GARBAGE GUTS - AUSTRALIAN TIGER SNAKES

Raymond Hoser

Originally published in Reptiles (USA), March 2007, 15(3):48-60 (with photos).

INTRODUCTION

Tiger Snakes, Notechis scutatus are the most common large elapid in many parts of Australia.  This includes around Melbourne, Australia's second largest city, where for some years I was the only "snake catcher" in the city's phone book and hence I got daily calls to catch these snakes in people's gardens.

In the wild state, they are typically about a metre long as adults, a greyish brown colour with reasonably distinct bands and almost without exception will try to kill anyone who attempts to catch them.

Because they are so aggressive when caught and because they are so common, they are not in the list of Australia's favorite captive snakes for most local herpers.

However, for those people who get past the initial aggressive behavior, they soon find themselves with one of the nicest and trouble-free pets available.

THE SNAKE ITSELF

Tiger Snakes are deadly.

Until recent times, they accounted for most of the snakebite deaths in Australia.

This was due to the fact that they are deadly venomous, won't hesitate to bite when cornered and are very common around the populated cities of Melbourne, Adelaide, Sydney, Hobart, Perth and Canberra.

They are a generalized elapid, but of slightly more thick-set build than other common species in Australia like the Red-bellied Black Snake (Pseudechis porphyriacus) or Brown Snake (Pseudonaja spp.).

Tiger snakes of various forms are found in the colder and wetter parts of southern Australia including most of Victoria, much of NSW, far south-east Queensland, Tasmania, south-east South Australia and south-west Western Australia.

The nominate form is Notechis scutatus from NSW, Victoria and nearby.

Other races are sometimes assigned to the species "ater" or black Tiger Snake, and races from several islands or outlying areas are assigned subspecies names such as "occidentalis" (in WA), "serventyi" in Bass Strait, and so on.

All are evidently closely related and based on DNA studies it has been proposed that all forms should be assigned to either one or two species only.

The plasticity of Tiger Snakes in terms of regional variations and adaptations to local conditions is well known.

Even around Melbourne, where all Tiger Snakes are obviously of the species scutatus, there is a huge variation, not just within a location, but also between them.

Specimens from the coolest area, the Dandenong Ranges are nearly black, while those from the warmest areas such as Keilor are substantially lighter and with much more distinct cross-bands.

In some areas, such as Melton, the snakes are generally brownish in base colour, while those from Portsea on the Mornington Peninsula are a silvery grey colour and with relatively indistinct bands.  Another suburb, Langwarrin has snakes with blue and grey bands.

All this from within 100 km of the Melbourne CBD!

Size?

This varies as well.

The average for a non-growing adult is about a metre.

Anything longer is big.

Anything over 1.5 metres is a monster that should be in a Museum!

Books are often quoting enormous sizes and lengths for these snakes, but when you finally get to see the living things, the size seems to shrink somewhat.

But due to the thick-set build, they are still a big animal.

Males get bigger than females.

A female over 120 cm (4 foot) is as rare as a male over 150 cm (five foot) (total length).

Most Tiger snakes have the recognizable cross bands (hence the name Tiger Snake), but some don't.

This may be the case even in a single litter of snakes!

The genetics of colour in these snakes is more complicated than just one or two genes and so far no one's come close to working anything out with them.

FINDING TIGER SNAKES IN THE WILD

That's something few people in Australia need to do.

Here there is a reasonable number in captivity and because they are as horny as Death Adders (Acanthophis) they breed like er, well Tiger Snakes.

The small number of people here who have Tiger Snakes, tend to breed them if they throw them together.

The snakes won't hesitate to mount one another during live snake shows and even these unions in front of hundreds of onlookers have produced lots of live young.

These snakes produce about 20-30 live young at a time (under 20 is fairly uncommon) and so every year we have a situation of Tiger Snake owners trying hard to offload unwanted babies.

Put simply, it's often hard to give them away!

The main reason for the lack of interest is that the snakes are 'deadly'.

