Reptiles, including the cross-marked whip snake as well as 35 bird species and 10 species of butterflies, are thriving at the UWC Cape Flats Nature Reserve, with a marked increase in animal numbers recorded.
The reserve acts as a resource for plant and animal samples for research projects to schools and tertiary institutions.
Every year, the Annual Faunal Survey brings students, staff and animal lovers together for a night of animal counting in the 34-hectare reserve to provide an idea of how many animals live there.
This year, more than 60 participants found 25 chameleons, egg-eaters, cross-marked whip snakes, geckos and lizards, plus 12 Angulate tortoises.
About 35 bird species were found. Among the mammals were five rodent species including mice, gerbils, rats and shrews, and among the amphibians were eight sand frogs.
Of the invertebrates, many arachnids (spiders) and insects were counted, including 10 species of butterflies, and crawling creatures yet to be identified.
There has been an increase in the number of invertebrates over the years, after the application of herbicides was discontinued. The return of the smaller animals was followed by an increase in larger animals, such as the resident caracal, water mongoose and birds of prey.
Reserve manager Hestelle Melville said: “The dwarf chameleon occurred in any Cape Town garden just a decade or two ago. And when we think of how rarely we see them today, it can give you a good indication of how quickly animal species can be lost or their numbers reduced.
“We are very pleased with the results after we had staff and community members spending a late night and early morning in the reserve collecting animal life in the designated areas where we’d put up traps the day before.”
UWC’s Department of Biodiversity and Conservation Biology (BCB) small mammal expert Adriaan Engelbrecht said the surveys also help to assess the conservation value of the reserve.
“For instance small mammal species such as vlei rats and sengis (Elephantulus edwardii) only occur in ecologically intact environments.
"Other rodents species, such as the common four-striped field mouse (Rhabdomys pumilio), flourish in disturbed habitats - so a huge population of them in an area would indicate a general decline in habitat integrity.“
Reptile expert Bryan Maritz, also from the BCB, said protecting and managing biodiversity poses some significant challenges, especially in big and rapidly-developing cities.
“Without knowing which species occur in a particular area it’s impossible to tell how the different organisms are responding to current management. Also, it’s impossible to tell if our own activities have resulted in any species disappearing from particular areas.”
The only way to gather that kind of information is with regular detailed surveys, Maritz said.
“For some groups of animals, the question of which species occur in an area can be tricky to answer. For example, many reptile species are secretive in nature, and might live in an area without being noticed by humans for extended periods.”