Some of the venomous snakes of the South African bushveld areas
Kruger National Park | May 2020
Only 16 out of the 151 species of snakes found in southern Africa have venom considered to be life-threatening to humans which includes: two species of mamba, six species of cobra, coral shield cobra, Gaboon adder, puff adder, berg adder, boomslang, and two species of vine snake. The vast majority of snakes seen in the African bush are not deadly to humans (many are constrictors or have venom that does not seriously affect human beings). Less than 1% of snake bites result in human fatality. The chance of being bitten by a snake can be minimized by wearing boots when walking or hiking, keeping a safe distance away from snakes and avoid playing or trying to catch them, especially if you are not able to identify what type of snake it is. One should be very careful when moving / lifting rocks, branches or building material as snakes might use these areas to hide away. It is also important to watch carefully where you are walking and to be wearing closed shoes. At night the use of a torch is extremely important in order to avoid the possibility of stepping on a snake.
Snake venom is made up of proteins and peptides, and is stored in modified salivary glands that are situated behind the eyes, on either side of the head. Venom plays an important role in aiding snakes in defence, the capture of prey and also speeds up the process of digestion (as they are unable to chew their food).
Venom types are generally classified into four main groups namely: neurotoxic (affecting the nervous system); cytotoxic (affecting tissue); haemotoxic (affecting blood chemistry) and myotoxic (paralysis of muscle). Many snakes have a combination of different types of venoms.
In order to help you identify some of the dangerously venomous snakes found in the African bushveld, see a brief description below:
Black mamba (Dendroaspis polylepsis)
Black mambas are the largest venomous snakes found in southern Africa. The black mamba is one of the most feared creatures in Africa. Adult snakes can reach an average length of 2.5 to 3 meters, although mambas are said to reach a maximum length of up to 4 meters. They can be described as both slender and agile, with large heads, and are able to spread a narrow hood and gape to show the black colouration inside of the mouth.
They have a characteristic smile when viewed from a side profile and have a head shaped like a coffin. Their body colour can vary from a dark olive to a grey-brown or typical gunmetal grey and they have pale grey bellies.
They are generally considered to be terrestrial and feed on small mammals, but can also be found hunting squirrels and birds in trees and bushes. They are considered to be one of the most dangerous snakes in Africa due to their supposed nervous disposition and potent (neurotoxic) venom. Mambas are not often seen and are quite territorial.
Mambas are what we refer to as proteroglyphs (based on their dentition). They have short, hollow (like an injection needle), fixed, fangs that are situated at the front of the mouth.
The venom of a black mamba is generally considered to be potently neurotoxic. Symptoms of a mamba bite may include dizziness, nausea, ptosis (drooping of the eyelids), difficulty in swallowing and breathing, slurred speech and possible headaches. In cases of severe envenomation death usually results from organ failure.
Puff adder (Bitis arientans)
Puff adders are short, stocky snakes. The average adult length is in the region of 1 meter, although further north in Africa it has been reported that they could possibly get up to 1.8 meters. Puff Adders rarely get longer than 1.3 meters in southern Africa.
They are very distinctive looking snakes, with a triangular-shaped head and light chevron markings (V-shaped) on a brown and khaki background. They are extremely well-camouflaged and blend in well with their surroundings. They have keeled scales (the scale has a ridge running down the middle) on the upper surface that make them look rough. They tend to be terrestrial, spending most of their time on the ground. They are very seldom seen in trees or bushes.
Puff adders are generally fairly stationary in nature and often lie next to animal pathways waiting to ambush prey such as mice and other rodents. If one walks too close to a puff adder it may warn you of its presence by making a hissing sound (hence the name). Although they appear to be sluggish snakes puff adders are able to strike extremely quickly.
Puff adders are considered to be solenoglyphs. This means that they have long, hollow, recurved fangs (up to 2 cm long) that fold back in the mouth when it is closed. The fangs are situated near the front of the mouth.
The venom of a puff adder is considered to be cytotoxic in nature. Symptoms of a puff adder bite include extreme pain, massive swelling, the possibility of blood-blisters forming and necrosis (cell decay and tissue destruction). Although bites from this species are considered to be extremely serious most do not result in death (if proper medical help is sought). Amputation of the affected limb may occur in extreme circumstances.
Mozambique spitting cobra (Naja mossambica)
The Mozambique spitting cobra is a fairly common snake in the lowveld area. It can be fairly long (it can exceed 1.7 meters in length). They are very elegant looking snakes with a “mean” face. They are generally light brown in colouration with a salmon-pink underside and often with black stripes across the chest area. They are able to spread a wide hood.
