Acanthophis

Acanthophis
REPTILIAN MAGAZINE - PUBLISHED ARTICLE

AUSTRALIA'S DEATH ADDERS - GENUS ACANTHOPHIS.

BY RAYMOND T. HOSER.

This paper first appeared in THE REPTILIAN MAGAZINE in 1995, What follows is a text only version of the same article (no italics) and without the photos and other material that appeared in the original magazine. Please download the entire article if desired, however if the article is later referred to, please cite The Reptilian Magazine as the original published source. Publication details are that it was published in two parts in Volume 3, number 4, pp. 7-21 and Volume 3, number 5, pp. 27-34.

INTRODUCTION.

Elapids are the front-fanged venomous land snakes. Within this family are the most deadly snakes in the world, including, Cobras (Naja spp.), Coral Snakes (Micruroides), and Mambas (e.g. Dendroaspis). It is only within the Australian continent that this family dominates the snake fauna. Elsewhere in the world, Colubrids are the dominant snakes. Convergent evolution in the Australian elapidae, when compared to snakes in other places is obvious. Small innocuous lizard eating species such as Whip snakes ( e.g. Genera Demansia, Unechis) appear to mimick small colubrid snakes elsewhere.

In Australia, there are burrowing elapids, (e.g. Simoselaps), tree dwellers (e.g. Hoplocephalus bitorquatus) as well as the large well-known deadly varieties, such as Taipans (Oxyuranus spp.), Black Snakes (Pseudechis spp.) and Tiger Snakes (Notechis spp.). Only one group of snakes, the Death Adders (genus Acanthophis) seems to have had convergent evolution with the Viperidae. Death adders are characterised by a broad somewhat flattened, triangular head, short stout body and a thin rat-like tail ending in a curved soft spine. This spine and the presence of subocular scales separates the Death Adders from all other Australasian elapids. Death Adders couldn't possibly be confused with other Australian snakes by anyone with the vaguest knowledge of snakes.

Unless otherwise stated, the following information applies to all species of Death Adder, all of which are similar in most respects. Adults average between 50 and 90 cm in length, usually reaching adult size in 2 to 3 years. Females tend to be the larger sex. All are live bearers. Colour is variable, ranging from red, to brown, grey, greenish-grey, yellow or variants thereof, usually with somewhat irregular crossbands, sometimes dark edged. The tail tip is often a distinctive cream, white or black colour. They have 19-23 mid body scale rows, 110-170 ventrals, single anal, and 35-65 subcaudals (paired and single). Colour pattern is most brilliant in younger specimens and tends to fade with age.

Within Australia there are three species currently recognised. These are the Death Adder, also sometimes erronously called the "Common" Death Adder (Acanthophis antartcicus), Northern Death Adder (A. praelongus) and Desert Death Adder (A. pyrrhus). There may be undescribed subspecies or even species within Australia. New Guinea Death Adders, have been variously assigned to A. praelongus (e.g. Storr 1981, Cogger, 1992), A. laevis ( e.g. Worrell, 1972), and A. rugosus (e.g. Wells and Wellington, 1983). Northern and New Guinea Death Adders are in need of further work to resolve their true status. New Guinea Death Adders are most like Australian A. praelongus in form. However like Australian A. praelongus, New Guinea Death Adders seem to show strong variation in appearance between localities and sometimes within a single locality. Adders (presumably a New Guinea variant) are found in various islands to the north of Australia as far west as Ceram and Tanimbar.

Unless otherwise stated, I shall here treat New Guinea Acanthophis and those from adjacent islands as a variant of A. praelongus. A trait common to many A. praelongus, in particular New Guinea specimens is a raised suracilliary scale above the eye. This feature is often particularly pronounced in immature specimens. It is occasionally seen to a limited degree in young A. antarcticus. A similar trait (often even more exaggerated) is seen in some of the true vipers. No Acanthophis species are rare or endangered. All are widely distributed and common in their preferred habitats. Their preferred habitats vary, but are essentially undisturbed bushland with some form of ground cover. The cover doesn't have to be leaf litter, but can be rocks, native grasses or almost anything else. However any disturbed habitat or grazed areas tend not to have Acanthophis. Acanthophis are most vulnerable to any form of human disturbance and therefore only occur in virgin bush. The construction of a road through such a habitat (with no other development) is not counted as disturbance.

