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    The tsetse fly and the disease that it spreads - Nagana, have played a major role in the history of the Mkhuze Game Reserve. Nagana is a wasting disease in domestic stock caused by a blood parasite spread by the fly. There are 19 species of the fly, 3 of which were to be found in Zululand. One species in particular, Glossina pallidipes almost resulted in the abolition of not only the Mkhuze Game Reserve, but of the other major game reserves in Zululand, such as Umfolozi and Hluhluwe as well. Unwittingly though, the fly was to become an unlikely ally in the battle to retain the reserve, by delaying its deproclamation.

    To understand the problems caused by Nagana, it is necessary to take a brief look at the life cycle of the fly and the history of the disease in Zululand. Tsetse flies are to be found in "fly belts", the limits of which are controlled by various factors such as vegetation, shade, moisture and the presence of game. The flies are solely dependent on blood for their food and become infected by engorging on game, which are immune to Nagana. The mouthparts of the tsetse fly contain a hollow proboscis that is used to pierce the skin and draw up blood, as with a syringe. The blood, along with trypanosome parasites from game animals, passes into the insect's stomach and, in time, some of the parasites lodge in on the fly's proboscis. When the fly takes it next meal, and if this is on a domestic animal, the parasites are transmitted to the new host. The flies therefore become the carriers of the trypanosomes parasites responsible for the Nagana disease in domestic animals. A single infected fly may infect several animals through its bites in the course of obtaining a single blood meal.

    This highly specialised insect has a unique life cycle. The fly larvae are deposited in sheltered spots on loose sandy soil, in bush thickets or under the low canopy of a single plant. The larvae burrow their way into the loose soil where they pupate within 1 to 3 hours. The pupal period varies from 15 to 70 days although they have been known to survive in this state for as long as 90 days. Since 1890 the tsetse fly Glossina pallidipes had been the cause of great concern in South Africa, particularly in the Transvaal Lowveld and Zululand. This hardy insect could exist in thinly scattered communities, feeding on small game such as warthog, bushpig and bushbuck and it was considered to be the most difficult of all the species of tsetse flies to eradicate.

    Following the annexation of Zululand to Britain, it was brought to the attention of Sir Charles Saunders, later Chief Magistrate and Civil Commissioner for Zululand, that the local population were dependant on game for food and that very little game existed, except in the uninhabited localities. As a consequence of this, strict laws for the preservation of game were passed. This had a counter-productive effect. Unknown to the colonists, the subsequent increase in the numbers of large game animals in the Colony caused a corresponding increase in the occurrence of tsetse flies, which spread Nagana amongst domestic cattle. Drastic action in this matter became an urgent necessity.

    When Surgeon-Major Sir David Bruce, arrived in the primitive settlement of Ubombo, near the Mkhuze Game Reserve, in 1894, he found conditions a far cry from his native Scotland. He was on an important mission though. Very little was known about the tsetse fly until the 1890s and he had been invited by the Governor of Natal and Zululand, Sir Hely-Hutchinson to investigate the causes of Nagana, which was resulting in large-scale mortality in cattle. Since the expansion of European settlement into Zululand in the 1890s, following the Anglo Zulu War of 1879, there had been speculation amongst the Colonists that the disease known amongst the local population as "Unagane", was caused by cattle associating with the tsetse fly. The fly was prevalent in areas inhabited by big game and, to many residents in Zululand, there was a definite relationship between game, the tsetse fly, Nagana and Rinderpest. Bruce was employed to investigate the problem.

    Long before Bruce began his investigations into the disease, the Zulus had their own theories as to why their cattle were dying. They believed that their cattle caught "Unagane" by grazing and ingesting the saliva left by big game feeding on plants in areas where such animals were to be found. When Bruce arrived at Ubombo, the mechanics of the disease were not clearly understood. From his research post at Ubombo, Bruce reported that the whole of the Ubombo and Ingwavuma Districts were tsetse "fly belt" areas. It was impossible to keep domestic stock here because of the disease and, towards the end of 1894, by analysing the blood of diseased animals, he had identified the tsetse fly as the carrier of Nagana. It was David Bruce who discovered that the adult tsetse fly acted as a carrier of the living parasite that was to be found in the blood of wild animals. His early findings were published in a report entitled Tsetse Fly Disease or Nagana in Zululand.

