Africa is home to a remarkable diversity of snake species, each with its own unique characteristics, behaviors, and ecological roles. While some, like the black mamba and puff adder, are notorious for their potent venom and the danger they pose to humans, others, such as the African house snake, are harmless constrictors that play a vital role in controlling rodent populations. This article explores the fascinating world of African snakes, highlighting some of the most notable species and their distinctive traits.
Think of Africa, and snakes perhaps aren’t the first wildlife that springs to mind. Not with lions, leopards, rhinos, etc.
There are about 600 species of African snakes in Africa, and out of all of them, only a small amount are venomous - most of the snakes in Africa are harmless to humans.
There was an error submitting your feedback. You are not very likely to return home from your safari with packs of snake pictures, even though there are more than 160 snake species in Africa. These reptiles are not seen by travellers very often.
Here, we look at a poorly known group previously included within Colubridae as a ‘subfamily’. They’re often termed African water snakes (or watersnakes) and all species (five have been named to date) are included in the genus Grayia. Regarded as a subfamily within Colubridae, the group is thus Grayiinae. In taxonomic systems where Colubridae is restricted to the ‘Coluber group’ alone (and where what used to be Colubridae is Colubroidea), they’re Grayiidae, the grayiids.
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I should also add that I find ‘African water snake’ clumsy and unlikeable - it’s just too generic - and would prefer it if we adopted an African name for the group.
Grayia snakes are robust and large, reaching 1.7 m and even 2.5 m in a few places in western Africa. Relatively little is known about their natural history, they’re regarded as elusive, and they inhabit places - seasonal swamps and watercourses - where they can be hard to see and find.
But as suggested by the common name, African water snakes are semi-aquatic and eat fish, frogs and tadpoles. A study of G. smythii in Nigeria demonstrated Tilapia and the catfish Clarias to be the main fish prey, with Xenopus tropicalis - tadpoles as well as metamorphs - being the frog the snakes ate the most. This diet appears typical of G. smythii, at least, across its range.
On natural history, Grayia is known to be highly aquatic but also to be a good climber that drops into the water from overhanging branches when alarmed. It’s said to hunt underwater at night and a belief encountered in the Lunda area of Angola is that the snakes hunt in pairs.
This is of special interest given suggestions that social hunting might be present in certain snake species. Otters are reported to eat Grayia trapped in nets, and the crocodiles Mecistops and Osteolaemus prey on them too.
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Outside of ethnozoological data, Godfrey & Luiselli (2001) reported that herons and Nile monitors Varanus niloticus are also predators of these snakes and it’s been suggested that cobras - some of which forage aquatically - might also predate on them.
Grayia has always been difficult to place phylogenetically. Though (as discussed above) conventionally lumped into the great, sprawling, traditional version of Colubridae and regarded as somewhat nondescript, it’s become more obvious as more evidence has come in that it’s unusual and distinctive.
These are big and robust snakes relative to standard ‘colubrids’ and their semi-aquatic habits are consistent with views that aquatic habits might be archaic - more ‘ancestral’ - for colubroids. Hemipenis anatomy in snakes provides a great deal of phylogenetically important information and the hemipenis of Grayia differs importantly from that of most other colubroids: in many, the hemipenis is asymmetrical whereas it’s symmetrical and has a forked sulcus spermaticus in Grayia.
Add all of this together, and we have the idea of a distinct group that perhaps diverged early in evolutionary history from the lineage that includes most other colubroids.
But as our understanding of caenophidian phylogeny, diversity and anatomy has improved (and as views on how taxonomy should reflect phylogeny have changed too), it’s become increasingly realized that ‘Colubridae’ of tradition should be split up. In part this is because it was polyphyletic, various of its constituent groups being closer to elapids (cobras, mambas and kin) than to the Eastern racer Coluber constrictor, the ‘core’ animal of Colubridae. And it’s also because the groups are sufficiently diverse - in all measures - to be considered ‘families’ all their own.
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For the latter part of the 20th century at least, this group was interpreted as including basically all caenophidian snakes* that weren’t filesnakes, viperids or elapids. I like Gower et al.’s (2023) characterisation of this situation… “Snake biologists understood that this was unsatisfactory, but they were somewhat overwhelmed by the morphological and ecological diversity of these many hundreds of species, and so put up with the situation while continuing their research” (p.
In 1858, German-born British zoologist Albert Günther named a new snake that he regarded as worthy of its own genus: Grayia silurophaga, ‘Gray’s catfish eater’. This later proved synonymous with Coluber smythii… which thus became Grayia smythii.
