By Dr Solomon Joubert
In the past few years the control of elephant numbers by means of culling as a valid option in the management of their populations was vigorously debated. Culling was strongly opposed by anti-culling parties. Ethical considerations and scientific accountability featured prominently in the debate.
The debate on the management, or otherwise, of elephant populations was characterised by rigid viewpoints steadfastly held by the opposing culling/anti-culling schools. The justification for elephant culling on the grounds of spatial constraints and impacts on biodiversity were vigorously countered by arguing lack of what could easily have been construed as philosophical reasons rather than concrete evidence. The arguments of the anti-culling lobbyists were further reinforced by the introduction of the concept of ‘meta-populations’, i.e. populations extending over vast (regional) areas with unconstrained spatial and temporal distribution possibilities.
The debate was eventually concluded with the acceptance of a set of management options on a national level, designed to meet local demands. These policy guidelines make provision for translocations, culling and almost any other innovations to harmonise general ecological interests and those of elephant populations.
Though the sentiments and viewpoints of the two camps largely remain, the debate has been settled and offers the opportunity for managers and researchers to consider the areas still under dispute and to probe a rational way forward. This phase, more than ever, will call for integrity, open-mindedness and an honest approach towards rational decision-making. Disputes and the seeking of solutions can no longer revolve around petty personal arguments but needs to take into account that it is the Kruger National Park, and its intrinsic natural values, that are at stake.
On 3 May 2010 the author and Dr Sam Ferreira, ecologist responsible for the management of large mammals and attached to the Research Section at Skukuza, Kruger National Park, had the opportunity of meeting and discussing various aspects of elephant management in some depth. The request for the meeting was prompted by statements that Dr Ferreira was reported to have made during an address at a research meeting at Skukuza during March. Amongst others, these were:
- it was not possible, without substantial bias, to census elephants;
- the management of the elephant population would no longer be based on numbers but would be ‘event driven’;
- the spike in the reproductive rate of the KNP elephant population was in reaction to the culling programme (which was terminated in 1995), and
- if left to increase the elephant population would eventually level off and maintain a stable density (ostensibly in harmony with other components of the ecosystem).
Though from two opposing camps the discussions were relaxed, open and constructive.
In compiling this report I have also taken the liberty of inviting comments on the draft from Dr Ian Whyte, a former research officer responsible for research on elephants in the Park. Where relevant his comments have been referred to in the text and included herewith as Appendix 1.
At the end of his long and illustrious career as the first Warden of the KNP Stevenson-Hamilton (1947) expressed the following warning: “… it is so easy to misunderstand the factors governing the actions and reactions of wild creatures living under natural conditions. Man, today, has such absolute power over the existences of other creatures of the earth,that any action taken as the result of inaccurate observations, or faulty deductions, may not only cause irreparable mischief, but may defeat the very interests which it is intended to serve.”
During his term of office Stevenson-Hamilton identified cyclical rhythms in the rainfall pattern (subsequently confirmed by long-term data sets). Furthermore, he was also able to relate associated changes in the vegetation and animal populations in response to the rainfall fluctuations. These cyclical rhythms also included the close relationship between herbivores, parasites and carnivores. Based on these harmonious interactions he concluded that “… where any attempt is being made to preserve natural conditions it is always wisest to let Nature carry matters out in her own way and to interfere as little as possible.”
After formal research started in the KNP in the early 1950’s considerable pressure came to bear on the young fledgling research section to provide answers to the pressing problems of the day, i.e. the role of carnivores, in particular lion; the role of veld fires and the spatial and temporal requirements of the Central Disrict’s western boundary animal populations, in anticipation of the erection of a fence to curb the spread of Foot-and-mouth disease.
A series of successive drought years during the 1960’s and early 1970’s with a concomitant surge in the numbers of several high density species, notably wildebeest, zebra, impala, elephant and buffalo, led to the institution of culling operations of all these species. An upswing in the rainfall cycle during the mid and latter half of the 1970’s, especially 1973 to 1978, into the early 1980’s resulted in dense swards of grass, a fragmentation and decline of the populations dependent on short grass (wildebeest, zebra and impala) and a notion that the large carnivores, especially lion and spotted hyaena, played an important role in the decline of these species. This ultimately led to a campaign to reduce the numbers of these predators in selected areas. These two extremes in the rainfall cycle largely ushered in an era of active intervention, leading to an intensification of water provision, adjustments to the veld burning programme and the artificial manipulation of animal populations.
During the high rainfall phase of the climatic cycle (1970’s to early 1980’s) culling of most of the populations initiated in the 1960’s was terminated. At this time the research programme of the KNP was also re-organised and defined as a study and analysis of the ecosystem, with detailed consideration of the dynamic nature and inter-dependency of the individual components comprising the system and therefore also to serve as a basis for the implementation (and evaluation) of management strategies as necessitated by circumstances. This holistic approach represented a major redirection of the research effort and attitude towards management. The primary research objective was further underpinned by the adoption of the philosophy that ecosystems (in fact, individual populations as well) were akin to living organisms, with “life” defined as the spontaneously dynamic symbiosis of interacting and interdependent systems, each having its own composition and structure, with the inherent capability of reproducing and perpetuating.
During this era the closure of artificial water points was initiated, fire management was returned to a totally natural regime, culling of all but elephant and buffalo populations was terminated and the monitoring of the climate, vegetation and animal populations was intensified. Essentially, this implied the adoption of a philosophy that natural processes would be allowed to take their course as far as this was possible without human (unnatural) interference.
