Momentum seems to be growing for re-opening an international trade in rhino horn, congruent with what seems an insatiable desire to monetise our remaining biodiversity.
This is exemplified by a letter published in one of the world’s foremost academic journals, Science, on 10 October 2024 , titled “Protect white rhinos by legalising horn trade”. The author, Martin Wikelski, is a formidable scientist. He has 42,783 citations to his name according to Google Scholar, and an h-index of 109.
These credentials clearly do not prevent the author from making untested assertions, which would be worth ignoring if scientists’ words did not carry so much weight. But they do, because the public expects that those with much learning should exhibit wisdom. Not everyone can be a scientist, so we sometimes rely heuristically on those who are. And thankfully academic freedom allows for retorts, one of which was published alongside the letter mentioned above.
Allow me to add a few of my own.
We teach philosophy undergraduates that an assertion is not an argument. An argument, at minimum, consists of premises and a conclusion. Whether the argument is strong or weak rests on the truthfulness of the premises, and the logic of ensuring that the conclusion follows. Failure to credibly substantiate premises warrants a red pen glaring, “assertion without substance”. This is designed to avoid students (who think they know everything)asserting opinion as fact or falling prey to a dizzying array of fallacies and biases.
Holding a position based on what other ‘authorities’ have said on the matter does not constitute an argument. Unfortunately, many scientists appear not to have been schooled in the philosophy of science. This led Oxford Mathematician John Lennox to quip that “not every statement made by a scientist is a scientific statement”. If a scientist makes wild assertions without evidence-based substantiation, the assertions remain just that.
What does this have to do with the question of whether a legal trade in rhino horn would work for conservation of the species or not?
First, we should note that Wikelski, in 660 articles that appear on Google Scholar under his profile, does not mention rhinos (at least in the titles of those articles) once. This does not disqualify him from commenting on rhino conservation, but the grounds for heuristic appeals to what Wikelski might think on the matter are absent. This places extra pressure on Wikelskito build substantive arguments that bear up under scrutiny, especially in a forum like Science.
Second, Wikelski casts aspersion on the idea that the 1977 international ban on trade in rhino horn worked, despite poaching numbers dropping formidably between 1977 and 2008. Itremains possible that recovering rhino numbers and the 1977 ban are merely correlated without causation. Nonetheless, it seems irresponsible, without showing that this is correlation without causation, to assert that “this long-standing policy [the ban], in which countries without rhinos impose bans on rhino-holding states, has not worked.”
Instead of carefully showing that the ban has not worked, Wikelski asserts “Legalising the rhino horn trade would improve conservation success.” Generously, we could say that his argument is partly substantiated by a premise that “rhino numbers had already increased before the ban was established, particularly in areas where private rhino guardianship was allowed, such as in South Africa.” That rhino numbers had started to increase before the ban does raise a sequence question.
Causation requires appropriate sequencing – A must precede B if A is to cause B. However, this does not solve the conundrum. It may be that the ban prevented any outward shift in the demand curve through a stigma effect, short-circuiting shocks that could otherwise have undermined species recovery. Moreover, the private ownership of rhino prior to the ban seemed to help initial growth recovery, but its success clearly wasn’t premised on being able to trade horn.
Wikelski references Ian Players’ book The White Rhino Saga in support of the idea of private ownership success. But that book contains zero debate over whether private ownership was the key or not; it simply states that rhino numbers went up on private reserves and elsewherefrom the early 70s onwards as a function of heroic translocation efforts. Those numbers did not go down after the 1977 ban (at least not until after 2009). This seems to support the argument that the ban perhaps wasn’t causal but was strongly complementary to rhino recovery.
Third, Wikelski articulates the sudden shock that hit white rhino numbers from 2010 (the poaching in South Africa started to ramp up in 2009) onwards due to a significant demand surge.
The numbers are reflected by province in the graph below:
Given the high number of deaths since 2010, Wikelski argues for legal trade along the following lines:
Are the premises defensible or plausible, and does the conclusion follow?
On the first, rhino horn is renewable, but that is hardly an argument to rhinos to breed rhinosintensively. The question is whether such breeding would satisfy or spur demand. We do not know, which is why the Science response letter rightly points out that this approach “carries substantial and unpredictable risks that could expedite the extinction of rhinos.” Farming of other species has had mixed results at best.
The best current research suggests that the most appropriate anti-poaching measures are, in descending order: de-horning, internal integrity testing among reserve staff, using K9 units to track and chase poachers, followed by camera detection technology.
These are all expensive interventions, though dehorning is the least expensive. The problem with dehorning is that wild rhinos need their horns – a rhino without a horn is hardly a rhino. This strongly suggests that the most sustainable approach is to radically drive down demand.
To do so, we need to know the specific, evolving, dynamics of demand for differentiated rhino horn products. Some portion of demand, probably on the high-price, inelastic end, explicitly wants evidence that horn is ‘wild-caught.’ This scuppers the weird argument that legalised supply, according to Wikelski, is the preferred consumer option.
On the second, the assertion is so wild as to be laughable. Making supply legal sends a strong signal to consumer markets that rhino horn is a legitimate and desirable product, which would undermine the stigma effects currently associated with consumption. As renewable as horn is, it does not grow on trees and seems highly unlikely to satisfy potentially expanding demand. Moreover, legal trade – especially in weakly institutionalised and high-corruption contexts – provides a laundering channel for illicit trade. Even well-resourced monitoring cannot keep up with the rapid evolution of illicit rhino horn products.
Breeding for legal horn trade is fundamentally more expensive than poaching
The risk, then, is that poaching would continue despite (or even because of) legal markets. Breeding is fundamentally more expensive than poaching, and the security costs associated with breeding would only increase if demand (re)exploded. Wikelski’s disclaimer that the horn should be carefully monitored assumes high-capacity law enforcement (and an ability to distinguish between legally and illegally procured horn) that simply does not exist.
Wikelski’s conclusion follow the premises, but the premises are simplistic, unsubstantiated and implausible. The Nuijten et al letter, by contrast, references a paper by Douglas Crookes and James Blignaut (which Wikelski oddly does not cite) that debunks the false dichotomy myth that the ‘ban didn’t work, therefore we should trade’. Their modelling results showed that “while it is optimal for game farms to harvest after 1.5 years, for poachers it is optimal to kill a rhino and harvest its horn, even at very low rotation intervals. This suggests that, even if a poacher encounters a dehorned rhino, it is still optimal to kill the rhino and take what is left of the stump. This casts further doubt on the effectiveness of a legalised trade…” Now that is an argument, built on sophisticated modelling and systems thinking, with no dubious premises and a conclusion that follows logically.
Original Source: 2024-11-12-why-a-legal-trade-in-rhino-horn-wont-work