New Science Reveals that Hunting and Killing Elephants is Not a Useful Tree-Protection Mechanism
By EMSF/ET - 26.
The shooting of elephants is often defended on the grounds that it provides conservation benefits that could not otherwise be achieved. For instance, not all conservation areas are amenable to photographic tourism, which means that they require other sources of funding to prevent the conversion of that wilderness landscape to agriculture whether that be through culling or trophy hunting. This argument is likely reflective of a false dichotomy, but that is not the subject of this article.
Another argument typically offered in favour of culling elephants is that elephants destroy large trees, which has negative cascading ecological effects. The natural order of vegetation is ostensibly upended, and other species suffer as a result.
Increasingly clear, however, is that seeing elephants as marauding tree-destroyers is unwarranted. Maintaining a landscape according to a benchmarked ‘carrying capacity’ for elephants is wrong-headed. A new scientific paper published this month by Dr Michelle Henley and Robin Cook in Koedoe throws cold water on the idea of carrying capacity as a useful concept for elephant management. Wilderness landscapes – in respect of elephants – have too often been managed in relation to an aesthetic ideal of what that landscape should look like, based on colonial depictions.
But this overlooks two important points:
- First, Rinderpest (a European born disease brought to Africa) led to herbivore decimation that would have allowed larger trees to dominate landscapes because there were fewer browsers.
- Second, the near-extermination of elephants through recreational colonial hunting would have led to large tree proliferation that was unlikely in a previously functional landscape. In other words, what we consider aesthetically desirable may be a far cry from what our pristine African wilderness looked like before colonisation.
Henley and Cook note that the biodiversity challenge for South Africa is to manage elephants in increasingly restricted spaces, where natural migratory corridors have been blocked by fences or other developments. They recognise the ecological importance of large trees – nesting sites for vultures, for instance. Big tree disappearance is likely a function of a multitude of complex factors, though, including that landscapes might be recovering from past distortions.
Elephants are ecosystem engineers that produce positive ecological effects through seed dispersal, compost deposition and tree disturbance by creating structural diversity. That is, unless they are over-concentrated in certain areas due to exogenous impositions on their movements.
An Elephant knocking over a tall tree is impressive and has - even if "still green" often given rise to wrong assumtions made by human onlookers. Studies show that the targeted tree is in most cases already destined to fall due to other factors.
A peculiar application of the ‘precautionary principle’ in South Africa’s Kruger National Park (KNP) has resulted in past attempts to control an input before a likely outcome has been scientifically established. Elephants have been culled, for instance, to maintain a static aesthetic state. But this appears to be entirely inappropriate for managing a dynamic landscape.
As Henley and Cook note: ‘The idea that the KNP can only maintain an elephant population of 7000 elephants has become entrenched in the minds of the general public, ignoring the concept that a carrying capacity of a static nature does not hold true in a complex ecological system’. Thankfully, the KNP’s management strategy has changed to ensure a gradient of elephant impacts across the system. ‘Carrying capacity’ has been debunked as an outdated agricultural concept, inapplicable for wildlife management in dynamic systems.
Most importantly, Henley and Cook’s review finds that elephants have been falsely accused as the prime large-tree destroyers. The evidence simply does not support the idea. For instance, the roan antelope enclosure was established within the Kruger around the same time as elephant culling occurred. Despite the culling to control elephant numbers, large Marula trees – an elephant favourite – still disappeared in the surrounding landscape while within the enclosure older Marulas also disappeared, albeit at a slower rate, due to natural senescence.
Other studies have revealed that elevation, soil, elephants and fire (in that order) have been found to be the best predictors of tree-fall rates over large spatial scales. Moreover, no reliable studies suggest that high elephant densities in Botswana’s Chobe National Park have caused irreversible damage to the ecosystem. The relationship between elephants and large trees is far more complex than commonly assumed. In fact, high impala densities have been largely attributed to the decline in the recruitment levels of large tree species within Chobe National Park.
Evaluating past elephant population management strategies, Henley and Cook show that culling is inappropriate, ethical questions aside. It does not produce the desired ecological effect. Elephant growth numbers escalate exponentially in the aftermath of culling. Pre-emptive culling also prohibits natural density regulatory mechanisms to come into play and prevents the attainment of density that results in dispersion. Dispersion is desirable, so preventing the catalyst for it is unwise management in open systems.
Most managers now reject the idea of culling as a management tool to save large trees. However, trophy hunting is still touted by some as a landscape management tool. Henley and Cook explicitly reject it as a management intervention:
‘… hunting is a highly selective activity, as bulls of particular age categories and with sought-after physical traits are targeted. For these reasons, hunting has not been listed as a population control method as it could result in undesirable skewed sex ratios and age structures within populations.’
The social disruption caused by shooting elephants can also make them dangerous to tourists, as they become more aggressive in the wake of trauma. It should therefore be strongly discouraged in areas reliant on photographic tourism. Shooting elephants, at least as a means of artificially producing a particular aesthetic is not a conservation solution.
The bottom line is that elephants are highly adaptive creatures that – provided they have sufficient space – change their consumption habits in response to changes in their environments. Adaptive management therefore calls for minimal intervention in large, open landscapes with functional ecological processes. In smaller reserves, translocation and immunocontraception are likely to prove superior to hunting or culling.