Lethal but lazy

What looks like a dead brown leaf in a direct line above the green leaves is in fact the head of a Gaboon adder. Blessed with near perfect camouflage for its preferred habitat on forest floors  and possessing a massively venomous bite this species ought to be the ultimate predator.

However as the Guide to the Reptiles of Southern Africa puts it - "Gaboon adders lead an extremely low-energy lifestyle and are probably the most sedentary snakes in the world." This specimen was kept in a low walled but unroofed enclosure at the St Lucia Crocodile Centre - no roof was needed as they simply do not climb at all! I've been told that even a normal height curb stone is enough to stop them in their tracks.

Although relatively common in some other parts of Africa populations in South Africa have come under increasing pressure owing to the destruction of coastal forest habitat.