For most part the KNP was regarded large enough to accommodate most natural processes, with the exception of the population cycles of elephant. However, by the end of 1994 the situation pertaining to buffalo and hippo had not been finally settled: in the case of the former their population increases under favourable conditions (high rainfall) was of such a magnitude that it was believed that they could achieve densities that could have a negative impact on tourists when their populations crashed during periods of drought (buffalo being vulnerable to droughts) and in the case of the latter the effect of the plight of the perennial rivers on their populations was still uncertain (though culling had been terminated)
A universally accepted principle in the management of wild (and domestic) animals is the control of the numbers of those populations that are regarded as a threat to the sustainability of their resources, in particular where these are shared with other species. An underlying consideration where management options of this nature are contemplated, is the spatial constraints imposed on the animals in question. In this respect, it is not only the direct impact of the animals on their food resource which is of importance but also the impact on the spatial and temporal requirements of all the species involved (both the targeted species as well as associated species).
By any standards of land management the 2 million hectares encompassing the KNP represents a vast area. However, in terms of the spatial and temporal requirements of elephants it was not regarded as sufficient to accommodate their population cycles. Based on this principle the most appropriate strategy accepted to manage their population was to control their numbers. It was, however, also acknowledged that the cumulative effects of constant population pressure would eventually result in destructive impacts on their habitats. This implied severe management challenges. As all natural processes function in cycles and the ‘lebensraum’ of the KNP was considered too limited to accommodate those of the elephant population their cycles had to be imposed artificially. Attempts in this respect included concentrating culling operations in one region of the Park for a number of years and then shifting the focus to another, thereby lowering densities in one area and allowing increases in the other. An acknowledged flaw in this approach was the limited time allowed for the fluctuations (initially suggested 3 years of concentrated culling followed by 3 years of no culling). No conclusive results from this approach could be reached before a moratorium was placed on elephant culling.
In 1995 the moratorium was placed on elephant culling in the KNP, a moratorium that has remained intact ever since. During this period the elephant population increased from 7 500 to its present level of around 15 000.
Currently the mission for the Kruger Park reads as follows: in keeping with the SANParks mission, Kruger National Park strives to maintain biodiversity in all its natural facets and fluxes, to provide human benefits and build a strong constituency and preserve as far as possible the wilderness qualities and cultural resources associated with the Park. According to the SANParks website this mission statement contains three qualifications. Of ecological importance is the inclusion of structure, function and composition under the concept of “natural”.
Essentially, the philosophical approach towards the management of the Park makes provision for the maintenance of the intrinsic qualities of the composition, structure and dynamic processes of the ecosystems in their most natural state possible.
During the elephant debate much was made of the lack of a sound scientific basis for determining the most appropriate management strategy for the elephant population. The Kruger Park’s view was that the elephant population was carefully monitored, research projects had been undertaken (and were ongoing) on all aspects of their population ecology, that there was no evidence of any negative affects on the population after 30 years of culling and that management objectives were effectively achieved.
The ‘new’ approach towards the management of the elephant population may then be viewed against this background.
What had been conveyed to me was that a statement had been made to the effect that elephants could not be censused from the air. This was due to the fact that not all the animals could be spotted. A slide was apparently screened on which only some 5 individuals out of a total of about 9 could be spotted by the audience. This was held as proof that elephants could not be accurately counted and that any attempt at a census would result in unacceptably high bias. Dr Ferreira conceded that he has not undertaken a helicopter census of elephants.
The above perception was somewhat refuted by Dr Ferreira and the discussion revolved around concepts such as accuracy and precision.
I joined Dr U de V Pienaar’s helicopter census team from its inception in 1966 and participated annually until 1986. The major features of the census were the following:
- it followed a standardised process, i.e. covered the entire Park by means of fixed routes and at the same time of the year;
- it was undertaken from mid-August to mid-September, a period coinciding with the driest time of the year when surface water resources were restricted, deciduous trees had lost their leaves, visibility was at a premium and the animals were most concentrated;
- the census team consisted of 4 observers, the pilot and an observer/navigator in the front seats and an observer/photographer (for many years primarily my role) and an additional observer, usually the section ranger, on the back seats.
- the only factor over which there could be little, or no, control, was the weather. Poor weather conditions, especially low cloud and cold winds associated with cold fronts, could negatively impact on visibility and therefore result in some animals being missed. Such conditions at the end of the winter season are, however, infrequent and usually do not last more than a day or two.
Elephants are easily spotted from the air in virtually all the landscape types of the Park. There are no extensive evergreen forests or closed-canopy woodlands of any consequence where it would be difficult to spot elephants. In addition, elephants are generally wary of the whine of the turbine engines of a helicopter and move when approached, thereby making spotting easier.
When breeding herds of elephants are approached they generally bunch together and are difficult to count. However, with some deft manoeuvring of the helicopter the herds are easily scattered and the herd animals can then be counted to the last individual. Bulls pose no problem. In this way a highly accurate count of all the elephants spotted can be obtained. It cannot readily be estimated/guessed how many elephants are missed during the census though factors such as maximum visibility, restricted water resources and the design of the census routes contributed to a high likelihood of spotting the animals. It is confidently believed that for most years very few animals were missed and that the accuracy of the census results was high (see Ian Whyte: comment 1).
To obtain a count from which statistically determined confidence limits can be estimated at least three counts need to be completed, preferably in quick succession. This would not be financially feasible nor practical in terms of the entire Park. However, if precision is really such a high priority repeat sample counts in each of the 4 regions of the Park could be undertaken in conjunction with the annual census. This could be financially and practically possible and probably required for only one year. On the other hand, the highly comparable census totals for the Park over more than 40 years should surely instill enough confidence to render them scientifically accountable! At least, the results reveal a high degree of repeatability – an aspect which is also of crucial importance.
The question of the accuracy and precision of the census results is an aspect that received much consideration over the years and is addressed in the respective census reports (in particular, refer to the attached census report by Ian Whyte, Scientific Report 06/2007).
