Animals are thriving in the Cape Flats Nature Reserve, according a recent UWC survey.
Every year, the annual animal count brings students, staff and animal lovers together for a night of bundu-bashing and animal counting in the reserve and this year’s survey brought back only good news.
This year’s count saw more than 60 staff, students, hobbyists, school children and volunteers join reserve staff in the fun, setting out traps and wandering the reserve checking them.
From arachnids to sand frogs to tortoises and whip snakes, the survey revealed some interesting results.
“Older members of the community may remember how commonly 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 significantly be reduced,” said reserve manager Hestelle Melville.
“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’ve put up traps the day before.”
There has been an increase in the number of invertebrates over the years after the reserve stopped using herbicides The return of the smaller animals was followed by an increase in larger animals, like the resident caracal, water mongoose and birds of prey and the ecosystem seems fairly healthy.
Over the years, the baseline data collected has helped to assess the general health of the area and can indicate any change in the environment.
Dr Adriaan Engelbrecht, a small-mammal expert from UWC’s Department of Biodiversity and Conservation Biology, was part of the midnight group of surveyors.
He said such surveys were important o gauge the reserve’s biodiversity and conservation value.
For instance, small-mammal species such as vlei rats, (otomys irroratus), and sengis (elephantulus edwardii) only occur in ecologically intact environments. Other rodents species, such the common four-striped field mouse (rhabdomys pumilio), in turn, flourish in disturbed habitats – so a huge population of them in a particular area would indicate a general decline in habitat integrity.”
Reptile expert Dr Bryan Maritz, said protecting and managing biodiversity posed some significant challenges, especially in big and rapidly-developing cities like Cape Town.
“Without knowing which species occur in a particular area it’s impossible to tell how the different organisms are responding to current management,” he said. “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.
“For some groups of animals, the question of which species occur in an area can be very 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.”
The survey results:
A variety of reptiles counted thus far: 25 chameleons, along with egg-eaters and cross-marked whip snakes and various gecko and other lizards; and 12 angulate (chersina angulata) tortoises (seven males, four females and one sub-adult, of which the sex couldn’t be determined).
* 35 bird species.
* Among the mammals, five rodent species (mice, gerbils, rats and shrews).
* Among the amphibians, eight sand frogs – during this very dry season.
* Among the invertebrates, several spiders and insects were counted, including 10 species of butterflies, and many other crawling creatures which still need to be identified.