How long do some of our (Kloof) snake species live?

Or, as interpreted by me, “How long is a piece of string?” Those of you who are concentrating, might have considered that snakes and most other noonoos don’t hang around to have their life histories studied. To achieve this, if we must, we’ll need to find a clever way to monitor every second of life, from egg to grave, so until then…..

Herald hatchlings.

A freshly hatched Night adder…..

Studying snakes, is not as simple as it might sound, there are many curve-balls along the way. For instance, specific species length is not necessarily age related. Older snakes don’t get wrinkly skin and droopy eyelids. A Brown House snake Lamprophis capensis, if born in the KZN veld, over a given period of time, will grow quicker and initially be proportionately larger, than a same species snake born on the same day, in some other areas of the country.

Brown House snake…

The reason? We have longer, warmer summers and shorter, less frigid winters to contend with, and KZN snakes can access food for longer periods than can their northern cousins. Carbon dating fossilised snake bones is possible, but this doesn’t tell us how old the snake was.

The teeth might be fossilised….

In order to answer the question, I’d need to be an Enviroboffin. An Enviroboffin would be an environmentalist who has dedicated themself to the study of a specific branch of the environmental sciences, take your pick, to the point where they know just about everything there is to know about their subject, ALMOST right up to the time when the next ‘what about?’ question gets asked.

I think it went in here.

Using those parameters, and because of what we’re discovering every day, one would imagine that the world has plenty of these people, and I’m not referring to married couples or teenagers here. But unfortunately, only until fairly recently, the last 30 years or so, has the grossly unreasonably feared and senselessly hated snake become worthy of any deeper form of respect and research than before. Only now are we beginning to understand something of how they work and how they’ve managed to evolve and survive over millions of years. There’s lots of catching up to do.

I have the greatest respect for those friends of mine who study plants in the wild, but envy the fact that for many of them, their specific study models are unlikely to uproot themselves during the research project and head elsewhere because they don’t like the weather.

A Baobab going nowhere fast.

But when we look at the faunal (geneticist) field, it’s a different matter, and there are few study models in the wild that don’t suddenly take off to wherever, never to be seen again. Some might be a bit easier to track; take some of our insects for example. The range of insects available for research projects boggles the mind, and if one were to study a particular species of fly pest for pest control purposes, you’d need to know all there was to know about the fly if you were to be able to design a specific control mechanism or product for it. Insects with localised distribution patterns and above ground lifestyles might be a lot easier to study than migratory insects such as some of our butterflies, but whatever the subject, if it can get up and move on, it presents problems for the researcher.

Yellow Billed Kites are back for the summer.

As with any creature in the wild, the monitoring process would start from the hatching, right through to the last gasp. In the case of a captive subject, this would be a doddle, but in the real world, there are different rules. With regard to snakes in the wild, there are variables in terms of what would affect their natural lifespan. I’ve chosen to ponder some of those factors in the life of some commonly resident (not necessarily commonly seen) species in the Kloof Conservancy area, but forgive me for repeating myself in terms of some of my previous articles, and as always, I’d welcome constructive input.

I’ve gathered some relevant bits and pieces that might help us to put together some idea of what they have to deal with and adapt to in order to live full lives. Wherever I put in an estimated life expectancy, this will more than likely be based upon knowledge gained from captive breeding records. There are some indicators in the basic knowledge we have on snakes, that might lead us to a better understanding of these creatures, down to their vulnerability in the wild. For example, why would an 800 mm live-bearing Puff adder Bitis arietans, want to produce, anything from 30 up to in excess of 40 young in one birthing, whereas an egg-laying 1 metre long fossorial (underground) Natal Black snake Microlaps microlepidotus, only lays about 3 to 8 eggs? Is one species less vulnerable than the other?

Puff adder. Anything but lazy.

Natal Black. A fossorial garden guardian.

Photo: Di White

How about our Natal rock python Python natalensis, some of which have been recorded as laying over 80 eggs at a sitting, whereas our Brown house snake and the Herald snake, Crotaphopleltis hotamboeia only lay up to about 12 eggs at a time. The length or proportions of the creatures seems to bear no relevance to the numbers of progeny produced, which blows any so-called sound reasoning out of the equation. Are the big breeders producing extra numbers to make up for the inevitability of predation, food shortages or habitat destruction.

If so, what about those who produce much smaller numbers? Perhaps they’re more confident for some reason, of a greater chance of survival for their kids. More secure living conditions? Better defence mechanisms, more frequent birthing over a given period? Less specialised food preferences? So many questions, but I am quite sure that the disparities are species specific and deliberate, I’d just love to know why. In the following examples of snakes in the wild that I’ve tried to keep tabs on over the years, I’ve kept it as ‘wild’ as possible, trying to exclude any man made influences (an almost futile exercise) that might have changed the behaviour of the snake.

Puff adder (Bitis arietans)

Life span, based upon my understanding of its ability to hide and camouflage itself in the wild, probably live into the 20 to 30 years bracket. Our best-known ambush feeder is also not too shabby it seems as a forager, based on what I’ve seen on social media posts showing different puff adders carrying out some adventurous tree climbing and carcase rummaging in their search of sustenance (or was it perhaps mere curiosity?) This snake is usually found living close to the surface of the soil where it hunts, in hiding places that don’t require too much climbing to enter, sometimes under rock piles or ledges, abandoned animal burrows or hollow logs – some that might have contained a previously resident meal.