Censusing wild animal populations includes data collected on population trends, distribution patterns and social organization structures (plus a host of important associated information). As such, censusing animal populations remains one of the most essential support projects in wildlife management. Its value in terms of monitoring and interpreting ecosystems should not be underestimated!
Censusing may even have quite unexpected outcomes. In this respect the following interesting bit of information recently came to my notice from two quite different sources: a herd of sable antelope (apparently 30-something) were released into a large enclosure in the Marakele National Park. In an aerial census of the enclosure only something like 3 animals were counted. The first reaction was to deride the census figure (rather heftily, I believe); a repeat census yielded the same figure. It was only later discovered that poachers had entered the enclosure, caught the bulk of the sable and made off with them!
On an aside: I believe that buffalo herds are no longer photographed as part of the census but their numbers merely ‘estimated’. As incredible as this may sound, can it possibly be true?!
And as far as the other large herbivores are concerned: personally I do not believe that the time, manpower, money and effort put into the ‘distance sampling’ method of censusing the other large herbivores is of any value to the Park. The initiators of the method, Drs Anderson and Burnham of the Colorado State University, USA, were in the Park, taken up in the aircraft for a simulated count and advised us that the method was not suitable for the Park. I have on occasion written to Dr Mabunda and suggested that it is time for a proper census to be done of all the large herbivores of the Park, to the same standards as those done earlier and I feel the need to repeat this suggestion again, as a matter of urgency.
‘Event-driven’ elephant management
I hope my interpretation of ‘event-driven’ is not too simplistic but as I see it this mainly implies that cues are derived from the level of utilization of the vegetation and that impacts exceeding predetermined ‘thresholds of concern’ need to be addressed. If this is correct I have certain areas of concern that I would like to raise:
- Dr Ferreira intimated that the Crocodile River area needs to be addressed. What I would like to know is: how was this determined and what has made it a higher priority than several other areas that I am aware of? Is any report/publication available which details the criteria to be applied to determine areas of concern and, in this particular case, what is(are) the motivation(s) given to select this area?
- In 1988 a former botanist of the Park, Albert Viljoen, published a paper in which it was shown that 93.4% per ha of the large trees (mainly knobthorn and marula) on the basalt plains south-east of Satara had disappeared between 1944 and 1981. Similarly, 49.6% of the trees (per ha) on the basalt plains between Lower Sabie and Crocodile Bridge had disappeared in the corresponding period. Has any follow-up work been done on this?
- To determine the events, and their intensity, to guide decisions on elephant management automatically implies that considerable effort will have to go into vegetation monitoring and assessments. In this respect questions arise such as: does the Kruger Park even have a botanist on its staff (as far as I have it no-one has been appointed to replace Holger Eckhardt, who resigned some two years ago!); have any analyses been done of the large number of fixed-point photographs (roughly 500) taken since 1977, or the large-scale aerial photo transects (more than 120) taken since 1981 (are they still being taken?); or the effects of the out-of-season veld fire programme presently implemented? How will these projects be undertaken if research officers, as incredulous as this may be, are restricted to only 30 days field work per annum? I believe there is a student analysing vegetation trends from satellite images but whether this will be sufficient (detailed enough) to give guidance on elephant management strategies is doubtful, at best.
The big question is: can the Kruger Park really convince the scientific and public audiences that the defining and prioritising of the ‘events’ to serve as guidelines for the implementation of elephant management strategies are, indeed, scientifically accountable? The counter-question is even more to the point: can the option of no-culling be justified while there is an apparent total lack of research capacity to cope with surveys to determine their impacts?
Areas heavily utilized by elephants, to the point where some management intervention is required, implies that those areas are attractive to elephants. By what manner and means are elephants going to be denied access to the areas, for how long and where will they be going to in the meantime? Have these practicalities been addressed? Is culling regarded as an option?
Spatial and temporal considerations
Spatial and temporal aspects play a vital role in the health of all animal populations and are intrinsic components of natural processes. Disruptions of the spatial and temporal rhythms have had severe impacts on several populations of the Park, e.g. the erection of the western boundary fence of the Central District that severed the migration routes of especially wildebeest and zebra and caused major collapses in these two populations. Similar disruptions have resulted in the local extinction of roan antelope and also affected eland, amongst others.
Spatial and temporal considerations, in fact, have been integral in formulating the principle that provided direction in deciding the justification, or otherwise, for the manipulation of animal populations. In cases where it was believed that the full population cycles of species could be accommodated in harmony with the fluctuations imposed on the other components of the ecosystem by the medium (20 year) climatic cycle, and without being affected by any man-induced disturbances, there was no justification to interfere with those populations. This led to the termination of culling in all but the elephant and buffalo populations. In the case of these species it was believed that the spatial constraints of the Park were severe enough to induce artificially high densities, to the ultimate detriment of the other components of the ecosystems. This ‘ultimate detriment’ was interpreted as artificially induced disturbances to the structure and composition of the other components, e.g. vegetation and animal populations (including species mix, numerical status and spatial and temporal disruptions). These effects would inevitably also affect other taxa, such as insects, reptiles, birds and small mammals. Artificially high densities of species constrained by spatial limitations could, therefore, have an impact on the total biodiversity of the Park.
Elephant, obviously, fell within this latter category. They could adapt to virtually all the habitats in the Park, their population trends were not affected by the medium term climatic cycles and they were highly competitive for the vital resources of food and water. From the history of the population trends it was also obvious that the Park was too small to accommodate their expanding population. To address this situation it was deemed imperative that some form of control of their numbers had to be exercised. The only option was to dispense with what was considered to be excess numbers. This was achieved through live translocations and culling. In this manner a remarkable level of control could be exerted over the population.
