure they have each and every part of the horn. With de-horning of rhinos, a stub of horn is left.

  • Ian Harrison
    01 July 2013, 19:25

    Hi - I'd like to ask a question about the rhino horn market.
    Is it critical from the market's perspective that horns are complete ?
    Would a buyer purchase small pieces or horn or horn that has already been powdered ?
    In other words, is it important to a poacher to be able to get a whole horn that can be sold as whole horn without having had any processing done to it ?

  • Cathy Dean
    04 July 2013, 13:29

    Good question Ian. The short answer is that yes, entire rhino horns are more highly prized (and expensive), because it's harder to fake, and consumers think they're buying the real deal, whereas ground up horn could be diluted with other substances. Consumers (buying horn illegally of course) will buy the biggest piece they can afford: poor and desperate families with a relative at death's door would buy "rhino horn powder" if that is the only thing they could afford, but senior businessmen would want to buy a whole horn, as a sign of status and wealth.

  • Chris du Plessis
    11 July 2013, 20:57

    Some private reserves in South Africa have started injecting a substance in rhino horn which will make the end user very sick. I think this is an added avenue to pursue in the fight against poaching. But, unfortunately, the problem lies with corrupt officials and politicians. The idea which is forever being pushed by many that officially "harvested" horns be sold to flood the market is naïve wishful thinking. More than 25 000 elephants were poached in Africa in 2011 and still this atrocity continues. There are not enough rhinos in the whole world to satisfy the idiotic market.

  • Anonymous commenter
    26 July 2013, 16:28

    Surely the risk of losing a calf when darting a pregnant cow is lower than leaving the horn on to be poached?

  • Trolsmiter
    08 August 2013, 17:38

    the persons who made this website are the poachers you fools... one horn fetches 200,000USD... they are merely justifying themselves and deamonizing the others! You need hung right along side them.

  • Angela Cornick
    15 September 2013, 18:33

    I have just read this article and can't help but think the Chinese will not stop what they are doing no matter how well educated they are on the subject. I would have thought the additional cost of de-horning every couple of years would be well worth it for the African countries this effects due to the tourist trade it brings in. Such a huge problem with vast areas to patrol and monitor, more warders are needed who are paid a good wage and perhaps some kind of bonus if no animals are poached throughout the year - maybe an incentive then for the warders not to turn rogue or a blind eye to what is happening.

  • Mikey
    17 October 2013, 14:42

    This artical has a lot of problems. The Chinese have nothing to do with this. Chinese medicine had only limited use for Rhino horn, and it was removed from traditional Chinese pharmacopeia in the 1990s. And the reason why in Namibia, not a single dehorned rhino was poached in the late 1990s was because the price of Rhino horn was no more than $500/kg, and a whole horn wasn't worth $3000. Why poach a stub that is worth less than your rifle. However, today, mostly because of rumors in an increasingly affluent Vietnam (not China) that Rhino horn cures everything, particularly cancer, the current price is in excess of $100,000/kg. That's more than gold. That also means, just one good sized stump will pay for the poacher's helicopter. The economics of this does not make sense to argue about the cost of de-horning. A properly run de-horning and security program could not only fund itself, it could pay for any drop in tourist income to the host country. The price is so high the international community MUST allow governments the ability to put live-harvest horns into the market.

  • Anonymous commenter
    03 November 2013, 19:55

    Poachers won't have any more rhinos to poach if they are all extinct!

  • Anonymous commenter
    04 January 2014, 03:11

    We need to save these stupid looking animals.

  • Courtney
    11 January 2014, 08:27

    well thinking back at when I first say a Rhino. I said it was a unicorn! one day I would like to show my children in real life how a Rhino looks... but is that going to happen??? what animal would be next Elephant ?? Buffalo?? leopard?? or Lion?? we need to save our Rhinos before it is too late ...

  • kasper
    05 February 2014, 15:40

    i love rhinos

  • Anonymous commenter
    25 February 2014, 11:17

    does anyone have any idea about new ways to help stop poaching at all?

  • kim s
    06 March 2014, 22:05

    Has any considered starting a rhinoceros farm, where they raise them and humanely (relatively speaking here) farm the horns over the lifetime of the animal? I would think the farmer would make money while driving the prices down on the black market, making poaching less profitable and less appealing? Maybe a philanthropist like Ted Turner could be wooed...

  • Annie
    01 April 2014, 08:32

    I see that someone else has asked my question-what about making a rhino farm so that there is a supply and then (one hopes) less of an incentive ?

