What kills or eats snakes?

Text Pat McKrill Photographs Pat McKrill, various

Preamble amble

On the face of it, this was anything but a challenging assignment – all that was needed was an alphabetical list of just about everything on this earth that has a mouth. But that would have used up a lot more than the 2000 words I had to play with, then I had to consider the educational purpose of the article, including the rider; that some form of photographic evidence might be required to back up my observations and contentions – snake killing is not something we would normally trouble to record. Perhaps I was wrong about the lack of a challenge.

Snakes are not fuzzy and warm, so they get killed with impunity by humans, based on the almost universally held belief that they’re simply evil and dangerous. Added to the predilection that some of our eastern cousins who make up a significant portion of the world’s population have for the skin and body parts of just about every other living creature on this planet, including the snake, we can also factor in that when man’s not deliberately killing snakes for whatever reason, he’s also doing it by remote control, through his unfettered habitat destruction that impacts negatively upon our environment.

Asian snake market (Photo: Getty images)

Road-kill, accidental or not, also makes a notable contribution to the stats on the human-driven killing of snakes. With this brief overview, we can perhaps excuse snakes for producing more than one offspring at a time!

Despite his not unremarkable contribution, we can’t really say that man is the main culprit in this carnage. The animal kingdom itself is not exactly the idyllic paradise we mentally conjure up every time a butterfly flutters by, or a lioness with cubs kneels down to drink at the waterhole. Nosiree, there’s some serious stuff going on where my favourite animal plies its trade – and I’m going to try and give you some idea of what the poor guy is up against.

Those who have been following the trend in the previous articles (see here and here), will know that we’ve concentrated on some of the commonest snakes that are found in the Highway area, however for the purposes of this article, I’ll touch on what kills snakes generally, world-wide. Although some of the predators and their prey I’ve mentioned apply to the highway region, the premise remains the same wherever we find snakes – most other animals kill snakes. There’s a frustrating aspect to this whole thing, as there’s a dearth of specific research material on the subject, and I’m not aware of any programmes specifically dedicated to the study of what kills snakes. Much of what I write in the article comes either from personal observations or has been taken from reliable sources – few and far between. American herpetologist Chris Mattison writes in his book The Encyclopaedia of Snakes, that in addition to the fact that although there are many things that kill snakes year round, snakes in hibernation are particularly vulnerable to predation. This makes sense I guess, but here in KZN, our winter is not as bone-chilling as it is in some of our other provinces, so perhaps our guys are, somewhat incongruously, better off.

Should you feel tempted to join the research party, grab a note pad, emergency snake-bite kit, bino’s and a camera, but I’d urge you to remember that you’re a note-taking spectator, and although you might feel sorry for the toad you see hopping and dragging an attendant night adder across the veld as the snake hangs unyieldingly onto its leg, or conversely, a metre long Mozambique spitting cobra fighting for its life in the grip of a raptor on the ground in front of you, please, no matter your feelings for the victim, don’t try to separate the predator from its meal – apart from standing the chance of becoming an unsuspecting victim yourself, that folks, is how nature works. Let it work.

Who wants to be an egg?

I’ll begin my foray by looking at the egg stage and working onwards from there. Although we have a few viviparous (live-bearing) snakes in the area, at this point we’ll ignore them, and concentrate on the oviparous (egg laying) species which, apart from the Rock Python which is known to stay with its eggs until they hatch, simply lay their eggs in a hole, hollow tree, compost pit etc. – wherever there’s reasonable protection and an acceptable temperature range for the nurturing process – and move on.

Brown house snakes hatching (Photo: Nick Evans)

Unguarded eggs would seem to me to be a natural target for predators, and apart from any number of animals, leguaan, rodents etc. that might eat the snakes’ soft-shelled eggs, they would also be prone to insect parasitism, whereby the insect’s eggs are injected into or laid onto the outer skin of the egg. I’ve twice found clutches of snake eggs in the wild that have been targeted by a small fly (spp. unknown to me) and that have subsequently become maggot-infested. Perhaps our snakes can chemically protect their eggs, because it’s always struck me as strange, that they often leave the eggs technically exposed, rather than bury them or put stuff on top of them to hide them, as does the Indian King cobra.

Being popular is not always Kool!

The next chapter in the story would be the predation upon the freshly emerged youngsters, and at this point we can include the progeny of the viviparous (puff adders and slug eaters to name two of the common Highway species) amongst the potential targets. A mass hatching of anything in the wild would attract attention; a good example would be the clouds of freshly emerged flying ants fluttering upwards from the ground after a summer afternoon downpour, that attract all manner of opportunistic predators, thus, a bunch of baby snakes – anything from half a dozen to 50 plus – emerging from a hole in the ground or from a gravid female lying under cover somewhere, would similarly attract attention. As an interesting aside to the subject, although many snakes eat other snakes, there is an erroneous belief that puff adders swallow their young when they perceive them to be in danger, and this belief possibly comes from observers having seen hatchlings emerging from a freshly killed, gravid female puff adder. QED?