One of the fundamentally important attributes of all forms of ‘life’, at whatever level of organisation – whether at individual, population or ecosystem level, is that all functions (natural processes) are fulfilled by way of rhythmic cycles. The elephant population is no exception and one of the major challenges in the management of elephants was to find a way of imposing such cycles on the population. This is obviously a largely impossible task, considering that elephant population cycles, according to the best data sets, take anything between 200 and 400 years to complete. Nevertheless, the consequences of this are that elephant at stable levels probably exert a greater cumulative impact on the environment than heavy impact over a relatively short period, a collapse in the population and then a relatively long period (several medium term climatic cycles) for the habitats and associated species to recover.
Water provision in the Park has come a long way, since the early 1930’s. Essentially, the underlying motivation for providing artificial water points was to try and achieve larger numbers of animals (for the sake of tourists) by enticing them to waterless areas with sufficient, under-utilized grazing. There were also a number of additional motivations, inter alia, to compensate for the loss of natural resources with the erection of the western boundary fence, to safeguard rare herbivores and endangered aquatic species and to provide resources for periods of drought, especially after the Park was fenced.
The water provision programme progressed slowly up to the early 1960’s after which it gained some momentum. However, even at this early stage it was acknowledged that especially some injudiciously placed dams were defeating their object and rather causing problems through disruptions to the spatial and temporal cycles of some grazers.
Following a number of protracted drought years during the 1960’s and early 1970’s the water provision programme was stepped up during the 1970’s and early 1980’s. This coincided with an especially wet phase of the climatic cycle which ended in 1982/83. In spite of the numerous new dams and windmill water points that were provided natural water resources in the form of pans, seasonal watercourses, springs and the perennial rivers provided extensive and superfluous surface water. Then came the series of drought years from 1983 to 1992 which was the only period that the artificial water points served any real purpose before the rainfall pattern again improved during the mid-1990’s.
In the accompanying table the census results for various species is given at the end of the 1960/70’s and 1980/90’s droughts. These periods were quite similar in duration and intensity and though the census results were obtained from different methods the results show a remarkable similarity in the populations at the peak of the droughts – this in spite of all the water that was provided (zebra and roan are exceptions due to reasons not of relevance here). I do not think it is unreasonable to conclude that the artificial water resources played a very limited, if any, role in sustaining the populations through the drought or influencing shifts in distribution patterns.
Much of the new approach towards the management of the elephant population is being attributed to the role that the artificial water points have had on the distribution of the elephants. The question that arises is: why would elephants be an exception to all the other species? I am in total agreement with the closure of injudiciously placed water points (having personally closed the first 12) but think that some of the arguments based on the influence of water on elephants need to be reconsidered.
Table 1: Comparative totals for a number of herbivore populations at the end of the 1960/70’s and 1980/90’s low rainfall periods in the Kruger Park and the peaks of the populations in the intermittent (high rainfall) period.
|Impala||147 300||98 513||124 284|
|Wildebeest||12 557||12 738||14 603|
|Zebra||16 890||29 463||32 819|
|Giraffe||3 647||4 610||4 990|
|Kudu||4 990||3 281||10 760|
|Waterbuck||2 490||1 442||4 044|
|Sable antelope||1 030||883||2 240|
|Buffalo||19 735||15 253||29 707|
|Warthog||2 152||720||3 820|
Fire entered the discussion by way of my concern about the lack of vegetation monitoring. Not only elephants have an impact on the vegetation but also veld fires. At this stage it is apparent that nothing is being done to monitor the effects of what may be regarded as a highly unnatural fire regime. I am not sure whether the field rangers are still responsible for veld condition assessments, which could go some way towards monitoring.
I do, however, find it extremely strange that the Park justifies the closing of artificial water points to comply with a more natural situation but applies a fire policy that flies in the face of its mission statement to “maintain biodiversity in all its natural facets and fluxes …” Fire cannot be ignored as a very important natural process but its present mismanagement places a question mark over any other attempts to convince me that the Park is serious about abiding by the ‘facets and fluxes’ of nature.
Arguments I have heard in support of the present policy are to ‘create diversity’ and to simulate fires applied by rural communities over the past number of centuries. Neither of these arguments are relevant: on what basis can the Park justify its claim of ‘creating diversity’ in direct contradiction to natural processes, and why select one aspect of land use from earlier times and not all the other? Why not also try to simulate the effect bygone settlements had on the environment, their monopolisation (and poisoning) of water holes or their impacts on herbivores and carnivores?
The extent, intensity and effect of lightning fires are not only dictated by the fuel load but also by the prevailing conditions at the time of the fires, i.e. season, time of day (usually late afternoon) and atmospheric conditions such as temperature, humidity, wind, nitrogen fixation, etc. Lightning fires are frequently followed shortly after ignition by rain. This creates natural diversity in harmony with all the other natural processes. Of course, in times of high rainfall and the accumulation of heavy fuel loads fires can be severe, fully in accordance with the natural flexes and fluxes of the ecosystems. Natural fires usually occur during spring or early summer and in this way preclude burnt areas from exposure to prolonged high ambient temperatures and other factors that could negatively affect the vegetation, such as concentrations of short grass grazers at a time that grass growth is retarded. Such fires could also upset the established spatial and temporal utilisation of rangeland by herbivores.
Reproductive ‘spike’ of elephants in response to culling
Since the mid-1960’s when elephant censuses were initiated the recorded calf percentages have remained remarkably stable. The only exceptions were 1967 and 1995 when they were 11.3% and 10.1% respectively. In both cases this could most likely be attributed to observer bias as the classification of calves under a year of age remains a rather subjective judgement and largely depends on the experience of the observer(s). In all other cases the percentages are of a very similar order, in spite of some fluctuations. From the recorded percentages there do not appear to be any indications that the reproductive performance of the elephant population has been affected by fluctuations in the medium term rainfall cycles, termination of culling or any other influences on the population. On what basis the ‘spike’ in reproduction is founded is unclear and suspect at best (see Ian Whyte: comment 2).