    Following the Rinderpest epidemic of 1896, strict measures for the preservation of game were introduced and enforced. No permits were issued for the destruction of "royal game", a category that excluded kudu and buffalo, two of the major carriers of the disease. The Rinderpest epidemic had led to a practical absence of Nagana from 1897 to 1905 but, with the stricter game laws in force at the time, Nagana started to reappear. Numerous complaints were received from transport riders and the local population concerning deaths amongst their cattle as the disease spread from one district to another, beyond the confines of the game reserves.

     The opening up of approximately a third of Zululand for white settlement in 1906 aggravated the position. Many of the new settlements were close to the game reserves that were in existence at the time and they were thus exposed to Nagana, a factor that was to have far-reaching consequences later. The problems associated with Nagana continued to plague the inhabitants of Zululand for more than a decade, before the central government appointed R.H. Harris in 1921 to carry out further investigations into the tsetse fly problem. With the allotment of farms in the Mkhuze area in the late twenties, the Nagana problem had became more serious and the measures of bush clearing and burning, which had to date been employed against the tsetse fly, were intensified. Additional staff was appointed in 1927 to work on the Nagana problem and Harris, who had retired in 1926, was re-employed in 1929 to renew the battle against the tsetse fly. From 1929 through to 1931, 35 000 head of game was destroyed in Zululand, including 2000 zebra and many inyala from Mkhuze. Dr George Campbell, Chairman of the Natal Branch of the Wildlife Society, paid a visit to Zululand at the time and wrote a scathing indictment for the press of the wholesale slaughter that was carrying on. He complained, in particular, of the "complete lack of scientific control of the whole campaign. Take for example, the destruction of game in Mkhuze, and the terrible slaughter of inyala, our rarest and most beautiful species on the Ubombo Flats". It was around this time too that the regional control of the Zululand game reserves underwent significant changes, with the retirement of Vaughan Kirby and the appointment of Symons and Potter.

    Harris's investigations had led him to a realisation that the tsetse fly hunted by sight rather than smell and this, in turn, led to the invention of the Harris Fly Trap in the late twenties. In Harris's early experiments with his tsetse fly trap he used an inverted packing case with a hessian skirt around the base and within a few hours of placing it in the bush, the box had trapped 82 tsetse flies. The design of the trap was refined and later consisted of a large hessian-covered wooden structure, with galvanised iron sides, surmounted by a wooden box. It was designed to resemble an animal in size and shape. It used no bait and attracted flies purely through their visual sense. A tsetse fly, seeing the trap, would take it for an animal and settle on the "underbelly of the beast" entering the trap through an opening at the bottom. It then made its way to the wooden box at the top of the trap, from which there was no escape. The traps, which cost \A37 each, were considered to be a good mechanical device for recording the presence of the fly and by 1938, 25 000 of them were in use in Zululand.

    The Veterinary Department had planned an extensive anti-Nagana campaign in Mkhuze and on 24 October 1938, Captain Potter wrote to the Provincial Secretary advising him that activities of the Nagana research team were about to be begin. On 19 May 1939, the Director of Veterinary Services, Dr P.J. du Toit, wrote to the Provincial Secretary as well, confirming that it had been agreed some years ago that Mkhuze should be deproclaimed as a game reserve. This was to allow the Veterinary Department free rein in their measures to combat Nagana. Action in the matter had however been delayed because of fly-trapping operations taking place elsewhere in Zululand. He informed the Provincial Secretary that Onderstepoort was now anxious to start its campaign in Mkhuze and that the first consignment of traps would be sent to the reserve during the next few weeks. At the same time he sent in his recommendation that the deproclamation of the reserve should not be gazetted immediately.