While talking numbers of young, Tiger Snakes are the most fecund of Australian live-bearing snakes, with the literature quoting cases of over 100 young born at once, although frankly I think that figure is an exaggeration by someone wanting to claim a record.

Hence few people in Australia actually go looking for Tiger Snakes!

As to where I go to find my Tiger Snakes, well, I don't go out on a herping trip to look for them ever!

The phone rings at my Melbourne home and I am asked to catch a snake in someone's yard.

Most of the time it's a Tiger Snake.

In November/December, it's common to go for weeks on end getting a couple a day.

By law these are released in suitable uninhabited areas, but sometimes I may accumulate some for a few days that sit in boxes before they get taken away.

While all are very aggressive when I catch them, most settle down within days and become quite easy to handle and move around.

By this I mean, that within days they are happy to be hook handled and moved about and not get agitated.  Put simply, these snakes bite from fear and this rapidly evaporates.

This gives an idea of what to expect if you keep them.

As for where Tiger Snakes are found, well, for the tourists who may want to look, I'll tell you.

They live in all kinds of habitat, but they prefer so-called "mosaic habitats", consisting of agricultural areas interspersed with bushland and well watered by creeks, rivers, dams and the like.

Overgrown vegetation at ground level and lots of cover, especially man-made in the form of tin is also sought after.

In other words they love rubbish tips on the edge of town and are common in suburbs with rocky overgrown gardens, north facing slopes, pools and fish-ponds.

In Melbourne, the suburbs bordering the Yarra River have most Tiger Snakes and of all the Australian capital cities, Melbourne is by far the most heavily infested with Tiger Snakes.

If you are in Melbourne on holiday and want to see Tiger Snakes in the wild, the best bet is to take a drive over the Westgate Bridge and take a stroll across the basalt cuttings around Laverton and Werribee and just look for the piles of rubbish.

You'll find it hard to miss the Tiger Snakes!

Just note that if the weather is cold (usual for Melbourne), then the snakes will be hiding.  If it's warm and sunny, then they'll probably be on the move.

THE DECLINE IN NUMBERS

Tiger snakes are common, but in the last 50 years their numbers have dropped in many areas.

Across inland south-east Australia, these snakes used to be found in their millions, especially along the major rivers of the Murray and Murrumbidgee basins.

Now these snakes are uncommon in these areas.

The decline is due to the intensive agriculture and draining of swamps which was a preferred habitat for the species.  As a known 'frog-feeder', as frogs have died out, so too have the snakes.

It is due to the sharp decline of this genus/species in south-east Australia that these snakes are no longer responsible for most snake-bite deaths in Australia. 

This position is now held by the Brown snakes (genus: Pseudonaja), a snake that prefers rodents and has increased in number in line with the provision of more suitable habitat and food though agriculture.

When the two species have a "face-off" in captivity, the Brown Snakes get right of way, and it'd be fair to assume that the same applies in the wild state.

In Melbourne, Tiger Snakes are more secure.

In fact in many areas, including most inner suburbs, the numbers are on the increase.

As generalists the snakes have adapted to the new urban landscape, especially as older suburbs get more overgrown and rubbish is left along back fence-lines.

In terms of diet, frogs are scarce in many suburbs and the snakes seem to cope well on rodents, which are the dominant thing found in feces of caught snakes.

Big ones are partial to birds and turn up in trees and roofs looking for a feed.

Their feces usually have feathers!

WHERE ELSE DO THEY TURN UP

In Melbourne, Tiger Snakes turn up all over the place!

I've had calls to catch them in houses, on beds, in bathrooms, living in cars, and that includes cars that people drive to work everyday, bird houses, rabbit cages, dog kennels and almost anywhere else you'd care to think of.

I got one snake living in a mid-city bookshop (I caught it under a shelf holding copies of my then best-selling Victoria Police Corruption books).  That snake got into the TV news bulletins, newspapers, radio and so on.

I found another Tiger Snake several floors up in a high-rise.

The snakes travel through the suburbs along fencelines, through drainage pipes and so on.

