Ticks ( Acari : Ixodidae ) collected from animals in three western , semi-arid nature reserves in South Africa

GOLEZARDY, H. & HORAK, I.G. 2007. Ticks (Acari: Ixodidae) collected from animals in three western, semi-arid nature reserves in South Africa. Onderstepoort Journal of Veterinary Research, 74:81–85 The objective of this study was to make an inventory of the ixodid tick species infesting wild animals in three western, semi-arid nature reserves in South Africa. To this end 22 animals in the Kgalagadi Transfrontier Park, 10 in the West Coast National Park and 16 in the Karoo National Park were examined. Fourteen tick species were recovered, of which Hyalomma truncatum, Rhipicephalus exoph thalmos and Rhipicephalus glabroscutatum were each present in two reserves and the remainder only in one. The distributions of two of the 14 tick species recovered, namely Rhipicephalus capensis and Rhipicephalus neumanni, are virtually confined to the western semi-arid regions of southern Africa. Hyalomma truncatum, R. capensis and R. glabroscutatum were the most numerous of the ticks recovered, and eland, Taurotragus oryx, were the most heavily infested with the former two species and gemsbok, Oryx gazella, and mountain reedbuck, Redunca fulvorufula, with R. glabroscutatum.

In addition to the Kruger National Park, which is approximately 2 million ha in size, there are numerous smaller national and provincial nature reserves in South Africa.Besides the mammals, birds, reptiles, fish, arthropods and vegetation that are protected within these reserves the parasites of the various biota are coincidentally conserved with their hosts.The larger reserves are not only important from the conservation aspect, but also because of the opportunity they afford for studies in an environment in which there has been minimal human disturbance or pesticide usage.
In recent times, particular host species and nature reserves have been targeted for the collection of para sites.A number of these studies have been conducted in the Cape Province (now subdivided into the Western Cape Province, the Eastern Cape Province, and the Northern Cape Province).During these surveys animals in the Mountain Zebra National Park, the Bontebok National Park and the Addo Ele-phant National Park were examined (Horak, Sheppey, Knight & Beuthin 1986;Horak, Fourie, Novellie & Williams 1991a;Horak, Boomker, Spickett & De Vos 1992;Knapp, Krecek, Horak & Penzhorn 1997), as well as animals in the Andries Vosloo Kudu Reserve (Knight & Rechav 1978;Horak, Spickett, Braack & Williams 1991b;Horak & Fourie 1991;Horak et al. 1992), and the Thomas Baines Nature Reserve (Horak, Potgieter, Walker, De Vos & Boomker 1983;Petney, Horak, Howell & Meyer 2004).
The present paper provides an inventory of the ixodid ticks collected from wildlife in three semi-arid nature reserves in the erstwhile Cape Province, two in the region now known as the Western Cape Province and one in the now named Northern Cape Province.The helminths recovered from antelopes in two of these reserves have been recorded in a separate publication (Boomker, Horak, Watermeyer & Booyse 2000).
The Kgalagadi Transfrontier Park, that now incorporates the former Kalahari Gemsbok National Park (24°45'-26°28' S, 20°00'-20°50' E), which lay within the borders of South Africa, is located in a semiarid region in the northern part of Northern Cape Prov ince and extends into the neighbouring country of Botswana.The vegetation consists of a mosaic of lightly wooded grassland on the dune crests, pure grassland in shallow depressions between the dunes, and Rhigozum trichotomum shrubby grassland in deeper hollows where the underlying calcrete is close to the surface (White 1983;Acocks 1988).During October 1984 22 animals were examined for ticks in the central region of the former Kalahari Gemsbok National Park.
The West Coast National Park (33°06'-33°20' S; 17°58'-18°11' E), which incorporates the former Langebaan Nature Reserve is situated in a semi-arid region on the western coast of the Western Cape Province and comprises an area of 24 779 ha.The vegetation is classified as Strandveld and isolated patches of Coastal Fynbos (White 1983;Acocks 1988).The park lies within the winter rainfall region of South Africa in which summers are hot and dry, and winters cold and wet.Ten animals were examined during February 1990 in this park.
