a berg adder at Mont Rochelle, near Franschhoek
Berg Adder. pic by Jens Dahlberg.

On the differences between Berg Adders & Puff Adders.


Sightings of snakes on Table Mountain are rare. I don't know how many hundreds of times I have walked Table Mountain over the decades. But I can count how many snakes I've seen on it. Four. A mole snake, cobra, puff adder - and March 2017, a berg adder.


There are about 22 recorded species on Table Mountain. It's more likely though that they're seen by Capetonians in their gardens, especially after mountain fires; there are also small ones in shallow Kirstenbosch streams. 


In the last month I've seen three berg adders - in Jonkershoek, Stellenbosch; and on Mont Rochelle, near Franschhoek; and then most recently this one, caught on video high up Kasteelspoort, Table Mountain. It looks like it is hunting lizard.

Initially I thought the type of snake on those last three occasions were young puff adders. But after taking more of an interest I notice their markings are subtly different. And by comparison, the Berg Adder, sometimes called a Mountain Adder, is a relatively small snake, around 30 - 50 cm in length.  (10 - 20 inches.) You could almost say cute.


Cuteness factor is probably not strong reason for the species' mysterious evolution.   Interestingly, although adders' embryos develop inside eggs, the mother snake bares her eggs within her, giving birth to live young. This is reckoned to be a potent factor in the adders’ survival - a brilliant achievement in the face of humanity's deadly fear of snakes, and the Anthropocene's assault on biodiversity.


Berg Adders enjoy relaxing in the sun. If you disturb them they’ll hiss. Step too close and there’s a good chance you’ll get bitten.


Their venom is unusual. Other vipers, like the gaboon adder and puff adder, release a mainly cytotoxic venom, which damages the tissue cells, causing pain, swelling, blisters.  However Berg adders release a combination of this with neurotoxic venom, like that of some cobras and mambas, and which affects the respiratory system.


Their victims struggle with pain and swelling; there's some tissue damage, though not too severe. Quite often they may have difficulty breathing. Vision is impaired, eyelids droop. Temporary blindness is also a symptom. Death in humans is highly uncommon.   


If the bite goes unnoticed at first, a bit later it may seem like an scratch or small superficial wound. Small children bitten by a berg adder are at higher risk of being seriously affected.


Get medical attention ASAP.


As you can see from the video, this snake didn't seem bothered by me. It must have been aware I was there. I'd like to think that it didn't feel threatened. But who knows? I guess the thing is, respect them when you see them. And just let snakes be snakes.   


  • The puff adder’s markings form chevron shapes.
  • Berg adder’s eyes are set slightly more forward than a puff adder
  • It has more of a lance-shaped head.
  • It’s nowhere near as big.
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