‘Smythii’, incidentally, almost certainly honours Norwegian botanist Christen Smith (1785-1816) - he collected the type specimen on Tuckey’s expedition and somehow died on the same trip - and thus should really be ‘smithii’.
Annoyingly, ‘smythii’ and ‘smithii’ are both used in the literature on this snake, as are their variants ‘smythi’ and ‘smithi’ (I’m sticking with smythii here as I still see it as the name that’s most prevalent in the literature).
Additional Grayia species were named during the 1860s and 90s: Caesar’s African water snake G. caesar by Günther in 1863*, the Ornate African water snake G. ornatus by José Vicente Barbosa du Bocage in 1866, and Tholloni’s African water snake G. tholloni by François Mocquard in 1897.
* Actually, he named it Xenurophis caesar.
A phylogenetic analysis published this year (Chaney et al. 2024) found G. smythii and G. ornata to be sister taxa, and G. caesar and G. tholloni to also be sister taxa. They also found that these two clades diverged during the middle of the Oligocene (around 27 million years ago).
That’s a deep divergence and this, combined with anatomical differences, led them to suggest resurrection of the name Xenurophis (originally applied to G. caesar), albeit as a subgenus within Grayia.
Chaney et al. (2024) also found that Grayia included a hitherto overlooked distinct lineage that appeared to be cryptic species, and named G. obscura for a population from the Upper and Middle reaches of the Congo River and nearby.
Spawls et al. (2018, p. 536) made reference to “one undescribed species” known from Cameroon, though I don’t know of its current status.
Incidentally, the common name ‘Caesar’s African water snake’ for G. caesar is fairly inappropriate since it seems that Günther named this snake in possible recognition of its magnificent, regal form (Beolens et al. 2011) (‘caesar’ being a name used for Imperial things thanks to its original association with the Roman emperor). A more accurate vernacular name would thus be ‘Magnificent African water snake’ or ‘Regal African water snake’ or such.
Known to Loumbou, Massango, Pounou and Nzebi people there as the dibomina (other local names exist too), the snake is regarded as non-venomous and as the “grandfather of all the other snakes”. It’s widely eaten and regarded as a valued food item.
Being aquatic, the snakes are most often captured in fishing nets but they’re also caught by hand in submerged burrows otherwise being investigated for catfish. In some places, G. ornata is also used to provide medical assistance to women in labour: the snake’s dried head is kept in a safe location, and water poured through it is drunk by the mother.
Pauwels et al. (2002) explained that this connects the snake’s use of water as a refuge with the belief that the baby’s head will emerge faster than otherwise.
Until recently, I’d wrongly thought that these were animals of the Congo region alone. But they’re actually hugely widespread across continental Africa, with a range extending from Niger in the north to Angola in the south-west, and Kenya and Tanzania in the east.
A common complaint made about animals of all sorts is that it can be really hard, if not impossible, to find what local people - not explorers, naturalists or scientists from foreign, typically European, lands - know or think about them. The good news for Grayia is that a published study dedicated to local knowledge exists, albeit pertaining only to the Chaillu Massif of southern Gabon, and only to the Ornate African water snake G. ornata (Pauwels et al. 2002).
One of the first studies to analyse caenophidian snake phylogeny using genetics - they used one nuclear and three mitochondrial genes - was published by Vidal & Hedges (2002).
Here are some (but not all) of the snake-themed books I checked while preparing this article.
Snakes (Serpentes) are one of the most feared reptiles in the world, with an estimated 200 million to 1 billion people worldwide having ophidiophobia, which is the fear of snakes. However, most snakes are not aggressive, typically retreating rather than attacking when confronted. Snakes play a vital role in their local ecosystems; they keep the populations of their prey species at sustainable numbers and, in turn, are sometimes prey for larger animals.
Certain types of African snakes, like pythons and some vipers can see their prey, even if the best eyes cannot see them. They can do this because they can sense their prey - they can ‘see’ their heat.
Birds nest in spring and this is when you usually see the common egg-eater African snakes. For the rest of the year it is barely seen - despite being a common species of snake. This nonvenomous snake is not a threat to humans.
Rinkals playing dead,. When you see a snake looking like it is dead, please do not go up to it and poke it to check if it is actually dead. Some snakes make themselves look as if they are dead, they feign death, so that a predator loses interest and leaves it alone. Some of those snakes are venomous that do this - like the Rinkals snake.
African Snakes have powerful muscles and they cover ribs, which the snake uses to lean on to ‘walk’. What is actually making them move are waves of pulling and releasing powerful muscles.
The best way to avoid snake bites? Unfortunately, we cannot swing a magic wand and expect a straight forward answer to that, just know that there are about 600 species of African snakes in Africa, and out of all of them, only a small amount are venomous - most of the snakes in Africa are harmless to humans.