    Dr du Toit followed up his letter with a personal visit to Zululand in September 1939. After this trip he changed his mind about agreeing to take over control of Captain Potter's guards and having them in the reserve. He met with Potter during his visit. In the report written on his return from this trip he stated "I made it quite clear at the outset that to make a success of our campaign in this reserve we should have to take complete control over the whole area, including the game in the area. I explained that it would be better not to have any of Captain Potter's guards in the Mkhuze reserve, when once we started our operations. We should prefer to appoint our own guards, should that be found necessary. I also made it clear that, for the present, we did not wish to have the Mkhuze Reserve deproclaimed. It would be better for the public still to regard this as a reserve in which no shooting was allowed; otherwise deproclamation would simply have the effect of attracting large numbers of biltong hunters who would come to Mkhuze for a cheap shoot".

    It is again ironic to note at this point in the history of the reserve, that the existence of the fly in the reserve once more saved it from deproclamation! The very argument that had so persistently been presented for the past 25 years in efforts to get the reserve deproclaimed, namely the presence of the tsetse fly, was now to become an ally in the retention of the game reserve. In the light of what subsequently happened it is sad to note how inaccurate an earlier statement of Dr du Toit's, that it would not be necessary to destroy much game in the reserve, was to become. He did add at the time "it would be quite impossible to guarantee the safety of all Royal Game as it might be necessary to shoot some of these animals in the course of our work". He also added that the "the best way of overcoming the difficulty would be to give special rights to Mr Harris and his staff to shoot Royal game and any other game in the Mkhuze area. Mr Charter (Secretary, Zululand Game Reserves and Parks Board) will take the necessary steps to obtain this right for our staff".

    On 1 October 1939 it was agreed that control of Mkhuze would formally pass to the Veterinary Department and Captain Shenton was appointed to the reserve in November as a temporary ranger. On 15 February 1940 a letter from the Provincial Secretary was sent to Shenton, appointing him under the game ordinance to control Mkhuze. He had 8 game guards under him, whose duties were to be the prevention of poaching within the confines of the reserve. His staff was supplied with tunics and identification armbands to indicate that they had the necessary authority to act in this capacity. The Zululand Game Reserves and Parks Board was again given the assurance that there was no intention at the time of destroying large numbers of game animals and, in particular, of interfering with the black rhinos in the reserve. Practical control of Mkhuze passed from the Zululand Game Reserves and Parks Board to the Veterinary Division in 1941. 

    The Veterinary Division's initial campaign was based on the belief that Nagana could be eradicated through the extensive use of the Harris Fly Trap and by clearing areas of bush to create effective barriers, thereby destroying likely breeding places of the fly. By clearing the bush the flytraps would also become more visible to the flies. Twenty-one thousand traps were already in use at this time in the Umfolozi and Hluhluwe reserves and arrangements had been made early in 1940 to send additional traps to Mkhuze. The traps did not have the desired effect though of eradicating Nagana from the area.

    A second major campaign against the disease was undertaken from March 1943 to February 1950. The objective of this campaign involved the wholesale destruction of game. The thinking behind this strategy was that, if sufficient animals were destroyed, the fly would be deprived of its host and Nagana would disappear. The rationale behind this theory ignored the fact that it would be virtually impossible to wipe out all the species of wild animals that could act as hosts to the fly.

    This was a controversial subject, even within the Division of Veterinary Services and Dr du Toit himself was not in favour of it. By the time the campaign started 24 guards had been employed to do the shooting and patrol the boundaries of the reserve.

    Before the shooting started, a report was submitted to the Onderstepoort Veterinary Laboratory on 30 October 1942, which included estimates of the numbers of impala in the reserve to be 2500, inyala 1500 and blue wildebeeste 1600. The inaccuracy of these figures was to become apparent when the final tally of animals destroyed was made. After completion of the campaign, a report submitted to the Chief Conservator, Zululand, Captain H.B. Potter by W. Foster of the Nagana Research Station at Mtubatuba revealed the enormity of the slaughter that had taken place. Accurate records which were kept at the time revealed that from March 1943 to February 1950, 38 552 animals were destroyed in the reserve, adjoining Crown Lands and unoccupied farms close to Mkhuze. This figure included 6726 blue wildebeeste, 4385 inyala, 17060 impala and 7436 grey duiker. In the relentless destruction that had taken place, rare animals such as Suni antelope were also hunted and 80 of these were shot, as were 434 red bush duiker and 2 black rhino. This figure is far in excess of the figure estimated to be the total game population of the reserve in October 1942.       

