Scientifically known as Bitis gabonica, Gaboon viper is one of the Viper species found within the rainforests and savannahs of sub-Saharan Africa. Scary as they are, it always a magical experience to encounter them during Uganda safaris.
They are sometimes known as butterfly adder, Gaboon adder, forest puff adder and swampjack. Their name originated from a Portuguese word “Gabão” meaning the estuary on which Libreville Town was built on Gabon. Gaboon was the area known as the Northern part of the French Congo, South of the Equator and lying near the Atlantic Ocean.
Gaboon vipers occupy different habitats that include rainforests and nearby woodlands (mostly around low attitudes) although sometimes go to places of higher elevations. Others are found in secondary thickets, cashew plantations, under bushes, agricultural lands as well as areas near grasslands.
Just like all Viper species, the Gaboon vipers are poisonous and are the largest member of the Bitis genus. Interestingly, they have the longest fangs measuring up to 5 centimeters (2 inches) long and surprisingly the highest venom yield of any snake species.
So far, two sub-species are presently recognized including the nominate sub-species you are about to discover. Adult Gaboon vipers measure an average length of 125 to 155 centimeters (4 to 5 feet) (including body and tail) with the maximum total length being 205 centimeters (81 inches) for a certain specimen identified in Sierra Leone.
Gaboon vipers generally have large and triangular heads whereas their necks are usually narrowed to almost one-third of the total width of their heads. Surprisingly, they have a pair of horns between their raised nostrils. Their eyes are large and moveable and surrounded by about 15-21 circumorbital scales. Additionally, there are over 12 to 16 interocular scales found across the top of their heads and their fangs sometimes reach length of 55 millimeters (2.2 inches), thus said to be the longest of any poisonous snakes.
Much as it is often confusing, they exhibit sexual dimorphism with the different sexes identified by the length of their teeth in relation to the total body length, and it is about 12% for males and 6% for females. Not only that, adult females are very heavy and plump.
These snakes can grow to an average length of 80 to 130 centimeters (32 to 51.1 inches) with a maximum total length being 175 centimeters (69.3 inches) thus they may possibly grow larger still. There have been rare cases of some of them measuring over 1.8 meters (6 feet) or even up to 2 meters (6.5 feet).
The longest recorded Gaboon Viper in history measured about 1.8 meters (5.9 feet) and this was in 1973 and was said to have weighed up to 11.3 kilograms (25 pounds) yet with an empty stomach, thus expected to exceed that when fully satisfied.
The color of their body patterns are made up of several pale and sub-rectangular stripes running down the center of their backs and are interspaced with dark and yellow-edged hourglass markings. Their bellies are pale with uneven brown or black patches while their heads are white or cream with fine and dark central lines.
These snakes are primarily nocturnal and have a tendency of moving slowly and being placid, and interestingly hunt by ambushing their prey. Usually spend long periods motionless as they wait for their suitable prey to pass although sometimes are known to hunt actively, mainly during the first 6 hours of the night.
When sexually active, the male Gaboon vipers participate in combat, which begins by rubbing their chins along the back of the other males. The second one raises the head as high as possible. Their gestational period is 7 months, thus are said to have two to three breeding cycles although up to five are possible.
When scared, they hiss loudly with steady rhythms to warn enemies then slowly flatten their heads at the expiration of each breath. Even with this, they rarely strike unless are continuously provoked. However, it should be noted that Gaboon vipers are one of the fastest-striking snakes on earth thus so much care should be observed when handling them.
Besides Uganda, these snake species can be spotted in several African countries that include Eastern Zimbabwe, Guinea, Sierra Leone, Ghana, Republic of Congo (Congo Brazzaville), Kenya, Liberia, Mozambique, Democratic Republic of Congo, Cameroon, Zambia, Northern Angola, eastern Tanzania, South Sudan, Guinea, Togo, South Africa and Togo.
Due to their large and heavy sizes, matured Gaboon vipers have no problem swallowing an animal that is as large as a fully grown rabbit. However, they consume several mammals and birds, especially Doves, numerous species of rodents (field rats and mice) and hares among others.