The African or brown house snake, harmless to humans and a constrictor.
Snakebites in Africa are a real problem, especially to people living in rural areas, campers, safari walkers and so on.
Please realise there is no effective way one can chase away or stop snakes. There are people out there selling ‘potions’ and other stuff to people who believe they will work.
Please listen carefully. Those people are cheating and lying to you - there is nothing on this earth that can do that. Burning tyres near your home, or spreading used engine oil does not chase snakes away and prevent them getting near your home, or dwelling.
Venomous Snakes of Africa
Africa is home to some of the world's most venomous snakes, posing a significant threat to both humans and animals. These snakes possess potent toxins that can cause a range of effects, from localized pain and swelling to paralysis and death. Some of the most notable venomous snakes in Africa include:
- Black Mamba (Dendroaspis polylepis): Africa’s largest venomous snake, renowned for its speed, aggression, and highly toxic venom.
The Black Mamba (Dendroaspis polylepis) is Africa's largest venomous snake, reaching an average 2.5 m in length (8 feet) but can get as long as 4.5 m (14 feet).It's extremely aggressive, and will not hesitate to strike, very fast and agile, it can reach speeds of up to 12mph (20 km/h).
- Mozambique Spitting Cobra (Naja mossambica): A common cobra species in tropical and subtropical Africa, known for its ability to spit venom with great accuracy.
The Mozambique Spitting Cobra (Naja mossambica) is probably the most common cobra found in tropical and subtropical Africa. It is considered one of the most dangerous African venomous snakes, overshadowed only by the black mamba. As the name indicates, the Mozambique Spitting Cobra can "spit" it's venom. However "spraying" is probably a more accurate definition. The snake can spit/spray it's neurotoxic venom with great accuracy at distances up to 3 m long. Their bite can cause severe tissue damage, if the venom hits the eyes it will cause impaired vision or even blindness. When molested, this snake can also elevate as much as two-thirds of its body.
- Puff Adder (Bitis arietans): Responsible for more human fatalities than any other snake in Africa, due to its widespread distribution and reliance on camouflage.
The Puff Adder (Bitis arietans) is responsible for more human fatalities than any other snake species in Africa. The species accounts for some 60% of all snakebites in the continent. It's the most common and widespread snake species on the African continent and inhabits the majority of regions, except for desertic regions and rainforests. Since the species relies on camouflage to hide and will lie still when approached, people tend to step on them and get bitten. They have very long fangs, 12 to 18 mm long, and an average body length of around 40 inches (1 m). The Puff Adder moves in a similar fashion to the way caterpillars move. They are good swimmers and climbers.
- Gaboon Viper (Bitis gabonica): An ambush predator with a high venom yield and the longest fangs of any snake species.
The Gaboon Viper (Bitis gabonica) blends perfectly in the leaf cover and surrounding vegetation making it the ultimate ambush predator. It ambushes its prey, large birds, and some mammals, by standing still and attacking by surprise. They are very heavy-bodied snakes that can weigh up to 10 kg and can grow to over 2 m in length. With a large triangular shaped head, the species develops two nostril horns with age.
- Egyptian Cobra (Naja haje): A widespread cobra species known for its potent venom.
Despite what its common name would suggest, Egypt is not the only habitat for the Egyptian Cobra (Naja haje). The species is commonly found in Egypt, but in fact is the most widespread of the African cobras. Their average size is between 1.5 to 2 m, though some specimens can exceed 2.5 m (8 feet) in length. The Egyptian Cobra venom is considered the 3rd most toxic venom of any cobra species, just after the Northern Philippine Cobra and Cape Cobra.
- Saw-Scaled Viper (Echis carinatus): Found north of the African Equator, the Saw-Scaled Vipers (Echis carinatus) are small yet viciously aggressive and easily excitable temperament snakes. The average adult vipers reach a length of around 20 to 30 inches.
There are 5 subspecies currently recognized. It's the smallest member of the Big Four Indian snakes which are responsible for the most snakebites and deaths in India. The species gets its name from the "sizzling" sound it makes as it rubs its scales, and serves as a warning.
- Boomslang (Dispholidus typus): A tree-dwelling snake with highly toxic venom.
The Boomslang (Dispholidus typus) is found in sub-Saharan Africa and is considered the most venomous rear-fanged snake in the world. The name "Boomslang" comes from the Afrikaans word "tree snake", it's a "tree-dwelling" snake species. Much like the Gaboon Viper, the Boomslang fangs are very long, and it can open its mouth at a full 180 degrees to bite.
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