Elephant population approaching its asymptote
Based on the results of recent census data the claim was made that there are “early signals” that the elephant population growth curve is reaching its peak. This supposedly implies that the population is reaching a stable level at which it will be in harmony with the other components of the ecosystems. It should, however, be pointed out that “early signals” are not established fact and therefore not scientifically accountable.
It is accepted that the opening of new rangelands adjoining the Park for occupation by elephants will relieve the Park of some of its elephant pressure and should be reflected in the census figures. It is known that a large number of elephants emigrated to the ‘vacuum’ created by the Sabi Sand Wildtuin (SSW) with the dismantling of the western boundary fence (in contrast to this, a similar emigration to the Associate Private Nature Reserves, where there had already been an established population, did not take place). A similar situation to that of the SSW could be expected in the opening of the transfrontier park, which includes much of the erstwhile traditional range of at least some of the elephant clans in the northern reaches of the Park. The elephant population trend should, therefore, also take this into consideration.
The notion that elephant populations could reach some state of stable population level is also highly debatable. The universal phenomenon of all natural processes taking place in the form of rhythmical cycles has already been alluded to. The elephant population is no exception and it can be expected to build up to densities where it could have severe impacts on the environment and all that is associated with it, collapse and then slowly build up again. And even if it is kept at a stable level the problem of the cumulative impacts of elephant over time will exceed those of relatively short term exposure to high impact followed by the advantage of several phases in the rainfall cycles for the regeneration and rehabilitation of the environment. The question remains whether the elephant population can be allowed to reach the stage where it will collapse due to the exhaustion of one or both of its vital resources (food and water) (see Ian Whyte: comments 3 & 4).
To create greater possibilities to meet the spatial and temporal requirements of elephants is a laudable approach and the range extensions on both the western and eastern boundaries of the Park will go a long way in achieving this (for elephants and a host of other species). However, it will remain a closed system and is bound to be colonised in due course, even if the Ghonarezhou National Park is also added as it already has a substantial elephant population.
I seem to sense that the new approach towards the management of the elephant population is essentially an attempt to avoid population control by means of culling. Other than culling, it is highly unlikely that population control will be possible by any alternative means, such as translocations. If population control cannot be exerted I regard the new approach as extremely high risk. This is based on the following:
- It is quite apparent that the Park does not have the research capacity to properly evaluate and prioritise areas that would qualify for ‘event-driven’ intervention.
- It is not clear what ‘intervention’ implies. If it does not entail the reduction of the elephant population where are the elephants of the impacted area supposed to go?
- Justifying the unchecked increase of the elephant population on the basis of an “early signal”, supposedly signifying the reduced increase and leveling off of the population, is scientifically unfounded.
- Any suggestion that the elephant population would eventually level off and continue at a stable level in harmony with other ecosystem components does not take into account elephant population cycles and is therefore equally unfounded on a factual/scientific level.
After nearly 30 years of culling the elephant population has shown no discernable ill-effects and has been kept at a stable level. This, in itself, is not without problems as indicated elsewhere in this submission. However, it was possible to maintain the population within manageable levels and offered the opportunity of adjusting to identified and/or perceived problems.
To let the population go on the grounds of unproven and wishful assumptions (however popular this may be in terms of public sentiment) can very well lead to an irreversible situation that offers very little opportunity to manage the population or effect rehabilitation of disturbed areas if and when the “early signal” assumption may, in fact, prove to be false. This would be akin to signing a contract without an escape clause!
If one has to err, err on the conservative side and retain the opportunity of redeeming mistakes, even if they are – as accepted – made with the best possible intentions.
These notes, following a welcome engagement with Dr Sam Ferreira, are submitted as an official submission to, and for consideration by, the Research and Management sections of the Kruger National Park and copied to Dr David Mabunda, CEO, SANParks, who first informed me of the change in direction in the management of the KNP’s elephant population.
Dr SCJ Joubert
5 October 2010
Comments by Dr Ian Whyte
Comment 1: “It is not possible, without substantial bias, to census elephants”.
The photographs used by Dr Ferreira to illustrate the “ineffectiveness” of the aerial censusing of elephants is entirely inappropriate. These photos were taken from a fixed wing aircraft flying on a predetermined transect from which it would not deviate – even for the purposes of obtaining a more accurate total of the elephants seen. When elephants were seen, as many photos of the group would be fired off in the direction of the elephants as the aircraft passed by. Later examination of all the photos for each group was expected to show up other animals obscured in some of the photos. While looking through a camera’s viewfinder, it is not possible to determine the limits of the group and many are obscured by trees/shrubs at the moment the photo was taken. I know this as I participated on two such censuses in Kafue and the area north of the Okavango “pan-handle”. In my opinion this technique is the most ineffective of all the techniques that I have been exposed to. I would not advocate this technique to anybody. The only way to get an accurate count of elephants in thick bush is through the use of helicopters such as that used in KNP. This was acknowledged to me by Dr Iain Douglas-Hamilton ( a man who has vast experience of aerial elephant censusing from all over Africa) during a visit to Kruger in which he participated in the helicopter census. In my view, a claim that elephants can not be censused is clearly a statement by someone who has no experience of helicopter counts!
Comment 2: “Reproductive ‘spike’ of elephants in response to culling”.
There is absolutely no evidence to suggest that the reproductive “spike” seen in the census of 1995 was the result of the cessation in culling. I believe that this spike was real as I was the observer tasked with counting calves during this census, and I had become very aware of observer bias and was particularly conscientious about trying to exclude calves that could have been more than one year old. The reason for counting these small calves was to try to determine the numerical increment through births to the population since the previous census. However, it is very difficult to distinguish between calves of just less than one year from those that are just older than one year. It is a subjective assessment that is very dependent on the experience of the observers, and is impossible to get this exactly right. But I have no doubt that there were an unusually high number of calves born in the year prior to that census.
