The World Heritage Site of iSimangaliso Wetland Park is, by some accurate estimates, the most species-rich protected area in Southern Africa. I spent a few days recently with Xander Combrink, the park’s threatened species expert, and his three sons, as we went looking for snakes to photograph in the park I asked him some questions.
Scott Ramsay: Which are some of the most special snakes of iSimangaliso?
Xander Combrink: In terms of snakes, the first one that comes to mind is the Gaboon adder (Bitis gabonica). iSimangaliso is the only protected area in South Africa where gaboon adders are found.
It used to be a red data species but it’s now been down-listed because of the entire population in South Africa lies within iSimangaliso, a protected area.
It’s an exceptional looking snake because it’s the largest adder in the world, and it has the longest fangs of any snake in the world. It’s highly venomous with a combination of both neurotoxic and cytotoxic, so it attacks both the nervous and tissue system.
If you get bitten, and don’t get treatment, you would probably die, or spend months in hospital. Its venom is highly lethal but there are few fatalities, mostly because Gaboon adders hide on the forest floor and are lazy and unaggressive.
But they can take some huge prey. For instance we recorded a gaboon viper taking a baby red duiker. It probably bit the duiker in the belly. If the duiker runs too far after being bitten, the snake won’t be able to eat it. So the venom’s got to be so toxic that the duiker’s dies within ten metres or so. It’s probably a very quick-acting venom and then the snake will just follow the scent trail to the prey.
Gaboon vipers are ambush predators. They just lie and wait, not moving for weeks at a time. We studied a gaboon that didn’t move for 83 days. Every second day we went to take a photo of it, and for 83 days that snake did not change even its body position.
Then, when a squirrel, bird or duiker walks past, it strikes. It’s a bit like a croc, a perfect predator for its environment, very cryptic. It’s just an unbelievable predator.
SR: What about other special snakes at iSimangaliso?
XC: In terms of other snake species, a really cool one is the striped harlequin snake, a red data species. We’ve had two or three recordings in Mkhuze section, a very pretty little snake.
Then the pygmy wolf snake is also rare, it’s found from Mkuze to St Lucia, and maybe southern Mozambique, so in South Africa it’s probably only found in iSimangaliso.
The East African shovel snout; its entire range in South Africa is also within iSimangaliso.
Then the coral rag skink. It’s not a snake, but it’s only found at Black Rocks in iSimangaliso, nowhere else in the park or the country! It’s only found much further north at Inhambane in Mozambique.
SR: And what about the crocodiles of iSimangaliso?
XC: iSimangaliso has the highest number of crocs in a single water body – Lake St Lucia – so it’s the single biggest population in the country, but Kruger has more crocodiles overall, but they are spread out over river systems which are not interconnected. The crocs at iSimangaliso are the most southern breeding population and we also have the largest estuarine croc population in Africa, so that’s important.