Hence no suburb in Melbourne is free of Tiger Snakes.

These snakes have literally conquered the place!

Some people say they are a horrible snake in a horrible city!

CAPTIVITY - WARNINGS

I don't need to repeat the risks of keeping deadly snakes.  Nor is it necessary for me to state the obvious that outside Australia getting anti-venom in the event of a bite may be impossible, making these snakes far more dangerous.

However I will give some other warnings in terms of these snakes.

The downside on these snakes in terms of their husbandry is this.

They pass a lot of feces.

I mean this!

You see most snakes eat their food, digest it and pass feces.

Tiger snakes don't.

Instead they pass their feces as they digest their food.

In other words they may typically eat a mouse or two one day, pass their first feces the next day (usually 24-32 hours later) and then pass one or two more feces from the same feed.

In other words if you keep Tiger Snakes, expect to spend a lot of time cleaning their cages!

CAPTIVITY - THE POSITIVES

The snakes are effectively bulletproof.

While there are cases of them succumbing to diseases in collections, including mite-borne ones, I've never lost any and they appear to be about as tough as any snake I can think of in terms of resistance to most ailments.

I've seen Tiger Snakes with afflictions like mites, intestinal parasites and the like, but it'd take a lot of any of these to knock out a Tiger Snake.

Skin worms, which while disfiguring to the scales are harmless to the snake are ubiquitous in wild specimens, including young ones, in which the worms may not manifest as external lumps for months or years after capture.

Books say that the best means to deal with these are to cut out the ones you see (via excision in the skin between the scales and remove by tweezer or similar), apply topical anti-biotic, monitor the snake and then use a strong dose of intestinal worming tablet (for cestodes) which is thought to kill the majority of what's left in the gut.

However, the reverse is actually better and it's best to do the "cutting" about 8 weeks after the intestinal treatment. Why?  It appears that after a "worming" skinworms will migrate away from the digestive tract and appear elsewhere including as new lumps under the skin..

The intestinal worming treatment is most effective if done on a snake with an empty stomach and not by insertion into food.

Which brings me to an important point in terms of this or any other venomous species you may choose to keep.

You must be prepared at some stage to have to forcibly restrain the snake and perhaps force-feed or force-medicate the snake.

If you are not prepared to countenance such possibilities (and any risks that entails), then don't keep the snake.

It's that simple.

Feeding Tiger Snakes?

They're all pigs!

If a Tiger Snake knocks back food, then you probably have a serious problem!

Compared to their wild counterparts, most captives around the place are chronically obese.

As to what you can feed them, well the reality is just about anything.

Most people stick to rodents and these snakes do just fine on them.

I prefer to vary things a bit, the main consideration being cost as rodents don't come cheap when you use lots of them.

To that extent they get rodents, birds, rabbits, whole fish or pieces of fish, lumps of meat, dog bones (usually riblets) and so on.

Based on cost and nutritional value, most of my large snakes, including the Tigers are fed chicken necks, which I buy by the kilo from a butcher.  If they don't woof them down immediately, one or two "trick feeds" will have the snakes eating them.

Rabbits?

Your probably questioning how I could feed a one metre Tiger Snake an adult rabbit.

Simple.

I get the freshly killed corpses off the road and then with an axe and knife chop it into pieces and freeze them.  Some time later (hopefully after most of the unwanted bugs have died), the pieces are thawed out and fed to the snake.

Tiger Snakes love Calamari, crab meat and even eat lobster!

I've even fed them pizza, but don't recommend this as a habit on the basis of it's dubious nutritional value (the pizza was fed to a snake simply to prove a point that Tiger Snakes are liberal with their feeding).

As a handler, Tiger Snakes are hard to beat.  Nine out of ten will settle down and become placid and tractable and never attempt to bite their owner. If you keep these snakes and you are unlucky to get the bad one in ten, you'll know about it.

They usually hiss before they bite.

Tiger snakes do this by a short sharp expulsion of air in a manner rarely seen in other Australian elapids.