Elephant have a normal inter-calving period of ±4 years (3.99 years as calculated for my PhD). It is therefore impossible for an elephant population to maintain a high reproductive rate every year. Usually a “spike” occurs after droughts when reproduction has been suppressed due to nutritional stresses. This has been well documented, particularly for the Amboseli (Kenya) where reproduction virtually ceased during a severe drought (Moss 1988). This was followed by a dramatic “spike” once the drought was broken and the females returned to breeding condition. This may well have been the case in KNP in 1995 as the previous eight years had apparently experienced lowered calf percentages (excepting for 1992). To claim that this spike in 1995 may have been the result of the cessation of culling is flawed as culling only ceased in 1994 and, as the gestation time of elephants is 22 months, it would have been impossible for breeding to have responded in a single year.
TABLE 1: Calf percentages recorded in respective annual aerial censuses
|Year||Recorded Total||Calves||Calf %|
Comment 3: “If left to increase the elephant population would eventually level off and maintain a stable density”.
This statement may well be true but it does not take cognizance of the impoverished condition to which the ecosystem will have been reduced before these mechanisms begin to operate on stabilising the elephant population. Amboseli and Tsavo are prime examples of this. Biodiversity will be severely impacted upon before the elephant population begins to show signs of stabilising. This is not in accordance with SANParks mission of maintaining biodiversity – the two concepts are totally at odds with one another. I personally believe that the population is nowhere near maintaining a stable density. As long as there is adequate food and water, the population is likely to maintain its growth rate of between 5% and 7%.
Comment 4: “There are early signs of the elephant population approaching its asymptote”
I would really like to see any data that suggest that the elephant population approaching its asymptote. Any slowing of population growth inside KNP will almost certainly be the result of emigration into Mozambique. Censuses in KNP and associated adjacent conservation areas must be coordinated and conducted using comparable techniques, to obtain an estimate of the greater Kruger elephant population. Without this, any suggestion that population growth is slowing would be unfounded and spurious (perhaps even mischievous and deliberately misleading?).
MOSS, C.J. 1988. Elephant memories. Thirteen years in the life of an elephant family. Elm Tree Books, London.
Extract from: Whyte, I J. 2007. Results of the 2006 and 2007 censuses of elephant and buffalo in the Kruger National Park, Unpublished report, Scientific Report 06/2007, South SAfrican National Parks
Accuracy and precision of the censuses. In wildlife census terminology, the words “accuracy” and “precision” have fundamentally different meanings (Craig Pers. comm.; Norton-Griffiths 1978; Mbugua 1996). Different censuses of the same population of elephants will deliver different results even if the same technique is used. Should such different censuses yield results that are closely similar, the census technique is considered to be “precise” even though the result may not reflect the “true” population (e.g. the technique may deliver a consistent under-estimate). On the other hand, a technique which delivers a result which is close to the “true” population is considered to be “accurate” though the confidence limits may be wide (sample counts usually deliver such results). The census technique used in KNP does not allow for the statistical estimation of its confidence limits, and the true size of its elephant population is therefore unknown. The accuracy of the technique is therefore also not known, but the high degree of sampling intensity coupled with the precision obtained (see below) suggest that an accurate result is also obtained.
Since 1982, a simple calculation has been used in the respective census reports to give an estimate of the accuracy of each census. This has been done by taking the previous year’s census total and adding the recruitment (the number of calves recorded during the subsequent census) and then subtracting mortality (the number of elephants known to have been removed from the population since that census). This gives the “expected” census total. This equation ignores natural mortality, but this is known to be very low due to the low number of carcasses recorded during censuses (see “carcass ratio” below). The estimate of the precision of respective censuses is:
Ny+1 = Ny + By – Cy
where Ny = number of elephants recorded during the census of year y, By = number calves of < one year old recorded during the census of year y+1, Cy = number culled or translocated out of KNP between the censuses of year y and y+1.
The difference between this expected total and the recorded total should give some indication of the accuracy of the census.
There are three assumptions in this calculation. They are:
- That the previous census total was “accurate”; 2. That natural mortality over the period between the two censuses was minimal; 3. That all calves of less than 1 year old are correctly classified as such.
Whyte & Wood (1992) showed that the criteria use by observers for the estimation of the age of calves under one year old from the helicopter during the census were prone to error. These criteria are very subjective and in most instances an under estimate of the calf percentage is obtained (some calves of nearly one year old are ignored as they were considered to be older than 12 months). That means that more elephants were counted than would have been “expected. Estimates of the accuracy of previous censuses are given in Table 4. These show that since 1982, 17 of the 24 estimates were higher than were expected (the error was on the positive side).
In the year 2000 and again to a lesser extent in 2004, the actual totals were very much lower than were expected, indicating a problem with the result. This was ascribed to the poor census conditions prevailing at the time of these censuses (Whyte 2005). The results of years in between are all much higher which can be ascribed to improved census conditions.
The estimated error for 2006 (-6.2%) and 2007 (+2.2%) respectively suggest that reasonable conditions were obtained as both are close to the mean error of 4.4%. These days however, these totals are influenced by movements across the KNP’s boundary, either to the east into Limpopo National Park (LNP) or to the west into the Associated Private Nature Reserves (APNRs). See also the section on Lowveld population totals.
Table 4: Estimates of the accuracy of respective elephant censuses in the Kruger National Park since 1982.
