More than 340 spiders species have been recorded from three national parks over a period of 20 years. Invertebrates include more than 80% of all animals, yet they are severely under-represented in studies of southern African diversity. In the past invertebrates were largely ignored in conservation endeavours. But conservation biologists are starting to recognize the importance of the invertebrate component in the functioning of healthy ecosystems. Due to their diversity any approach to conservation needs to take into account the composition of invertebrate fauna as well. | |
Several projects, as part of the South African National Survey of Arachnida (SANSA) are underway to determine the diversity of the Arachnida fauna of South Africa. One such a project deals with inventories of the Arachnida in conserved areas. The arachnids constitute an abundant and highly successful group of invertebrate animals. Meaningful conservation cannot take place if species involved are not known. Therefore, surveys become more important, especially in reserved areas where conservation strategies are already in place.
The first survey of spiders was undertaken to determine the diversity of the spider fauna of the Mountain Zebra National Park (Dippenaar-Schoeman 1988). The second project was a survey of the spiders of the Karoo National Park (Dippenaar-Schoeman et al. 1999) and the third survey published results of spiders collected over a period of 16-years from the Kruger National Park, South Africa (Dippenaar-Schoeman et al. 2003) (Table 1).
| Mountain Zebra | 30 | 74 | 3.7 |
| Karoo | 38 | 5.8 | |
| Kruger | 40 | 7.6 | |
The parks are home to some very large and interesting spider species. One of the largest ground dwellers is the baboon spiders that live in silk lined burrows in the ground. The horned baboon spiders are especially a great attraction. A total of 10 baboon species has so far been collected from the National Parks. These spiders are protected due to pet trade demands. A second group of large ground dweller is the trapdoor spiders. This group of spiders lives in silk lined burrows and close the entrance with intricate woven trapdoors. On the foliage we find the large huntsman spiders of the family Sparassidae. Some of them can reach a body and leg size of 120 mm. The nursery web spiders of the family Pisauridae are another group of large spiders. Some species are known as fish eating spiders, catching small fishes in freshwater ponds, while other make large funnel webs in old mammal burrows. The web spiders are represented by some very large spiders constructing webs between the vegatation. The golden orb web spiders Nephila spp. of the family Tetragnathidae is our largest orb-web spider making golden silk webs between trees. The bark spiders (Caerostris spp.) do not have long legs but very compact bodies. They construct their large orb-webs at night and during the day resembles a piece of bark. A free wandering group of spiders, the jumping spiders of the Salticidae is not the largest spiders in size but in diversity. One of the largest salticids species (Hyllus sp.) has been recorded from the Kruger National Park.
Surveys continue to enable us to obtain enough data on the conservation status of these spiders.
References:
Dippenaar-Schoeman, A.S. 1988. Annotated check list of the spiders (Araneae) of the Mountain Zebra National Park. Koedoe 31: 151-160.
Dippenaar-Schoeman, A.S., Leroy, A., De Jager, M. & Van den Berg, A. 1999. Spider diversity of the Karoo National Park, South Africa (Arachnida: Araneae). Koedoe 42: 31-42.
Dippenaar-Schoeman, A. S. &. Leroy, A. 2003. A check list of the spiders of the Kruger National Park, South Africa (Arachnida: Araneae). Koedoe 46: 91-100.
Dippenaar-Schoeman, A.S & González Reyes, A.X. 2006. South African National Survey (SANSA): Solifugae (sun-spiders) of the national parks and reserves of South Africa (Arachnida, Solifugae). Koedoe 49: 29-38.
Dippenaar-Schoeman, A. S. 2006. New records of 43 spider species from the Mountain Zebra National Park, South Africa (Arachnida: Araneae). Koedoe 49: 23-28.
Projects in progress:
Surveys arid parks
Table Mountain National Park
Kruger National Park
Golden Gate National Park