In winter, they might move into areas that have an ambient temperature in the mid to low 20’s deg C. Like many of our snakes in the warmer KZN climate, they do not hibernate in the conventional sense, and will make use of the morning sun for health reasons we assume, not necessarily always to aid digestion. To get a fix on lifestyle and age would be extremely difficult, unless the hatchling is photographed or microchipped on day one, and thereafter followed. I’d guess that the only way to ascertain that it was the same snake, would be to record the ‘fingerprint’ that any patterned or damaged snake would have throughout its lifetime. These identification methods would need to apply, no matter the species.

Puff adder with its exclusive markings.

Puff adder. Spot the differences.

As with all snakes, hatchlings are unlikely to be nurtured by the parents for any particular length of time, and they have to seek greener pastures and new food sources elsewhere almost immediately, before they unwittingly end up on the buffet table frequented by nearby visitors, friends and relatives, all in search of new, tasty morsels.

Boomslang (Dispholidus typus)

An arboreal forager that remains fairly loyal to its name. Still very much a tree snake, but now being seen in lesser treed habitats than before in the areas where man has encroached and changed its once perfectly suited habitat. Due to their exposure to other predators in their habitat – particularly raptors – I doubt that we’d get too many old teenagers in the wild. They can grow to in excess of 2 metres.

Boomslang feed mainly on birds – adults, eggs and nestlings – chameleons, tree lizards and frogs. Serious indigenous gardeners with well-established gardens, should note the possibility of more frequent visits or even habituation that will ensue, based on the consequential provision of a wider range of food sources.

The female lays up to about 12 eggs, and these can be laid in hollow trees or abandoned woodpecker and barbet type holes in trees where temperatures are typically in the mid 20-30 deg.c range, year round. From mating to hatching could take anything up to 8 months.

300 mm long juvenile Boomslang.

Vine snake aka Twig snake, or Bird snake (Thelotornis capensis mossambicanus)

Similar habitat, location and food sources to those of the boomslang, but these snakes seldom exceed 1.3 metres in length. In terms of longevity, I’d put them in the same class as the Boomslang, for the same reasons as given above.

Life saving camouflage. The Vine snake. Wide hunting range.

Southern African Python aka Rock Python (Python natalensis)

There are still 5 metre-plus snakes around, but because of their value in the muti and ‘pet’ trade, there won’t be too many oldies hanging about. They’re ambush feeders rather than foragers, who will typically remain localised once mature – hauling 30 kgs plus of body weight from one part of the veld to a distant new home elsewhere because of a food shortage is not an option. They’ll live in abandoned animal burrows, rock crevices or hollow trees, often close to water, unlikely to venture further once they’ve matured. I’ve heard of some resident and respected pythons, living unharmed in some rural areas, and I’ve also heard of pythons living up to 50 years in the wild, probably well known to older local residents who’ve lived nearby, and recognise them. There are reports of specimens having lived up to 30 years in captivity.

Python. Perhaps our longest living snake.

Natal Black snake (Marcrelaps microlepidotus)

A common local resident that is being seen more frequently by gardeners (and hopefully not being killed). The fact that it’s fossorial means that it would be extremely difficult to track its life history, plus the fact that their dietary preferences are not that specific so we can’t really determine their ‘drawcard’. Thankfully there are those who have finally come to terms with the “every black snake is a Mamba” belief, and if we can continue to spread the message about the value of snakes in our ecosystem, we might see more. A docile but venomous snake that probably lives into the late teens.

Night adder (Causus rhombeatus), and Herald snake (Crotaphopeltis hotamboeia)

Our best known toad eaters, nomadic to some extent, and more than happy to relocate to an abandoned hole in the ground or hollow tree (possibly unintentionally vacated by the ex-owner who became a meal). I cannot imagine either of these guys living beyond the early teens in the wild. The competition amongst the toad eaters is hectic, and any of the smaller snakes that fit into this category merely seem to get added to the diet of their bigger competitors, the Mozambique Cobras and the File snakes, who are also found within the Kloof conservancy boundaries.

Night Adder

Herald telling you…

The Cape File snake. Now you see me, now you don’t.

Any clever ideas on how one could accurately track the life of a snake from birth to grave, let me know, we’ll go into business. In my reading research into this amazing subject, I’ve been as far back as FitzSimons in 1912, Ionides in the 50s and 60s, then Broadley, Visser, Isemonger, Branch, Marais, Alexander and Spawls et.al. Enviroboffins every one. Thank you all.

About the author

Pat was born in the UK, educated and brought up in Rhodesia/Zimbabwe, and came to South Africa in 1983. He developed an early interest in the study of the behavioural aspects of insects and animals, rather than the deeper scientific side, and he’s worked with snakes for most of his life. Pat conducts educational walks and talks throughout SA and into neighbouring countries where snakes are grossly misunderstood and needlessly killed. He writes articles for a number of publications, and has written the book ‘Getting to Know the Neighbours’, which is all about understanding snake behaviour and is aimed at teaching others how to come to terms with them.

Pat can be contacted at: herpet@snakecountrycc.co.za.