Due to the steady removal of bushland throughout Australia, all Acanthophis are in decline. For a number of reasons, the Death Adder (A. antarcticus), often called "the southern variety" never is found in the same numbers as the other two species. It is for this reason that the name "common" Death Adder really is a misnomer. All Acanthophis are mainly nocturnal and are highly secretive snakes. They spend most of their time half buried in ground litter waiting in an ambush position for food, or simply sheltering. Unlike most other Australian snakes, they tend not to flee when approached, relying instead on their cryptic colouration and camoflague to avoid detection. That this works is indicated by the fact that most bites from Acanthophis seem to occur when they are trodden on.

Shine (1991) documented a radio-telemetry study on an A. antarcticus near Sydney, where although guided by his equipment as to the exact location of the snake, he was still unable to see the half buried snake due to it's excellent camoflague. If an Acanthophis is teased and agitated it will flatten it's body, revealing (what is usually) lighter coloured edges of it's scales. The snake may bite from a rigidly held striking position. From their typical coilied resting position, these snakes are able to make lightning fast strikes at prey or potential aggressors. When they bite a target, they tend to hang on. Acanthophis posess the longest fangs (up to 6 mm) and most developed biting apparatus of any Australian snake.

In line with other venomous snakes, fangs are regularly shed and replaced with new fangs. Old fangs are sometimes seen in faeces and appear to pass through the digestive tract without incident (Hoser and Williams 1991). Due to the toxicity of their venom (about 2,285 mouse lethal doses per milking in A. antarcticus (Worrell, 1972)), Death Adders are regarded as deadly species. (Various publications quote different yields and toxicities. This reflects results of a number of different studies by different researchers, often using different experimental parameters).

Prior to development of a specific anti-venom for Acanthophis, about half of all recorded bites were fatal (Fairley, 1929). The venom is mainly neurotoxic (attacks the nervous system and voluntary muscular system) and about 1.5 times more toxic than that of the Indian Cobra (Naja naja). It is thought that Desert and Northern Death Adders are not quite as dangerous due to their smaller average sizes and venom yields. However, they are still regarded as deadly species. All Acanthophis are presumed to have similar venom (Mirtschin and Davis, 1991).

The world's deadliest snake, the Australian Taipan (genus Oxyuranus) kills about 23,529 mice per bite (Worrell, 1972). Acanthophis bites differ from those of other Australian elapids in that it often takes a long time for symptoms to peak (Mackay 1989, Campbell, 1966). Roy Mackay had a moderately bad bite in New Guinea and his symptoms peaked nearly a day after the bite. According to Dr. Bart Currie of Port Moresby Hospital, the venom usually progresses to maximum symptoms about 24-48 hours after the bite - the danger period. I was once bitten (if that's the correct word) by a 60 cm (approx.) male Death Adder (A. antarcticus) I was measuring, when I stuck my finger down his throat by accident. Although the snake tried to spit out my finger, it's fangs still pierced my skin and I received a decent envenomation. (That was the male snake on plate 26 and the rear cover of Australian Reptiles and Frogs). That was at about mid-day. I experienced local swelling and pain, in line with that of a small moderately venomous elapid (E.g. Demansia psammophis), although the pain was not as acute and piercing. The local pain was duller and more tolerable. After some six hours the only new symptoms was a pain moving up my arm and a distinct reddish colour in the veins reaching up my arm and to my chest. I was admitted to Sydney's North Shore Hospital as a precautionary measure and observed for about 2 days. Symptoms peaked about 20 hours after the bite. By that stage I was barely conscious or able to speak or do much of anything else. When I attempted to speak it was with an uncontrollable slur and others could barely understand what I was attempting to say...my mind was still 100 per cent. I was also barely able to open my eyes. Physically I was very weak (resting in a bed). My pulse and breathing rate, which were being constantly monitored had declined markedly, indicating a substantial bite. At one stage my breathing rate as measured by airflow through my aesophagus was just 10 per cent of normal. In spite of much tension among hospital staff and my parents, I wasn't injected with anti-venom, which was on hand. I made a gradual recovery and when I left hospital after 2 full days had almost totally recovered. The bite area itself continued to ache for some time (a few more days) and had a persistent itch for about 2-3 weeks. Recovery was total.

