Have you seen a snake in your garden recently? We are fortunate to have about 120 species of snakes in South Africa. As part of a citizen science initiative, the National Museum’s Animal and Plant Systematics Department – Herpetology Division is managing a Facebook group called Free State Reptiles and Amphibians (including adjacent areas and Lesotho) which seeks to gather photographic and videographic records of all reptiles and amphibians found in this region. These records have resulted in re-examinations of the distribution of the Rinkhals Hemachatus haemachatus (Bates & Stobie, 2022), Puff Adder and Cape Cobra (in preparation), amongst others. We have been particularly interested in our Bloemfontein records as a way to investigate finer-scale distribution patterns, and we are now gaining a better understanding about which species occur in the various city suburbs and small holdings.
We have currently photographically recorded 18 species of snakes that occur naturally in Bloemfontein, although a few other species are also expected in this area but are rare or live underground. Records of four exotic snake species have been obtained, together with an additional two South African species that occur in other provinces but have apparently been translocated to Bloemfontein. Across the wider Free State region we have accumulated records for 36 of the 42 snake species expected to be found naturally in this area.
There is a common misconception that most, if not all, snakes are deadly. In reality, very few snakes are actually dangerous, although all snakes should be treated with respect, especially if you are unsure about their identity. Even venomous species are not necessarily ‘dangerous’ as they usually avoid humans rather than actively pursue and bite them. Of the 18 species we have recorded thus far in Bloemfontein, only three are classified as highly venomous, one as venomous, six as venomous but not dangerous, and eight as non-venomous. The four medically-significant species that we have recorded in and around the city are the Puff Adder (Bitis arietans), Cape Cobra (Naja nivea), Rinkhals (Hemachatus haemachatus) and Highveld Garter Snake (Elapsoidea sundevallii media).
An exciting reason for using Bloemfontein as a setting to examine fine-scale records is that the distribution ranges of two medically-significant species, the Cape Cobra and the Rinkhals, appear to be located mostly on either side of the city. There have been some sightings of both species on the ‘wrong’ side of the city, but in general Cape Cobras are much more likely to occur on the western side of Bloemfontein, while Rinkhals seem to occur almost exclusively in the east. We will be investigating the reasons for this apparent biogeographical structuring.
The three species of snake that are most commonly reported in Bloemfontein may not actually be the most abundant species in the city. This is perhaps because people tend to mostly post photos of unusual or venomous species, rather than common ones. Despite this, due to the large number of records received for these three species, it does seem that they are relatively abundant in the city. We will now expand on the three most commonly reported species of snakes in Bloemfontein – the Puff Adder, Cape Cobra and Brown House Snake.
The Puff Adder (Bitis arietans) is the species most commonly reported on our Facebook group. These snakes are relatively large and stout, usually growing to about one meter in length. They typically have pale, dark-edged, backwards-pointing chevrons on the back, although we recently described a specimen from Bloemfontein that lacks these markings (see Bates, Stobie & Hastings, 2023). Unfortunately this species is involved in the largest number of serious snake bite incidents in the country (Alexander & Marais, 2007) due to a combination of its abundance, cryptic colouration, tendency to not move away when approached, and because it lies on or near paths while waiting to ambush prey. It expels air with a loud, intimidating sound if threatened, which is probably how it got its name. Puff adders have a cytotoxic venom that destroys cells and soft tissues in the body. As a result, they are widely persecuted, even though they fulfil a very important role in the food web by curbing rodent populations.
The second most commonly reported species is the Cape Cobra (Naja nivea). Despite the name, this species is found quite widely across western South Africa, Namibia and Botswana. In the Free State it is often referred to as ‘geelslang’. These are quite large snakes, attaining about 2 m in length. They occur in a range of colours, though yellow is the most common. The tail tip is usually black or dark brown. Juveniles usually have a dark band across the front of the neck. This species is responsible for the majority of snake bite deaths in South Africa, although, as with most species of snakes, the Cape Cobra will rather flee than fight. It has strong neurotoxic venom that acts on the nervous system (including the brain) and affects the respiratory system.
The next most commonly reported species is the Brown House Snake (Boaedon capensis). These are non-venomous constrictors with several sharp teeth but no venom fangs. They can bite and draw blood, but should not be regarded as ‘dangerous’. Brown House Snakes in the Free State exceptionally grow to about one meter in length, although in KwaZulu-Natal they can grow up to 1.4 meters (see Alexander & Marais, 2007). This snake is generally a reddish brown colour, although it may be a darker brown. The head usually bears a pair of cream stripes on each side, running from the nose to above the eye and continuing to the back of the head. When the head is viewed from above, the pale stripes form a ‘V’. In some specimens from KwaZulu-Natal this stripe extends all the way down the body. This is probably the most common snake species in Bloemfontein and is easily recognised by its distinctive colour pattern. It may be under-represented on the Facebook group because it is so common and not as ’exciting’ as the venomous species. Brown House Snakes are often found in urban areas and around houses, where they search for rodents and lizards, and occasionally even birds and bats.
The Herpetology Division has been privileged to work with a number of talented and dedicated local snake relocators. These are often experts who have received training to remove snakes, responsibly, from homes or businesses and release them back into the wild. If you find a snake in your home, calling a snake relocator to remove it is perhaps your best port of call. Trying to remove it yourself can be dangerous! Snakes are an important part of the ecosystem and some species, such as Brown House Snakes and Mole Snakes, play an important part in curbing local rodent populations. A small callout fee for the service that the snake relocator provides is generally considered appropriate, especially as fuel is not cheap these days! If you are in need of such services, download the African Snakebite Institute app and reach out to someone in your area.
If you have any photos of snakes or other reptiles or amphibians that you have encountered in the Free State and Lesotho regions, please do consider posting to our citizen science Facebook group Free State Reptiles and Amphibians (including adjacent areas and Lesotho). These records allow us to accurately map the current distributions of our species and investigate trends in their occurrence over time.
REFERENCES
Alexander, G. & Marais, J. (2007). A Guide to the Reptiles of Southern Africa. Penguin Random House South Africa.
Bates, M.F., Branch, W.R., Bauer, A.M., Burger, M., Marais, J., Alexander, G.J., & de Villiers, M. (eds). (2014). Atlas and Red List of the Reptiles of South Africa, Lesotho and Swaziland. Suricata 1. South African National Biodiversity Institute.
Bates, M.F. & Stobie, C.S. (2022). Current-day distribution of the rinkhals (Hemachatus haemachatus) in central South Africa and Lesotho: An evaluation based mainly on photographic and videographic records from social media. African Journal of Herpetology, 71(1), 94-100. https://doi.org/10.1080/21564574.2021.1998237
Bates, M.F., Stobie, C.S. & Hastings, J. (2023). An unusual ‘speckled’ puff adder Bitis arietans (Reptilia: Squamata) from central South Africa. African Journal of Ecology (in press.).
Uetz, P. (editor), The Reptile Database, http://www.reptile-database.org, accessed 9 February 2023.
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