    The method employed in the campaign was to systematically destroy the game from the periphery of the reserve, moving systematically towards the centre. This was to avoid scattering the game and spreading the flies over a wider area. It was organised to include all species of game. The operation was carefully controlled and all animals destroyed were recorded. The tails of the shot animals had to be submitted as well as blood, spleen and liver smears. Every round of ammunition used had to be accounted for. By the time this futile exercise had run its course new initiatives to combat the disease had been developed which, after introduction, would finally spell the death knell of Nagana in Zululand.

    In 1945 it was decided that, in addition to the shooting campaign, the use of insecticides such as DDT to control the fly should be investigated. Laboratory tests had proved that DDT was effective against tsetse and other species of flies and it was decided to experiment with the trial spraying of a designated area from the air. Mkhuze was chosen for the first experimental spraying as the terrain was flat and therefore less dangerous for the pilots, who had to fly low over the control area in tight formation. The area to be sprayed was demarcated by a series of flags and the initial experiment carried out in Mkhuze was to establish the degree of susceptibility of the fly to DDT. Other factors which had to be determined were the most suitable aircraft to use, the solution, method and speed of delivery, optimal flying height, best time of the day for spraying. The effect of wind on the distribution of the insecticide also had to be determined.

    A landing strip was cleared for aircraft and the first experimental spraying in Mkhuze, to establish the most suitable aircraft for the task took place on 20 October 1945. The Division of Chemical Services had developed special smoke generators, which could be fitted to the aircraft. These worked on the principle of dissolving DDT in furnace oil and spraying the mixture through the venturis of the aircraft. The DDT was used in this oily solution because it was found that it achieved a better distribution on bark and leaves. Experiments also established that Avro Anson aircraft, which could be made available by the Department of Defence, were the most suitable for the task. The aircraft were fitted with special tanks, each holding 400 litres of the DDT mixture. Before the pilot took off, the area to be sprayed was demarcated by smoke generators, in addition to the flags.

    This trial spraying at Mkhuze was the first attempt made to eradicate the tsetse fly by means of DDT sprayed from the air. The initial results were encouraging and eventually led to the Veterinary Department's successful efforts to control the disease. Suitable aircraft were put at the disposal of the Veterinary Department and the first three fully organised aerial sprayings of the reserve took place from 26 November 1945 to 15 January 1946.

    An Anson sprays its DDT mixture onto the Bushveld

    These early sprayings were not without their problems. On the first day planned for spraying, the operation could not be undertaken because of the velocity of the wind. When the planes could take off, the pilots experienced difficulties with the clogging of the venturis used to deliver the spray and they could not produce the required swarf. It was also soon discovered that it was impractical for the pilots to try and cover the whole reserve by navigating with their compasses, as had initially been planned. A system of mapping out the areas to be sprayed, using flags and smoke generators had to be developed. This method was later used with great success. It was also soon discovered that a method had to be evolved to use crosswinds to ensure that the DDT spray was delivered in waves over an area. These problems were all eventually sorted out to the pilots' satisfaction. On 10 December 1945, Dr Gilles De Kock of the Department of Veterinary Services could report to Mr W. M. Power that "as regards the whole mechanical procedure, we can now say that we have mastered the situation and the ground organisation has also been perfected". 

    "How far we will be able to destroy the active fly or the lurking fly or the resting fly by this procedure is at present not known or whether we will have the desired effect with the residual effect of the spray. Furthermore we have to contend with new flies hatching from the pupae deposited some time previously. Our intensive trapping in the high fly density area, which is being recorded daily, will indicate to what extent a drop in the fly-catches has taken place. It will certainly take us some time before we can form a definite opinion as regards the efficacy of the spray from aircraft".

