[8] Lenk et al. (1999) discovered genetic differences between the two conventionally recognized subspecies of B. g. gabonica and B. g. rhinoceros.

As of 1909, Gaboon referred to the northern portion of French Congo, south of the equator and lying between the Atlantic Ocean and 12°E longitude.

The maximum total length of this species is often cited as 205 cm (81 in) for a specimen collected in Sierra Leone, but individuals from this locale are now reclassified as Bitis rhinoceros.

[12] A large specimen of 1.8 m (5.9 ft) total length, caught in 1973, was found to have weighed 11.3 kg (25 lb) with an empty stomach.

[5] The color pattern is striking in the open, but in nature, typically among dead leaves under trees, it provides a high degree of camouflage; in a well-kept cage with a suitable base of dried leaves, overlooking several fully exposed specimens completely is easy.

[citation needed] The pattern consists of a series of pale, subrectangular blotches running down the center of the back, interspaced with dark, yellow-edged, hourglass markings.

The flanks have a series of fawn or brown rhomboidal shapes, with light vertical central bars.

[16] This species can be found in Guinea, Ghana, Togo, Nigeria, Cameroon, Equatorial Guinea, Gabon, the Republic of the Congo, the Democratic Republic of the Congo, northern Angola, the Central African Republic, South Sudan, Uganda, Kenya, eastern Tanzania, Zambia, Malawi, eastern Zimbabwe, Mozambique, and northeast KwaZulu-Natal Province in South Africa.

Mallow et al. (2003) also list Sierra Leone, Senegal, and Liberia in West Africa.

[2] The Gaboon viper is usually found in rainforests and nearby woodlands, mainly at low altitudes,[15] but sometimes as high as 1500 m above sea level.

In Zimbabwe, they only occur in areas of high rainfall along the forested escarpment in the east of the country.

In Kumasi, Ghana, they were regularly killed by ranch hands around some stables in an open field with the forest some 500 meters away—a sign that they were hunting rats in the grassland.

[18] If threatened, Gaboon vipers may hiss loudly as a warning, doing so in a deep and steady rhythm, slightly flattening the head at the expiration of each breath.

[5][12][18] Despite this, they are unlikely to strike unless severely provoked;[5] however, they are one of the fastest-striking snakes in the world, so care should be taken in handling them.

In Lane (1963), Ionides explained he would capture specimens by first touching them lightly on the top of the head with a pair of tongs to test their reactions.

Hissing and anger were rarely displayed, so the tongs were usually set aside and the snakes firmly grasped by the neck with one hand and the body supported with the other as he picked them up and carried them to a box for containment.

[20] They also hunt many different species of rodent, including field mice and rats, as well as hares and rabbits.

[20] More unlikely prey items, such as tree monkeys, the Gambian pouched rat, the brush-tailed porcupine, and even the small royal antelope have been reported.

Occasionally, the combatants tire and break off the fight by "mutual consent", resting for a while before resuming once more.

[21] Bites from this species are extremely rare because these snakes are seldom aggressive and their range is mostly confined to rainforest areas.

[5] Spawls and Branch (1995) state from 5 to 7 mL (450–600 mg) of venom may be injected in a single bite.

Marsh and Whaler (1984) wrote that 35 mg (1/30 of the average venom yield) would be enough to kill a man of 70 kilograms (150 lb).

In humans, a bite from a Gaboon viper causes rapid and conspicuous swelling, intense pain, severe shock, and local blistering.

Other symptoms may include uncoordinated movements, defecation, urination, swelling of the tongue and eyelids, convulsions, and unconsciousness.

[4][12] Local tissue damage may require surgical excision and possibly amputation to any affected limb.