    I wish that there was some way of stopping the horns from growing back, or making them grow crumbly (or something like that)

  • Niraj Dubey
    30 April 2014, 12:09

    I suggest, we should start punishing buyers too by both heavy fine and imprisonment if they found buying a Rhino horn or its substance.

    However if it is at all required to sell Rhino horns from naturally dead Rhinos then every country with rhinos can make some certificate to be issues to the buyer that they have bought horns from only authentic source and not poachers. though in some countries it will be easy to do this cause of corruption so international community should have some kind of interference on watching the issued certificates to buyers from sellers.

  • Sandra Harvey
    12 June 2014, 04:51

    Why can't the horn that is removed through dehorning be sold on the market at a very low price so that poachers would be put out of business?
    Kind of like legalizing marijuana so the drug industry would be put out of a lot of their business.

  • Wayneroyce
    25 June 2014, 08:34

    Poachers are killing anti-poachers - in Africa, and that can continue for many years.
    Why not shift those human deaths to the ignorant country of demand.
    Somebody should please impregnate rhino horns with arsenic or C. botulinum and sneak them back into the black market supply line.
    It's just like putting methyl alcohol into methylated spirits to stop people drinking it. You drink enough you die.
    Governments are fine with it.
    Given time they will become fine with doing the same thing to Rhino horn.
    The word will get out relatively quickly, just like melamine in milk did.
    The markets demand will drop to a trickle & the remaining ignorami will have time to wake up.
    Save The Rhino!
    Tie the punishment into the crime.
    Like the law of gravity - you can't thumb your nose at it.
    Ignore it and pay the consequences.

  • sandb12
    29 July 2014, 15:38

    If the reserve is safely cutting off the horns to protect the rhinos from poaching anyway, why not sell the horn, undercut the black market prices, sell them legally, all profits go back to conservation instead of some shady guy, and over the years the problem could be solved. Sounds like win-win to me. What's wrong with this theory?

  • Anonymous commenter
    03 August 2014, 09:01

    I do not believe I am saying this 'legalise the sale of horns'. 'Certified horns' when the rhino is dehorned by the proper methods. Let the national parks benefit from the absurd medcicinal claims.

  • Anonymous commenter
    05 August 2014, 22:26

    Hi, two questions:

    Would it make sense to farm rhinos for their horns? You would keep them in a small reserve and breed them just for that purpose? Keep them safe, but not entirely wild.

    Where does the rhino horn myth come from?

    Thanks,

    Cat

  • CarolSchochFinger
    21 August 2014, 16:41

    Why not use the horns that are taken from the "dehorned rhinos" to scientifically disprove that they have any medicinal value what so ever. If the horns are so valuable, then a portion of them could be sold to pay for the study. Every buyer of Rhino horn should be given a mandatory community service sentence, that has to be fulfilled by either the buyer, or a member of his family, as a penalty for the buyer having bought rhino horn, which should be illegal everywhere. Only "authorized sellers" could sell rhino horn with impunity, and in this case, it would be those who harvest the horn for research, and to save them. All other seller should serve serious jail time. All remaining rhinos in the world, should be put into a fenced reserve, that has cameras, and alarms, and anyone caught poaching a rhino should receive the death penalty. The same with elephants and gorillas. We don't live in the jungle any more. The jungle is evaporating more quickly that a mud puddle in Miami. It's time to stop the extinctions before they take place.

  • Anonymous commenter
    21 August 2014, 20:58

    Imagine you were a rhino. You had your horn your whole life. Then one day you were tranqualized and woke up to your horn being cut off. Why are we focusing on the rhinos having horns as being the problem? WE ARE THE PROBLEM! The people!! The only "humane" solution is life behind bars for having anything to do with poaching. FOCUS ON THE POACHERS not the rhino. Go undercover on their ass.

  • Anonymous commenter
    08 September 2014, 10:35

    When you consider that humans have been breeding animals for special characteristics for thousands of years (consider all the varieties of domestic breeds of dogs and cats, for instance) perhaps the conservationists should get the genetic engineers in and start doing some genetic tuning to breed hornless rhinos. I see nothing impossible about this, although it may be difficult. This would get around many problems associated with horn re-growth (poaching for stump re-growth) and all the rest of it...

  • John
    19 September 2014, 13:29

    Why doesn't 'fake' rhino horn be created by a company, and supply thousands of these things with similar properties of a real horn. This would devalue the real horn and perhaps slow down the poaching. Would they still poach , if there was a steady stream of fake horn .

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