    He went on to say "I am of the opinion that, with the organisation as it exists at present and providing weather conditions are satisfactory, the spraying of approximately 25 square miles of the fly density area in Mkhuze Game Reserve should not take longer than 3 to 4 days. That will give you time to go to the reserve to see what is being done under existing conditions ".

    After the first three sprayings, further spraying had to be delayed until the winter of 1946. This was due to heavy rain in the reserve and the prolific growth of grass and bush. Two more sprayings were done in August and September 1946. The success of these early sprayings could be gauged from the results recorded in the traps. Using 230 Harris traps the number of flies caught in them dropped from 22007 in November 1945 to 3705 in March 1946. By September 1946, 291 Harris traps caught only 405 flies.

    One of the Avro Anson aircraft came to grief in the reserve near the present airstrip and its remains are still to be seen there today. The area was subsequently named "Bhanoyini" - the place of the aeroplane, by the African staff employed in the reserve at the time.

    Leonard Charles "Singie" Denyer arrived in Mkhuze from East Griqualand in August 1941, having been employed shortly before by the Department of Veterinary Services as an Assistant Stock Inspector. He was to take control of the anti-Nagana campaign in the reserve. Known amongst the Africans as "Majuta" a name given to him for his shrewd bargaining prowess whilst managing a trading store in Mtubatuba. The circumstances of Singie's arrival and early days in the reserve will be related elsewhere. Having been employed by both the Veterinary Department and subsequently by the Natal Parks Board, Singie was a mine of information regarding the anti-Nagana activities in the reserve and the later return of Mkhuze to the Board's control.  One of his first tasks after he and his wife Dawn arrived in the reserve was to move into the very simple three-roomed reed cottage, with a lean-to. After that he was to recruit a labour force of 50 men for bush clearing, road making and for the building of huts for the staff employed in leading the "bait cattle", which were used to monitor the presence of tsetse flies. These camps, built entirely from local material in the form of bush timber, mud and thatch, were later to be used by the shooting gangs employed in the game eradication campaign.  Roads in the reserve were non-existent at the time and only a few rough tracks connected the various shooting camps. When it rained these became impassable and the camps were isolated until the roads dried out again.

    Tsetse flies were, of course not the only insects killed by the aerial spraying and a team led by Dr Ripley from the Division of Entomology at Cedara College near Pietermaritzburg monitored the situation closely to establish the effects of the DDT on other insects, including useful ones. Lamps were put outside at night over sheets to establish the extent of the remaining insect population and rotten meat was left outside to see what insects could be attracted to it. There were other and more pleasant ways of determining the effects of the spraying on the insect life. One procedure was to identify specific flowering plants in the reserve and count the number of bees on a plant at a particular time of day. These figures would then be compared with the number of bees recorded at the same time of day, after an aerial spraying had taken place. Singie told me that after each aerial spraying, a fine mesh net was placed in the water across the Mkhuze River, when there was sufficient flow to do this, and catch any insects that had died from the spray and were floating, down the river. The mortality in insectivorous birds, dying of residual DDT poisoning after feeding on insects killed by the spray must have been horrendous and may be left to the imagination. In one report from the Nagana Research Section submitted in September 1947 it was stated that "material sprayed on 5 October 1946 still showed lethal residual effect to exposed flies on 22 October 1946".  

    By April 1949 Dr E.B. Kluge, Officer in Charge of the Nagana Research Station could report that " In the Mkhuze Game Reserve the fly position is very satisfactory. During July 1948 only 2 flies were recorded and in August 1948, only 1". In August, Dr Gillies de Kock of Onderstepoort could report that "in the last three weeks not a single fly was caught in the Mkhuze area. No further flies were recorded until March 1949, when 1 G. austeni was caught at Masheza". In January 1949, Singie Denyer was appointed an officer within the meaning of the ordinance to ensure that the provisions of the game ordinance were carried out.

