This thread is in dire need of a pic. I shot this one of a captive Gaboon in St Lucia, Northern Natal.
Amazing camouflaging capability is possessed by this animal. I have an idea that the Samango monkeys can only spot it when it moves, for when it is motionless I am sure it is invisible!
The biggest among African vipers, this viper can reach 180 cm in length. The fangs may reach a length of 55 mm, the longest of any venomous snake, not just in South Africa. As previously mentioned, they are usually found in rainforests and nearby woodlands, mainly at low altitudes, in South Africa exclusively in the north east of KZN.
Primarily nocturnal, they have a reputation for being slow-moving and placid. They usually hunt by ambush, often spending long periods motionless, waiting for suitable prey to happen by; its colour pattern giving it excellent camouflage. On the other hand, they have been known to hunt actively, mostly during the first six hours of the night. Following a strike, they tend to hold on to their prey until it is dead. Prey is also lifted off the ground to prevent it from struggling effectively. Anything large enough to pose more of a threat is released and searched for after a few minutes when incapacitated by the viper’s venom. These snakes feed on a variety of birds and mammals.
The eyes of the Gaboon viper is its most striking feature. It was therefore not a surprise to learn that this snake has a wider range of eye movement than other snakes. Along a horizontal plane, its eye movement can be maintained even if the head is rotated up or down to an angle of up to 45°. If the head is rotated 360°, one eye will tilt up and the other down, depending on the direction of rotation. Also, if one eye looks forwards the other looks back, as if both are connected to a fixed position on an axis between them. In general, the eyes often flick back and forth in a rapid and jerky manner. When asleep, there is no eye movement and the pupils are strongly contracted. The pupils dilate suddenly and eye movement resumes when the animal wakes up.
Gaboon vipers are usually very tolerant snakes, even when handled, and rarely bite or hiss. However, bad-tempered individuals do occur. If threatened, they may hiss loudly as a warning, doing so in a deep and steady rhythm, slightly flattening the head at the expiration of each breath. They are unlikely to strike unless severely provoked. The venom itself is not considered particularly toxic. However, the venom glands are enormous and produce the largest quantities of any venomous snake. Together with the potential depth at which the huge quantities of venom can be delivered, such bites often has fatal consequences. Like many other vipers, its venom is a cell-destroying toxin, causing swelling, necrosis, gangrene and later shock and possibly death.