Reptiles
Gaboon Viper
Bitis gabonica · also called Gaboon adder, forest puff adder, butterfly viper
The Gaboon viper is a study in contradictions: it carries the longest fangs and one of the largest venom loads of any snake on Earth, yet it is so calm and so perfectly camouflaged that people regularly walk straight past — or over — one without knowing it is there.
Overview
Gaboon vipers live on the floor of Central and West African rainforest and the moist woodland and plantation edges around it. They are nocturnal ambush predators, spending the day coiled motionless in the leaf litter and hunting at night by lying in wait along animal trails. They are almost entirely terrestrial and move slowly, in a straight “caterpillar” crawl, rarely travelling far.
The equipment
- Fangs up to 5 cm long — the longest of any snake — hinged so they fold flat and rotate forward to strike.
- A huge venom yield: a single bite can deliver 5–7 millilitres, and exceptionally much more, of a venom that destroys tissue and disrupts blood clotting and blood pressure.
- A short, thick, heavy body — the Gaboon viper is the bulkiest viper in Africa — with a broad, flat, triangular head and small horn-like scales on the snout in the eastern form.
Camouflage as a strategy
The Gaboon viper’s defence is not speed or venom but disappearing. Its skin bears a geometric mosaic of buff, brown, purple, and cream that reproduces the look of scattered dead leaves in dappled light. A resting Gaboon viper is effectively undetectable, which both hides it from predators like honey badgers and mongooses and lets prey wander within striking range.
Hunting
When a rodent, ground bird, or hare comes close, the viper strikes with startling speed for such a sluggish animal, drives the long fangs deep, and — unusually for a viper — often holds on rather than releasing and tracking. The large venom dose kills quickly, and the snake then swallows the prey, which can be surprisingly large: monkeys and the young of small antelope have been recorded.
Reproduction
Gaboon vipers are live-bearing, giving birth to a litter of roughly 8 to 40 young after a gestation of about a year. The neonates are already fully venomous and independent.
Status
The Gaboon viper is listed as Least Concern and remains widespread, but it is declining locally through rainforest clearance, road mortality, killing by people, and collection for the international pet trade, where its size and pattern make it sought after. Its slow movement and reluctance to flee also make it easy to catch — and easy to run over on forest roads.
Gaboon Viper: common questions
How long are a Gaboon viper's fangs?
Up to about 5 centimetres — the longest fangs of any snake in the world. They fold back against the roof of the mouth when not in use and swing forward as the snake strikes. Combined with a huge venom supply, the long fangs let the Gaboon viper inject a deep, large dose in a single bite, then hold on to the prey rather than releasing it as many vipers do.
Is the Gaboon viper aggressive?
The opposite — it is one of the most placid venomous snakes. It relies on camouflage rather than flight, so it stays motionless and lets threats pass, and it is slow to strike even when disturbed. Most bites happen when someone treads directly on a hidden snake or tries to handle one. When it does strike it is very fast and, unusually, may keep hold of what it has bitten.
How dangerous is a Gaboon viper bite?
Potentially very serious, though bites are rare because of the snake's habits and forest habitat. The venom is mainly cytotoxic and haemotoxic — it destroys tissue, causes massive swelling and bleeding, drops blood pressure, and can lead to shock and organ failure. The enormous injected volume makes envenomation severe, and antivenom plus intensive hospital care is needed. Fatalities do occur, especially where medical help is far away.
Why is the Gaboon viper so hard to see?
Its skin carries a precise pattern of pale and dark rectangles, triangles, and hourglass shapes in browns, purples, and cream that exactly mimics a patch of sun-dappled leaf litter. Lying still on the forest floor, a two-metre snake becomes genuinely invisible from a metre away. This lets it ambush prey that walks right up to it, and it is the snake's primary defence — it simply is not detected.