The exception to Tiger Snakes being pleasant as captives is in terms of food.

This is what makes these snakes so dangerous.  It's the so-called food bites!

Because Tiger Snakes are eating machines, they'll bite anything they think is food.

Their eating methods also make food bites more likely.

Unlike snakes that strike at food, Tiger Snakes simply move up to it and open their mouth and bite into it.  They then chew it and if the item (or your hand) moves away, the snake merely tightens it's grip and hangs on.

The solution?

Don't allow your Tiger Snake the chance to bite unless it's venomoid.

FANGS THROUGH LOWER JAW

Watch for this, it's common in these snakes.  About 1 in 6 adult Tiger Snakes have their fangs protruding through the lower jaw and hence can envenomate without opening their mouth.

HOUSING

I've seen Tiger Snakes kept in almost anything and they thrive.  They even thrive in cages lined with their own feces, although I obviously don't recommend this.

I've kept them without incident in cages with all manner of substrate (or none), hides, furnishings and the like.

As for most snakes, the essential requirements are heat gradient, clean drinking water and cover to hide under.

As anything else is superfluous, so the minimum is all my Tiger Snakes get.

The basic cage is a plastic tub with air holes as vents.  At the cool end of the cage is a water bowl that must be unspillable.  As the snakes never go in the bowl, they only drink from it, you can get away with filling it almost to the top, without worrying about spillage.

The warm end is heated by a heat mat under the tub and midway in the tub is placed an upturned plastic pot that is sealed at the drainage holes and has a U-shaped "door" cut into the face down upper rim.

If needed, for safety reasons I have a handle on the top of the hide (base of pot), enabling this to be lifted by a hook if required.  The snake will hide in the pot and many soon learn to shift it back and forth over the heat mat to theromoregulate and remain hidden.

As a substrate, newspaper is used.  However for newly acquired snakes this is not used for some months.  Instead I have no substrate.

This is deliberate as it forces the snake to use the upturned pot as a hide.  The snake cannot mess things up by burrowing under paper.

In other collections I see this problem all the time.

After some months and when the snake obviously is likely to remain trained to hide under the pot, newspaper may be used as a substrate, which makes cleaning the cage easier.

Anything extra in the cage is a waste of time and likely to be defecated on anyway, so why bother?

The only issue of note in terms of caging Tiger Snakes is nose rubbing, which is more prevalent in this species than any other large Australian elapid.

This mainly occurs in large wild-caught adult males as they try to escape and move about the cage.

The obvious solution is to have a larger cage.

If however you have a rack-style system of plastic tubs (as I do), and don't want to up the size of the cage, a viable alternative is to use signwriter's sticky label to obscure the clear plastic or glass, save for a small flat area (away from corners) to see in and out of the cage.

This will tend to reduce the rubbing to a level sufficient to enable the problem to correct itself.

Obviously any serious snout injury may take some time to heal as in months and additional treatment with antibiotics or similar may be needed.

Cages sizes?

As a rule, the length should be at least half that of the snake's total.  If your cage is under this length, then nose rubbing may occur.  My largest tubs used for Tiger Snakes are 57 cm long X 38 cm wide X 28 cm high.  The largest Tiger Snake I have is a 156 cm long male and some others are only slightly shorter.  One of the Tiger Snakes rubbed their snout, so as an alternative to putting the snake in a larger tub (which I had for other reptiles), I instead used signwriter's tape to block the clear sides except for a small panel at the front of the tub.  This was sufficient to stop the snake from rubbing and allowed to me to keep the snake where it was.

BREEDING

Add two snakes and watch!

It's pretty much that easy.

Mandatory is cooling of males before intended breeding, otherwise they may not fire viable sperm.

My preference is to "flatline" the males at below 18 degrees as in no heating beyond that level in the heated part of the cage for at least seven weeks.  Then with 12 hours on and 12 off, with heating in the mid to high 20's or low 30's (degrees Celsius) for another 12 weeks is an effectively watertight way to guarantee breeding success.  (This assumes a room temperature consistently below 20 degrees Celsius).