Mozambique spitting cobras are generally nocturnal (active at night), although they can also be seen during the day on occasion. They feed mainly on frogs, toads, rodents and reptiles (sometimes even other snakes). They are often found near human habitation (in rural areas) and hide under rubble, building material etc. This is possibly the venomous snake that we encounter the most in the lodge surroundings.
They have a dentition much like the black mamba (proteroglyph), although the fangs and venom are specifically adapted to a snake that spits. The venom glands tend to be large with strong muscles to push the venom further. The venom is also more liquid so that the snake can spray it over a distance. The hole at the tip of the fang is such that it directs the venom out at a ninety-degree angle to the tooth and the aperture is slightly smaller than that of non-spitting cobras (so that there is more pressure to force the venom out). Mozambique spitting cobras are able to spray their venom even without spreading a hood. They are able to spit their venom for up to a distance of 2,5 meters.
These snakes have a predominantly cytotoxic venom (much like that of a puff adder). Venom entering into the eyes causes immediate pain, a burning sensation, chemosis (it causes the eye to ooze), swelling of the cornea, redness to the sclera (the white part of the eye) and loss of eyesight. If venom gets into the eye it needs to be washed out with running water thoroughly and the victim needs to get to a doctor as soon as possible to avoid becoming permanently blind. Even after the venom is washed out of the eye it may cause a “scab” to form over the eye, which can be seriously painful and irritating (particularly when blinking) until the eye heals fully.
Snouted cobra (Naja annulifera)
The snouted cobra (which also used to be referred to as an Egyptian cobra) is one of the larger, more impressive cobras in southern Africa. This snake can get up to 2,5 meters in length and can spread a wide hood when it feels threatened.
These snakes may come in various colour forms i.e. a beautiful golden, honey-hued colour, or a dull grey (similar to a black mamba) or even have broad, interspersed bands of black / dark grey and cream. The lighter coloured individuals often have a dark “tear-drop” under the eyes. The darker forms may have blackish bands across the chest and the underside tends to be yellowish in colour. Juveniles may have a black band across the chest. Snouted cobras can become quite thick in girth.
These snakes are usually nocturnal, but may be seen moving about on overcast days. They often bask in the morning sun close to where they live. Snouted cobras feed predominantly on toads, rodents, birds, lizards and even other snakes (they seem to be particularly fond of feeding on puff adders). They are mainly terrestrial, but may also climb into bushes or trees.
Snouted cobras have a dentition similar to mambas. These snakes have a predominantly neurotoxic venom, with some cytotoxic qualities. Snouted cobras are not spitting snakes.
Boomslang (Dispholidus typus)
The boomslang (an English translation is “Tree Snake”) is a beautiful arboreal (it lives in trees and bushes) snake with large eyes and a small bullet-shaped head. It is a long slender snake that can attain a length of up to 1.6 meters. This is one of the few snakes that are sexually dimorphic. Males tend to be bright emerald green, whereas the females tend to be brown or grey. In the western Cape region the males can be black with bright yellow, orange or green bellies. The juveniles often have bright green eyes. Boomslang have got keeled scales (like a puff adder) on the upper surface of the body which help with keeping grip when climbing tree trunks or when moving from branch to branch. When distressed these snakes may puff out their necks (in a ball shape as opposed to flattening the neck out like cobras). These snakes have got amazing eyesight and are supposedly able to see stationary objects. The positioning of their eyes and the hollow in front of the eyes gives them binocular vision and allows them to judge distance well.
These are diurnal (active during the day) and hunt birds, frogs and reptiles (chameleons in particular). They also raid bird nests to feed on the chicks.
Boomslang are considered to be fairly relaxed, placid snakes and very seldom attempt to bite people unless they are harassed or caught.
They have opisthoglyph dentition, with their short rearward facing fangs placed deep within the mouth. These fangs lie in line with the back of the eye and are grooved, as opposed to being hollow. Because their fangs are placed far back in the mouth they are considered to be “rear-fanged or “back-fanged” snakes.
The venom of a boomslang is said to be haemotoxic and causes the blood-clotting mechanism to be affected. Symptoms from a bite from this snake may take a while to appear and appear as massive internal bruising. Blood may start flowing from previous injuries or from bodily orifices. This venom is said to be highly toxic but may take many hours for the symptoms to show. Very few people die from Boomslang bites and fatalities are as a result of blood-loss.