The Karoo National Park (32°12'-32°20' S; 22°18'-22°39' E), comprises an area of 17 706 ha near the town of Beaufort West in the north-eastern part of the Western Cape Province.It is a semi-arid region with hot summers and cold winters, and occasional snow on the higher mountain peaks.The vegetation consists of Karroid Broken Veld (Acocks 1988).
Sixteen animals were examined for ticks in this park during February 1991.
The species and numbers of animals examined are summarized in Table 1.The animals were either shot or chemically immobilized.The larger species that were shot were processed for ectoparasite recovery as described by Horak et al. (1992) for greater kudus and the smaller animals as described by Horak et al. (1986) for scrub hares.The animals that were immobilized were carefully scrutinized for ticks.The ticks collected from the processed material, or directly from the immobilized animals, were stored in 70 % alcohol for later identification and counting under a stereoscopic microscope.A total of 14 ixodid tick species were recovered in this way.
Only four tick species were recovered from the 22 animals examined in the South African portion of the Kgalagadi Transfrontier Park (Table 2), and individual burdens were small.No ticks were collected from the single red hartebeest and the two springbok examined.The species collected, namely Hyalomma marginatum rufipes, Hyalomma truncatum, Rhipicephalus exophthalmos and Rhipicephalus theileri are all adapted to harsh climatic conditions (Howell, Walker & Nevill 1978;Walker et al. 2000).The preference of R. exophthalmos for scrub hares and R. theileri for Cape ground squirrels is evident from the collections made from these animals.The latter tick is also common on yellow mongooses, Cyn ictis penicillata, and meercats, Suricata suricatta, which share warrens with ground squirrels (Horak, Chap parro, Beaucournu & Louw 1999;Walker et al. 2000).
The species and numbers of ticks collected from animals in the West Coast National Park are summarized in Table 3. Six ixodid tick species were collected from the ten animals examined, and large numbers of H. truncatum, Rhipicephalus capensis and Rhipicephalus glabroscutatum were recovered.The distribution of R. capensis is virtually confined to the western winter rainfall region of the Western Cape Province, while R. glabroscutatum occurs not only here and in the southern Karoo, but also in the non-seasonal rainfall regions of the Western and Eastern Cape Provinces and in the Valley Bushveld of the latter province (Walker et al. 2000).The eland, probably because of their larger size, harboured considerably more adult H. truncatum and R. capensis than the gemsbok (Gallivan & Horak 1997).Conversely the gemsbok carried larger burdens of all stages of development of the two-host ticks Rhipicephalus evertsi evertsi and R. glabroscutatum.All stages of the latter tick attach around the feet  and on the lower legs of their hosts (MacIvor & Horak 1987).One of the bontebok harboured four adult R. capensis, and one of the springbok was infested with a small number of immature R. evertsi evertsi and the other with a similar number of immature R. glabroscutatum.
Seven ixodid tick species were recovered from the 16 animals examined in the Karoo National Park (Table 4).The dominant species was R. glabro scuta tum and mountain reedbuck were the most heavily infested.Five fairly rarely collected tick species were recovered, namely Hyalomma glabrum, Rhipicephalus arnoldi, Rhipicephalus distinctus, R. exophthalmos and Rhipicephalus neumanni.The adults of R. arnoldi infest Smith's red rock rabbits and the immature stages infest these animals and other sympatric small mammals (Walker et al. 2000).All stages of development of R. distinctus infest rock hyraxes (Horak & Fourie 1986;Horak et al. 1991a), and although the tick does not occur throughout the range of these small mammals its distribution is dependent on the presence of its hyrax hosts (Walker et al. 2000).Rhipicephalus neumanni is a tick of the semiarid central and western regions of South Afri ca and southern regions of Namibia (Walker et al. 2000).It and R. capensis are the only ticks of the 14 species collected that have distributions virtually con fined to the south-western regions of the subcontinent.

TABLE 1
Mammals examined for ticks in three western, semi-arid nature reserves in South Africa

TABLE 2
Ixodid ticks collected from mammals in the South African part of the Kgalagadi Transfrontier Park

TABLE 3
Ixodid ticks collected from mammals in the West Coast National Park, South Africa