From about a month after the 12 on 12 off heating regime the males will most eagerly mate with females within hours of introduction.

Note, as for most snakes, in Tiger Snakes sexes should be separated in the pre-mating period to give highest chances of success.

Sometimes males will mount females within minutes.

If the male doesn't mount the female within 48 hours, remove it and then try again in a fortnight.

While a lot of elapids won't eat and mate at the same time, this isn't so for Tiger Snakes.

It's not unusual to feed a male and then later the same day put it with a female and watch it mate.

Tiger snakes also mate a lot in late summer and autumn and if the male's sperm is viable, the female will hold it over winter until she ovulates the next season.

MALE COMBAT

It's reported in many books, including that of Shine and other key references, but in terms of Tiger Snakes this is in error.  Based on the fact that males are the larger sex, combat is assumed for the species.  However it doesn't occur in Tiger Snakes.  Males may chase males around cages to try to mount them (sometimes they do) and this could be misinterpreted as combat, but they never fight.  A subdominant male simply allows himself to be mounted by another male.  Combat as in males biting one another or twisting around one another in some kind of "dance" never happens.

SEXING

Most elapids in Australia can be 'tail sexed', as in sexed by simply looking at the tails.

Males have proportionately longer and thicker tails and if enough of a species are seen it becomes easy to tell one from the other.

Unfortunately tail sexing of Tiger Snakes isn't always reliable.

Some with small thin tails do turn out to be males.

As they are trouble free to probe and probing is 100% reliable for these snakes, all should be probed to identify their sex.

Gravid females

Once a female is gravid, experience from other breeders has shown that they shouldn't be overheated or else deformed young are more likely.

Ovulating females appear markedly more thickset than usual in the mid lower body and at this stage should be targeted for mating.  In line with other Australian elapids (e.g. Death Adders), Tiger Snakes can carry viable eggs for some time if there is a delay in mating.

(These snakes are ovoviviparous, as in eggs carried in female (not in a hard shell), and "hatch" when passed as live young).

NEONATES

In line with a lot of Australian elapids, baby Tiger Snakes (about 16 cm at birth) are sometimes tricky to start feeding.  If they fail to eat after their first slough (within 48 hours of it), they should be force-fed or "assist fed" (food placed in mouth).

With Tiger Snakes it's rare to have to do this more than once or twice, as the young snakes are nearly as voracious as the adult snakes.

Young snakes don't have the size or condition or robustness of the adults and as a result should never be allowed to lose condition or emaciate.

Underfeeding and emaciation of young, resulting in death are the most common cause of mortality in neonate Tiger Snakes.

When raising Australian elapids, non-feeders should be force or assist fed (rather than allowed to emaciate) until they reach the stage that they voluntarily eat.  Appetite and willingness to feed increases with age and in time even the most intractable feeders will voluntarily eat.

RACES, MUTANTS, ETC.

While some regional forms may generally vary in temperament (black ones are usually a bit more aggressive), all tend to settle down in captivity, with some occasional exceptions and are identical in terms of husbandry.  That is regardless of what appears to be the dominant food or habitat preferences in the wild state for the given population.

I know of one case of a West Australian Tiger Snake (sometimes referred to as "Notechis occidentalis") mate with an Eastern (N. scutatus) in a snake show in a pit, the result being a perfectly healthy litter of young about 5 months later.

Some years back a Victorian keeper, Barry Searle had some leucystic (white) Tiger Snakes from near Warrnambool in southern Victoria.

Unfortunately the snakes died before they were propagated and hence no unusual mutant Tigers are being kept in Australia at the present time.

For thirty years, Australian herpetologist Raymond Hoser thought of Tiger Snakes as a "junk elapid". After being forced to keep them to do live snake shows, he's now agreed with many of his peers in viewing Tiger Snakes as one of the more enchanting species around.  A pair of Tiger Snakes increased to ten!

Originally published in Reptiles (USA), April 2007.