Southern Africa's Threatened Wildlife
The IUCN came up with the idea of compiling lists of threatened wildlife, as a means of drawing the attention of citizens and governments to the plight of species faced with extinction. These lists became known as "Red Data Books", and the first internationally applicable RDB was published in July 1966. The "Red" stands for "Danger", and the concept was subsequently adopted by many different countries, which then produced their own regional RDBs. They are very important publications, as they point the way to the protection of biological diversity, one of the crucial issues facing mankind today.
The Red Data Books are the best available scientific opinions on the nature and degree of threat to various groups of living organisms. Usually they deal with the more conspicuous life forms, like mammals, birds, reptiles, amphibians, fishes, and sometimes plants. The Red Data Books point the way for government agencies charged with environmental protection, as well as for non-government citizen groups concerned about maintaining biodiversity. Action to protect threatened species listed in Red Data Books inevitably benefits the ecosystems and habitats in which those species live.
For example, to save Bengal Tigers in India you have to set aside forest reserves in which they can live. By doing so, you automatically confer protection on thousands of different plants, mammals, birds, insects and other creatures that occur in those forests. To protect Blue Swallows in southern Africa you have to establish reserves on undisturbed montane grassland, and every living organism in that grassland biome is protected too. The Red Data Books, and the importance they place on the need to take action when any species is threatened, are thus very important weapons in our battle to fight for the biodiversity of our planet.
As a means of assessing the status of populations within a given area, the IUCN uses the following categories in Red Data Books: these categories reflect the status of the species only within the area under review, and it is sometimes the case that species which are threatened in one region may have secure populations in other areas.
EXTINCT. Species for which there is a historical record, but which no longer exist in the area dealt with. Fossil forms are not included. Some species may be locally extinct, but have existing populations elsewhere.
ENDANGERED. Species in danger of extinction, and whose survival is unlikely if the causal factors continue operating.
VULNERABLE. Species which it is believed will move into the endangered category if the causal factors for their decline continue operating.
RARE. Species with small populations which are not at present endangered or vulnerable, but which are at risk. Often, the available suitable habitat, for a particular species, may be so limited within a region that only small populations can exist. Certain species require such large territories, or may have very specialized habitat requirements, that they can only occur in low densities.
(The term THREATENED can be used as a collective description for species which are Endangered or Vulnerable, and is used in that sense in this book).
OUT OF DANGER. Species formerly listed in Red Data Books, but whose status has improved, or has been re-assessed.
INDETERMINATE. Species which might be worthy of inclusion in one of the threatened categories, but for which insufficient information is available to assess their status. Such species should be priorities for research effort.
REPTILES AND AMPHIBIANS
The South African herpetofauna [reptiles and amphibians] is rich and diverse, having no less than 301 species of reptiles and 95 species of amphibians. The SARDB - Reptiles and Amphibians (R & A) lists one extinct, six endangered and fifteen vulnerable species. Of the latter, three [Cape Sand Snake, Methuen's Dwarf Gecko and Bouton's Skink] have been omitted from this booklet, and several others have been grouped together to save space.
Reptiles and amphibians are generally creatures of low mobility; they also exhibit a high level of endemicity, which means "native, restricted or found only in a particular locality or area". Thus the SARDB - R & A makes extensive use of the category "Restricted", meaning "endemic and localised within limited geographical areas". None of the restricted species are dealt with in this booklet.
In South Africa seven highly sensitive areas have been identified where the herpetofauna is especially threatened. An example of one of these is the Cape Peninsula and adjacent lowlands, where human settlements and agricultural development have caused major changes to the original ecosystems. Here there are no less than four endangered species [Cape Platanna, Micro Frog, Table Mountain Ghost Frog, Geometric Tortoise] and two vulnerable species [Cape Rain Frog, Cape Sand Snake]. Because of their restricted ranges and low mobility, Reptiles and Amphibians are particularly sensitive to loss of habitat. <
The Tsodilo Hills Gecko Pachydactylus tsodiloensis is found only at the remote Tsodilo Hills in north-western Botswana. Whilst not currently threatened this little reptile would fall under the "restricted" category. Of the several other reptiles with limited distribution in Botswana, the Makgadikadi Spiny Agama (a sub-species of a more widely distributed form) is found only around the huge salt pans from which it derives its name, and may be threatened by the present Soda Ash project.
SUNGAZER (GIANT GIRDLED LIZARD). . . . . . . . . . . . . Cordylus giganteus
ARMADILLO GIRDLED LIZARD . . . . . . . . . . . . . . Cordylus cataphractus
These two related lizards are found in two quite different regions of South Africa and face two kinds of threats, both of them arising from human activities.
The Sungazer is endemic to the grasslands of the northeastern Orange Free State, western Natal and southeastern Transvaal. They are large lizards that live in burrows dug into the soil on flat or sloping veld, especially Themeda triandra grassland. The burrows help the lizards cope with extremes of heat in summer and winter, and it is thought that they stay below ground for the coldest months of the year. They are active during the day when they sit and wait for prey to come to them. During summer they feed on large quantities of termites. Females give birth to 1-4 live young.
Threats to the Sungazer come mainly from habitat loss due to agriculture, mining and urban development To a lesser extent the pet and muthi trades and possibly insect and rodent control operations may also be aggravating factors. The highveld grasslands are under great pressure from agriculture, and at least 50% of the arable area is already cultivated. Control of gerbils and mongooses by fumigation of burrows may be a threat to Sungazers, while the use of pesticides on agricultural crops and termites no doubt reduces the amount of food available. The great coal deposits of the southeastern Transvaal are future energy sources for South Africa, and a number of giant power stations are being constructed, some of them in areas where Sungazers occur. At Majuba power station Eskom created a 400 ha reserve for Sungazers displaced by the development - lizards have been successfully relocated to this reserve, and a total of 1 500 burrows has been counted in the sanctuary.
By contrast, the Armadillo Girdled Lizard is not threatened by habitat loss or change in the extensive area of the western Cape where it occurs, but rather by excessive illegal collecting for the international reptile trade. These lizards live in groups in rock cracks, and when handled exhibit a peculiar defence action by gripping their heavily armoured tails in their jaws to protect their soft underparts. They are slow-moving, easy to catch, become very tame in captivity, and hence are so attractive to the pet trade. Strict protection is conferred on the Armadillo Girdled Lizard by the Cape Provincial Ordinance.