The Mozambique cobra is very partial to snake meat

The Cape File snake also eats snakes, and is highly venom resistant

Possibly a competitive feeding accident but this Slug eater swallowed a relative which re-emerged, alive! (Photo: Mansfield family)

To list all the perpetrators that would potentially kill hatching snakes would require more space, so I’ll stick to the commonly known culprits. To me, the most frustrating aspect of these once-in-my-lifetime happenings, is that I’ve never been prepared with my trusty camera at the ready, to record the events when they happened (got a good phone camera now, so that might change). I’ve seen guttural toads (the amphibious equivalent of the village goat when it comes to its rather catholic food preferences) eat recently hatched snakes, and once, whilst releasing some home-incubated brown house snakes into the wild, to my horror, I watched a large ground beetle emerge, clutch one of the hapless juveniles in its mandibles, and drag it back down into its hiding place, certainly not for a friendly chat back at the beetle ranch. There are numerous spider species that are known to eat snakes, particularly the sub-adults and the freshly hatched. By saying ‘eat’ I’m referring to the way in which spiders consume their trapped food, using their venom to turn it into a ‘smoothie’ that can be consumed in a semi-liquid form. I’ve seen the desiccated bodies of snakes in the web of the brown button spider and in the mandibles of a fishing spider that had killed a juvenile Herald that it had caught alongside a farm dam. Some orb-web spiders are known to catch and eat smaller snakes that accidentally wander into the web area.

Guttural toad

Sweet revenge of the Night Adder eating a guttural toad

Night adders being released

Herald snakes hatching

Brown button spider and her kids

… and it doesn’t get any better.

The final stage in this trilogy takes note of some of the known and recorded instances of predation upon snakes from sub-adult onwards, by some of the more commonly encountered vertebrates in the wild, say from for example, the ubiquitous cat family (from the home-raised tabby to the not so cuddly lion). There’s no question that most animals have a high degree of memorised or imprinted understanding of the animal they’re hunting, and there has to be a form of communication between the adults and their progeny from birth, if not before, around the subject of potentially dangerous animals, passing on the do’s and the don’ts, and we needn’t look too far from home before we see evidence of this. Why do dogs – even puppies – bark at, and often attack snakes? Do they have a manual that lists the so-called bad things? What about the cats that stalk them gingerly, but once they’ve captured one, venomous or not, gratuitously torture it for hours, treating it as a harmless toy, before abandoning it – usually under your bed? I’m sure it happens, but I cannot recall ever having been told of a cat having been killed by a snake. Who teaches the birds to form those multi-species conglomerates of hecklers, who ignore their past interspecies spats, in order to join the frenzied warning choruses around a snake – always just out of striking range?

Boomslang being mugged by assorted birds (Photo: Carol Robertson)

These same animals must undoubtedly pass their experiential knowledge on to their youngsters, in addition to that which we call instinct, which already exists. I’d love to be able to listen to adult birds telling their kids how to avoid the lightning strike of a hungry boomslang.

As we know, creatures in the wild can’t order take-aways every time they want a meal, so many of them will kill snakes, and not necessarily in a pre-planned attack. Maybe we should also consider other reasons;

  • they’re simply hungry and they’ve acquired a taste having eaten snakes previously
  • they see one at an opportune moment and they’ll try anything once
  • they feel threatened, and attack

A couple of opportunistic Jackal sharing a meal (Photo: Nadine Loubser)

As many of them are foragers, the likes of the mongoose, vervet monkey, jackal etc. all of which are omnivores although with a preference for insects, will certainly have the occasional snake on its eclectic menu. Although the mongoose is believed to be a snake killer of note, much of this belief can probably be laid at the door of Rudyard Kipling who planted the idea into our heads through his captivating Jungle books, immortalising the adventures of the home-raised mongoose, Rikki Tikki Tavi. They certainly do kill snakes, in addition to the other food they consume, but apart from the other species that inhabit the highway region, probably the most common mongoose in the area would be the banded mongoose, which according to Richard Estes (The behaviour guide to African mammals), has vertebrates, including snakes, forming only about 12% of its diet. This average applies to most of the mongoose species I looked into.

With acknowledgement to my twitcher friends, there’s no question that birds rate high up on the list of snake killers.

Hammerkop will eat any bite-sized snake at the water’s edge

Herons generally will keep the grass – and snakes on their toes

The venerable Ground Hornbill is well-known for his penchant for puff adder (Photo: Steph Vermeulen)

In the Highway area alone, although Snake eagles are best-known for the meal preference that gives them their name, we can’t discount numerous other raptors, along with the Secretary birds, Hadedas, Shrikes, Rollers, Starlings etc. who, like a host of other birds when they’re hungry, are sometimes anything but the lovable budgies we make them out to be, in fact, they’re clinical assassins.

As Gerrie might say, “based on the above synopsis m’lud, at this point I think I can confidently rest my case, by repeating my opening remarks in answer to the question ‘What kills or eats snakes?’, when I say, “Just about everything on this earth that has a mouth”.

However, it’s not all bad, as long as the balance remains, but it’s entirely up to us humans as to which way we go. It’s the only world we’ve got.

Author photo: Pat McKrill

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.