Pink flamingos duck their heads beneath the still, blue waters of Sandpan in Benoni. Yellowing reeds, with streaks of healthy green not yet withered by winter, are clustered around its edges. The only sounds come from the chirping of birds. Upmarket housing estates have already encroached on three sides of the pan, with the open side left free to grow a head-high sea of grass, dotted with purple and white flowers. This is the original flora of Gauteng – the Highveld grassland. And it is the home of the African giant bullfrog.
Weighing in at more than a kilogram, it is the second-largest frog on Earth. Its thin skin makes it sensitive to toxins, so it can be used as a barometer of the health of an ecosystem – see thousands of these hopping about in spring and you know nature is fine. Its two biggest breeding grounds in Gauteng have been destroyed by shopping centres, and now it relies on three pans in Benoni.
But now hundreds of houses, anchored by a R6-billion shopping centre, are planned around two of these pans. A planned highway might also go ahead, right between Sandpan and the neighbouring Bullfrog Pan – once their largest breeding ground in the southern hemisphere.
By the 1980s, the bullfrogs had vanished from the area, killed by industrial dumping in the pans. It was only in 1995 that they were re-introduced, and with careful management their numbers have steadily grown. Now locals speak of so many in spring that it seems like "an invasion". Police even have to close roads off, says a resident. Signs on posts along the pot-holed streets of Rynfield in Benoni warn motorists to watch the road carefully. "Please protect them," they say.
All of this is thanks to the local community. Vera Hodgson of the Rynfield Agricultural and Benoni Small Farmers Residents Association says: "This is one of the very last places that they are clinging on to life. We have done so much to bring them back, but now this development is threatening all that progress."
Near endangered
Her son uses his hands to describe how big they grow – the size of a football.
The International Union for Conservation of Nature (IUCN) lists the bullfrogs as "near endangered".
The South African National Biodiversity Institute lists them as a protected species, which covers "any species which is of such high conservation value or national importance that it requires national protection", and it is on its list of locally threatened species.
Dr Jeanne Tarrant, manager of the threatened amphibian programme of the Endangered Wildlife Trust in Johannesburg, says the biodiversity institute's regulations "recommend that habitat should not be disturbed in any way that affects the species".
The problem should have been identified in the planned development's environmental impact assessment, and a solution should have been found, Tarrant says.
A similar situation occurred with the erection of a nearby petrol station on the N14 highway, she says. The environmental impact assessment found that the site would have encroached on the breeding grounds of local bullfrogs, so the developer built a small reserve to protect them.
Legislation
Hodgson says the latest development is perplexing because there are so many aspects of legislation that cover conservation. "[But] nobody cares about frogs. They are just small, and this is big money," she says.
The developer, Seedstone Fund Advisors, said they would not be able to comment this week. The final development plans were still under discussion, they said, and the project might still not go ahead.
The provincial department responsible for the environment did not respond to a request for comment.
It's not just the frogs that are at risk, so are the wetlands and Highveld grasslands in the area. Wetlands are a high priority for the departments of water and the environment, which have numerous programmes in place to resuscitate them. Wetlands act as sponges, soaking up water that they clean and then release. The department says keeping wetlands healthy is far cheaper than cleaning water later along the line.
The grasslands used to be the natural biome of Gauteng, but have been stripped away with constant development. They are natural habitats for all sorts of animals, many of which have been classified as endangered by the IUCN.
Hilton Butler, another member of the Rynfield residents' committee, says environmental concerns are being ignored by developers.
"In the past, the environment was considered in developments, but the big developments recently have set a precedent. Now the message is that development is more important than the environment," he says, pointing to an African grass owl flying above the tall grass.
A research presentation by five bullfrog experts shows that 10000 breeding adults need to be kept alive for the population not to slip into the endangered category. To ensure the species prospers, the wetlands must be conserved – if they are healthy, the bullfrogs will prosper.
But the research presentation does say that Gauteng's constant expansion will make "the persistence of bullfrog populations doubtful beyond the next 50 years".