I received a bite from a young male A. pyrrhus 60 km north of Port Hedland in Western Australia, but symptoms failed to progress beyond local stinging. Similar occurred with the bite from a captive sub-adult A. praelongus from Kunnanurra, W.A..

Acanthophis have highly varied diets, including frogs, birds, small mammals and lizards. Captive A. antarcticus and A. pyrrhus have been known to take live goldfish placed writhing in their cages. Diet obviously also varies with locality. West Head Adders (A. antarcticus), have been known to disgorge frogs (Crinia signifera), while such prey would be absent from areas where other Acanthophis may occur. One 86.5 cm female Death Adder (A. antarcticus) was caught in the wild, having just fed on a large 80 cm Water Dragon Lizard (Physignathus lesueurii). The snake died shortly after due to the lizard's spines penetrating the digestive tract (see Hoser 1981). Acanthophis attempt to capture prey by wriggling their tails (caudal luring), (Carpenter, Murphy and Carpenter, 1978). When the prey animal (such as a native mouse) goes for the tail, the snake strikes at the animal with great accuracy. Even if the animal struggles aggressively, Acanthophis will tend to hang on until the animal is totally subdued (dead).

That a caudal luring snake like Acanthophis often has a different and more brightly coloured tip of it's tail to assist in luring food isn't unique. Other caudal luring snakes such as the Mexican Cantil (Agkistrodon bilineatus) have bright coloured ends of their tail. Some Acanthophis are slow in striking...or so it seems. Specimens with tips of tails missing aren't rare. I have noticed this in a number of wild-caught adult A. antarcticus from around the Sydney area, in particular the Blue Mountains. Although I don't recall seeing A. pyrrhus or A. praelongus with similar "stumpy tails" no doubt such specimens occur. Hungry Acanthophis will sit in their cages twitching their tails even when there is no food immediately available. However this twitching (which appears largely involuntary in such circumstances) becomes more vigorous when an animal like a mouse is walking around one end of the cage. It is because of this caudal luring habit that resting Acanthophis always seem to have their tails positioned just next to their heads. These resting positions aren't arrived at by chance alone!

When I kept Acanthophis I would often throw a mouse (live or dead) across the cage to where the snake was resting. It would be common for the snake to strike at and take the mouse while flying in mid-air. An American film crew teamed up with Herpetologist Graeme Gow to do a slow motion sequence of a Barkly Adder striking at prey, but was unable to get the desired footage due to the speed of it's strike.

KEY TO AUSTRALIAN SPECIES OF ACANTHOPHIS.

1a Head scales smooth or weakly rugose: anterior dorsals weakly keeled or smooth: upper lips boldly patterned with white and black or dark brown...........................A. antarcticus (Death Adder)

1b Head scales moderately or strongly rugose: anterior dorsals strongly keeled (except in juveniles): upper lips not usually boldly patterned............................2

2a Head and body usually bright reddish brown (or reddish brown with blackish markings): head scales strongly rugose: midbody scale rows usually 19 or 21, usually more than 130 ventrals.......................................A. pyrrhus (Desert Death Adder)

2b Head scales usually moderately rugose; midbody scale rows usually 23, usually fewer than 130 ventrals..........A. praelongus (Northern Death Adder)

DISTRIBUTION.