    The remarkable success achieved at Mkhuze in eliminating the tsetse fly from Zululand resulted in a meeting being held in Pietermaritzburg on 21 October 1952 to discuss the future of the Zululand game reserves. On 17 January 1953 the Secretary for Agriculture wrote to the Provincial Secretary to inform him that his Department had decided to relinquish control of the Mkhuze Game Reserve within three months. In 1953 the reserve was accordingly handed back to the Natal Parks, Game and Fish Preservation Board, but an agreement was reached with Onderstepoort: bait cattle were to be kept in the reserve to establish whether any tsetse flies would make their reappearance. Cattle were, in fact, kept there for a number of years after this date.

    At a subsequent meeting, held on 9 February 1954, the Natal Parks, Game and Fish Preservation Board met with representatives of the Department of Veterinary Services to discuss the future of the reserve. It was agreed at that meeting that Singie Denyer would be offered a post with the Board. It was further agreed that he would also be permitted to control the Veterinary Department's bait cattle, which would have to be left in the reserve to monitor the fly situation. It would be necessary for him to retain his official vehicle to cart water for the cattle. So it was that Singie Denyer joined the service of the Natal Parks, Game and Fish Preservation Board on 1 September 1954. As late as 1960 there was still evidence of the Nagana operations to be found in the reserve. Shortly after my arrival at Mkhuze I was intrigued by platforms of sticks that I had noticed in some of the trees lining the older roads in the reserve. These platforms, I was told, had been put up to store game carcasses that had been shot in the game eradication campaign and which were awaiting collection. Behind the old office next to Singie's house, I also remember seeing the rotting wooden remains of numerous Harris flytraps and their galvanised iron sides, which were haphazardly piled up. Some of the galvanised iron from these old traps was used in a Heath-Robinson device for the collection of rainwater at the ranger's quarters at Sordwana Bay, which at that time fell under the control of the staff at Mkhuze. The rainwater supply was collected from the roof of the ranger's squaredavel and led through a pipe into a funnel made from the sides of Harris fly traps. This funnel led into a hole which had been made in one of the fuel tanks retrieved from the Avro Anson aircraft that had crashed in Mkhuze during the Nagana campaign. The tank in turn was mounted on a rough wooden platform. An old Nagana camp at Sycamore Park, once a popular picnic spot next to the Mkhuze River, now unfortunately inaccessible, was demolished by Ranger John Dixon as late as 1962.

    Perhaps the most interesting relics of the Nagana campaign still in existence in the reserve are the remains of three .303 rifle cartridge cases, from ammunition used in the shooting campaign. These cartridge cases were hammered into a Ziziphus mucronata tree by staff engaged in the destruction of game, who had their camp on the crest of the Ndunagazi ridge, in the western section of the reserve, about 5km from the Mtshopi entrance gate.

    According to Singie, these cartridge cases were from some of the first shots fired in the Nagana shooting campaign. More than fifty years later, the tree, now aged and weathered by the elements, still survives. The three weathered rings of the brass rims of the cartridge cases are still faintly visible in the trunk of the tree - a small memorial to the thousands of animals that perished in the Nagana campaign. They remain as a mute reminder of the senseless slaughter of the time and responsibility, which we all carry to ensure that we act with caution and circumspection in matters that affect our natural order.

    The"cartridge tree" on Ndunagazi Hill


    With the successful conclusion of the Nagana campaign, one of the major battles for the retention of Mkhuze as a game reserve had been won, but the fight to preserve the reserve was far from over. The effectiveness of the aerial spraying of the area and the success it achieved in eliminating Nagana from Zululand, invalidated for all time one of the of the major arguments that had been put forward in favour of deproclaiming Mkhuze. It was later recorded that "the initial results obtained from the early experiments in the Mkhuze Game Reserve were of the greatest significance in the planning of the subsequent campaigns to eliminate Nagana in southern Africa". Despite the success achieved in destroying the tsetse fly and eliminating Nagana, new and persistent demands for the deproclamation of the reserve would continue to be made, under one pretext or another, right through to the early seventies.