Culls & captures
Expected Difference % Difference Total (B) total (A) B – A
1982 8 051 – 473 – – – 1983 8 678 763 1356 8 341 337 3.9 1984 8 273 305 1377 7 627 646 7.8 1985 6 887 296 369 7 192 -305 -4.4 1986 7 617 495 498 7 013 604 7.9 1987 6 898 157 304 7 276 -378 -5.5 1988 7 344 231 356 6 825 519 7.1 1989 7 468 220 366 7 208 260 3.5 1990 7 278 145 364 7 247 31 0.4 1991 7 470 141 358 7 055 415 5.6 1992 7 632 498 479 7 610 22 0.3 1993 7 834 278 390 7 431 403 5.1 1994 7 806 217 356 7 661 145 1.9 1995 8 064 815 127 8 265 -201 -2.5 1996 8 320 219 76 8 156 164 2.0 1997 8 371 433 51 8 677 -306 -3.7 1998 8 869 431 31 8 751 118 1.3 1999 9 152 220 12 9 058 94 1.0 2000 8 356 250 27 9 390 -1034 -12.4 2001 9 276 326 40 8 655 621 6.7 2002 10 459 379 40 9 615 844 8.1 2003 11 672 310 51 10 729 943 8.1 2004 11 454 420 – 12 092 -587 -5.1 2005 12 467 608 20 12 062 405 3.2 2006 12 427 725 2 13 192 -745 -6.0 2007 13 050 338 – 12 765 287 2.2
Ave. error: 4.62%
Natural ruses rule out culling for elephants (South Africa)
GLYNIS O’HARA, Conservation Action Trust
22 NOVEMBER, 2014
There will be no further culling of elephants in Kruger National park for population control.
So says Dr Sam Ferreira, SANParks’ large mammal ecologist. That’s because the new, “natural”, methods of managing them have severely curtailed the population growth rate, bringing it down to just 2%, from a high of 6,5% when culling was stopped in 1994.
Managing the effects of elephants is not about controlling populations. It is about letting natural processes influence where elephants spend time and what they do when they are in particular places.
Culling did not work for managing elephant impacts, admits the Kruger’s Elephant Management Plan, and the new method of imitating natural processes appears to be doing a much better job. Culling could, however, be used, in other scenarios, such as shooting a problem elephant, he said.
The current elephant population is estimated at around 16 900, said Dr Ferreira, based on the last count in 2012. It was 8 000 in 1994. However, without the new, more natural methods of control, the population would have been over 25 000 by now, if the 6,5% increase rate had continued at the time when culling stopped.
The new approach to manage the impacts that elephants have on various conservation values is a more ”natural” one, largely through limiting access to waterholes. Over two thirds of them were closed after 2003, starting in the drier, northern areas. As elephants moved away from newly closed boreholes, the landscape and vegetation got respite from elephant use.
Managing impact does not mean managing the numbers of a population – it’s now all about how elephants use the landscape and managing that. “Elephants need shade, water and food and prefer avoiding people,” said Dr Ferreira. “In the Kruger they used to have water within 5km of wherever they were and they had no reason to move around extensively.
“But now we’re restoring natural patterns. We’ve closed boreholes and we’re removing some dams, although that’s a much bigger operation. We’ve also dropped fences between ourselves and Mozambique in the north and private reserves in the west, allowing more spatial range.”
As expected, a typical natural process unfolded — with less easily available water, more calves and elderly elephants died and the birth rate went down. (The Kruger’s last major drought was in 1992/3, so the impact of fewer waterholes during drought is still to be seen.)
An elephant cow, pregnant for 22 months, could in the best circumstances have a calf every three years, said Dr Ferreira. But now, with the water restrictions, elephants are giving birth every 4.2 to 4.5 years. “It’s a classic population response.” Cows have to walk further to get to water and food and it takes its toll on body condition, hence reducing the rate of conception. Calves suckle up to three years when they start to get their tusks. After that, they have to walk to water and food, like the rest of the herd.
None of this means Kruger is littered with the bodies of dead calves, Dr Ferrreira hastens to explain. “One calf dying irregularly can set back a herd by four years,” he says.
The responses in the Kruger have been different in different areas. For example, in the north, survival rates have declined, while in the south (where there’s more natural water), the birth rate has declined. It’s not yet clear why that’s happening. “But basically, elephants are starting to look after themselves.” Natural regulation is taking place.
For the scientists, observing the impact of borehole closure and the changes in elephant reproduction rates takes time. “An elephant generation is 12 to 15 years and we have to monitor behaviour and impacts over the years.”
Now that more boreholes are closed, for example, elephants have moved to the rivers, accentuating impacts on vegetation there, and such “lag effects” have to be studied and managed. “We’ve identified 32 places where lag effects are happening, and we’re calling them ‘areas of concern’. One of the ways we have of addressing the issue is to mimic human presence as a deterrent.”
This could be done through various disturbance techniques, like noise (firing guns into the air for example), or small fires, using bee hives, or putting up a fence with chilli-pepper on it. The last has been experimented with at the Kruger’s nursery, where they used a cloth soaked in chilli pepper sauce. “Elephants just avoid it. But it only serves as temporary deterrent, they’re very clever and they’d eventually get used to it. As for the bees, the thing is that they have to survive long, dry seasons too.” There have been experiments with beehive sounds, but again, the elephants would work it out after a while. “It would need a reinforcement technique,” says Dr Ferreira.
Tourists have to be considered too. The main north-south road “historically was a military road and there weren’t that many places to see animals, so they put in boreholes to bring the animals to the tourists. Now we want to take the tourists to the natural water areas, through loops off the main road.” But creating new infrastructure takes time, the Kruger Park Elephant Management Plan acknowledges, adding that some artificial water may have to be maintained to manage visitors’ expectations.
Tourists have also always enjoyed the historic big trees at the rivers and preserving them is a concern for the park. One way to keep elephants away is by packing large, sharp rocks around them.
The data on vegetation effects is not conclusive in the Elephant Plan, published in 2012. “Limiting elephants did not prevent a decline in the structural diversity of the woody vegetation of Kruger,” it says. In fact, “vegetation diversity increased with high elephant density in certain regions of Kruger”. So it’s an area that needs a lot more study and understanding.
