IJ Whyte

Kruger National Park, Skukuza 1350, South Africa

There is now ample evidence that in game reserves in which elephants are adequately protected from poaching their numbers will increase to the point where they begin to have negative impacts on biodiversity. Initially this may only affect the structural diversity of habitats but as elephant numbers continue to increase, some other species will be lost from the system. Generally, woodlands are changed to grasslands so that all species which are dependant upon woodland habitats may be extirpated.

The decision whether elephant numbers in any reserve should be limited must be based on the management priorities set for the reserve. If biodiversity is a priority, something must be done to limit the elephant population to a level at which their impacts will not have negative consequences for other species. And if the priorities for such reserves have not been clearly defined, management will be directionless and muddled.

In reserves in which biodiversity has been defined as the management priority, what options are available for managing elephants? Three only – translocation, contraception and culling. While the first two non-lethal options seem more ethically acceptable, they have their problems.

Translocation
Opportunities for translocations are now very limited. Most areas in Southern Africa that could potentially accommodate elephants now have them, while those that still can (e.g. Limpopo National Park in Mozambique), will not be able to take the numbers that need to be moved. While this method of population management may seem to be ethically acceptable it can seldom be established with certainty whether family units are moved intact or some members are left behind. The effects of such separation are not yet well understood.

Contraception
Current contraception technology is of limited value for controlling large populations. While porcine zona pellucida (pZP) vaccines have been shown to be effective and acceptable in elephants, oestrogen (oestradiol-17ß) implants caused behavioural aberrations and other unacceptable post-treatment effects. But regardless, the logistics of both techniques preclude their use. To stabilize an elephant population, 75% of all breeding females (i.e. 35% of the total population) must be constantly under treatment. These animals all require “boosters” at specific times, which means they must be individually locatable and therefore fitted with a radio collar. These requirements all push the financial and logistic costs to an unaffordable level for most conservation agencies.

Sterilization has the major drawback of irreversibility. Any population being regulated in this manner would be severely at risk from epidemics of either poaching or disease and its ability to recover would be greatly impaired if most of the adults (females or males) had been permanently sterilized.

A final problem with all contraception techniques is that they cannot reduce a population in the short term. Once a population has been stabilized by contraception, there will be a time lag before natural mortalities will eventually begin to reduce it.

Culling
Culling is the third option and, currently, is the only one that can solve the problems of over-abundance in a large population. However, it is an extremely emotive subject, particularly when applied to elephants. While culling elephants may be an anathema to some, it is usually seen by those concerned with the maintenance of biodiversity as a necessary evil – one which must be used in situations where translocation and contraception are not implementable.

The advantages of culling are that, in large populations, the over-population problem can be addressed successfully. Also, the processed by-products of culling (meat, hides, ivory, etc.) can be sold profitably to provide conservation activities, such as anti-poaching, with much needed funding. Disadvantages? a certain amount of disturbance to nearby related groups, the degree of which will depend on proximity and will be worst when a large group must be split. However, such disturbance is identical to that which accompanies translocation. The impacts come from the disturbances of the operation itself and from the longer-term effects of the loss of bond group or family members.

The major ethical question associated with culling is: Is it morally justifiable to kill elephants? Some Western cultures may find culling ethically unacceptable. But the question must be asked, whose ethics should apply? To a rural African with little access to protein, an average Westerner, or an animal rights campaigner, ethical elephant management will mean very different things.

While many believe that culling is not ethical, it must be understood that the culling option has to be weighed up against the losses of whole populations of other species. Loss of a species from a system will have its effects on biodiversity and the system’s food webs, and such a loss may even mean the complete extinction of that species. These species losses will occur if elephant numbers are not limited by some means. Therefore one must ask, is it ethical to allow species to be lost from a system when prevention is possible