One of the complexities is that the highest rates of damage are not necessarily where the highest densities of elephants are. The impact is not necessarily related to numbers, and this, it turns out, may be all about the boys. Elephant bulls take a very long time to mature, producing viable sperm at about 15, going into intensive musth cycles at about 30 and really becoming competitive at 40- to 45 years of age, said Dr Ferreira. “So teenage boys may get very frustrated and thrash trees. And therefore the kind of elephants we have in a particular spot is important.”
As far as human-elephant conflict goes, in South Africa, there’s been a relatively low number of incidents with villagers on the edge of the park, says Dr Ferreira.
“I have yet to see the fence that will keep an elephant in all the time. We’ve collared about 150 elephants and only one of them has never left the park.” Mostly they moved into private reserves and into Mozambique.
“Most elephants will move out of the park at night when the marula tree starts fruiting, eat the fruit and come back, avoiding humans. But the elephants flatten the fence and buffalo can then get out and they can carry disease and contaminate domestic stock. So what’s the solution? One idea is to build a lower fence that elephants can step over but that keep the buffalo inside the park.”
The main problems for villagers, he said, were actually drought, disease, and wild animals like rodents, baboons and monkeys. The Management Plan also mentions predators. Elephant conflict is actually rare. Legislation does however, allow a provincial authority to shoot a “damage causing animal” once it’s outside the Park.
In effect, this is a giant experiment, to see how all the Kruger’s animals, including the elephants, adapt to the changes. So far, so good. And if we never need to repeat awful scenes of herds of elephants being gunned down from helicopters, the scientists deserve a medal.
Elephant poaching in Kruger
Just two elephants had been poached in the north of the park this year, said Major- General John Jooste, Commanding Officer of Special Projects at Kruger.
Elephant poaching is not a crisis in South Africa as yet, unlike in East Africa (where 12 000 are estimated to die annually), said Dr Ferreira. “We’re probably also in a better position to deal with it, because we have anti-rhino poaching forces in place already,” said Dr Ferreira.
There are some logistical problems for would-be poachers, Dr Ferreira explained. After shooting an elephant, it takes some time to cut out a tusk. “Then you have to hack off the head to get at the other tusk. So the poachers spend a much longer time at the locality than with rhinos.” And the longer the poachers take, the more likely they’ll be caught, given that there are anti-poaching units patrolling the park.
The Kruger’s Elephant Management Plan
The focus for Kruger Park is on natural population and spatial use management and a tolerance of nature in constant flux.
Other parks with elephants are including contraception in their plans, but not Kruger at this stage.
The plan focuses on maintaining, or restoring, ecosystem integrity; providing benefits to people; and taking cognisance of aesthetic and wilderness qualities.
Five key objectives, often overlapping, cover areas such as managing elephant ecological impact, damage-causing elephants, anti-poaching (“low” incidence at the time of the report), aligning plans and policies with adjoining parks and stakeholders, including Transfrontier Conservation Areas, and monitoring and research.
“Adaptive elephant management” includes a complex table of options for the different regions, with “lethal shooting” as an option for human- elephant conflict as well as for vegetation loss and loss of large trees.
Culling is accepted in the government’s Elephant Norms and Standards policy of 2008 as an option of “last resort” only that has to conform to “strict conditions”. A “culling plan” has to be prepared with an ecologist and approved by “the relevant issuing authority”.
The plan notes that six people were killed by elephants between 2000 and 2005 (5 villagers and one ranger), although it does not say where this was. In the same period, 75 elephants associated with fence breakage and damage to property were killed by the Limpopo Department of Environmental Affairs, while the Mpumalanga Department “killed an unknown number” south of Olifants in recent years, it says.
SAPA reporter, May 2013
ELEPHANTS JOHANNESBURG May 3 Sapa
KRUGER ELEPHANTS ‘MANAGEABLE’
The Kruger National Park’s (KNP) elephant population is manageable and has not reached crisis levels, SA National Parks (SANParks) said on Friday.
A Sapa correspondent reported SANParks had rejected claims by the park’s former director Dr Salomon Joubert, who said the elephant population in the area was a “huge problem”.
KNP large mammal ecologist Sam Ferreira said the population was stabilising.
“The elephant population growth has decreased to 3.5 percent [a year].
“The bottom line is that the elephant population at KNP is stabilising, but differently in different landscapes.”
Ferreira said that in 1994, when the park stopped elephant culling, there were about 8000 elephants in the park, and the population was growing at 6.5 percent per annum.
“Predicting that would show that KNP should have 24,500 elephants in 2012,” said Ferreira.
Ferreira said the 2012 elephant census counted 16,700 elephants in the park.
Joubert reportedly said there was an over-abundance of elephants in the park.
“The animals have knocked the daylights out of important ecosystems in certain parts of the park, and it is going to be extremely difficult or impossible to reduce the population to manageable levels,” Joubert said.
He believed that thousands of elephants needed to be culled to control the population.
Ferreira said SANParks sought to manage the effect of elephants and not the elephants per se.
“We have taken the lead and are focusing on managing direct mechanisms of ecological conflict effects. Elephant culling is part of our management plan, as well as the closure of artificial water-holes and increasing the size of the park to allow easy movement by elephants.”
Though the elephant population size was increasing, it was doing so at a slower rate due to declining birth rates, he said.
“This accounts for the lower than predicted number of elephants. SANParks considers this as strong evidence for natural control of elephants.”
Ferreira admitted that the elephant poaching crisis in neighbouring Mozambique could spill over into the KNP.
In a 2011 aerial survey of Mozambique’s Niassa Reserve, 2667 elephant carcasses were counted.
According to the Convention on International Trade in Endangered Species, the illicit trade in ivory is estimated to have doubled since 2007 and more than tripled over the past 15 years.