In any given part of Australia there only seems to be one type of Acanthophis. The three recognised species all appear to have mutually exclusive distributions. However a lack of detailed fieldwork in many parts of Australia, in particular the northern half, has yet to resolve the exact distributions of all three species. Hence currently published distribution maps may not be entirely accurate.

The Death Adder A. antarcticus is the southern form. It occurs in well-watered parts of the southern two-thirds of Australia, extending inland in Eastern Australia, with populations extending through inland Queensland to the Barkly Tableland in the Northern Territory. These snakes occur along the southern rim of the Nullabor plain and some nearby offshore islands. They do not occur in the coldest parts of the south-east, including all of Victoria, Tasmania, and the highland areas of south-east NSW.

Heavy agriculture has all but eradicated populations west of the Great divide in New South Wales, although it is presumed Death Adders were common there before Europeans came to Australia. (If the species occurs in Victoria, they would be in either the coastal area adjacent to New South Wales (near Mallacoota) or the far north-west of the state. No populations are known and the rest of the state is apparently too cold). Various geographical races are recognised. Those from the Barkly Tableland are sometimes treated as a different sub-species or even species. They are allegedly the largest Death Adders, although I haven't seen any that are larger than large southern A. antarcticus.

Non-Australian readers should note that in Australia, Death Adders are like the big fish that got away...everyone reckons they've seen the biggest Adder of all. For the record, Barnett and Gow (1992) state that the largest female Barkly Adders are known to attain 1300 mm (over 4 feet), making them far larger than anything lodged in Australian museums to date. (Newborn Barkly Adders appear to far larger on average than other A. antarcticus, based on the records of Barnett and Gow). Barkly Adders tend to have a more bluntly shaped head than southern A. antarcticus and other differing characteristics. There is however a strong overlap in these characters between Barkly Adders and southern specimens.

Wells and Wellington (1985), called the Barkly Tableland Adder Acanthophis hawkei, after the then Prime Minister, Bob Hawke. Chromosomal tests by Greg Mengden at Australian National University have revealed differences between Barkly and Southern Death Adders, but most people still regard both as being A. antarcticus. Those from Dutchess or Djarra, (towns in hill country south of Mount Isa, Queensland), appear to be slightly more rugose than other A. antarcticus, but are otherwise similar. Click here to see a photo of one of these Death Adders. Another variant occurs near Camooweal on the Queensland/NT border. Although some colour variants are widespread, others appear to be more restricted in distribution. These variations sometimes correlate with soil or vegetation regimes, but are in fact genetically determined. Natural selection pressures would dictate which colour variants predominate in a given area. For example around Sydney, A. antarcticus are either red or grey in base colour. There are no other variants or intermediates.

A study of a typical population in Sydney's Kurringai Chase National Park revealed 28% homozygous grey (grey morph), 50% heterozygous red/grey (red morph) and 22% homozygous red (red morph)(Hoser, 1985). (A similar scenario seems to be seen in some north Queensland populations of A. praelongus, including those around Cairns). Shine (1991) seemed to think that in warmer climes, selection pressure favoured reddish individuals over greys, but in Acanthophis this may not be so, other factors being more important. The Northern Death Adder (A. praelongus) is found in the tropical north of Australia (see map). This species also displays strong regional variation in size and colours. North Queensland specimens are different to those from the Northern Territory and Western Australia. Those from the Northern Territory are divided by some local reptile people into the lowland/floodplain form (brown with darker crossbars) and the supposedly smaller hill-country form (lighter and without the distinct brownish crossbars). I have seen specimens of both forms and they are clearly different in colour. However I am uncertain as to whether intermediates occur, or if these are simply genetically determined variants within a single or adjacent populations.

Those I have seen from the Kimberley in Western Australia appear to be similar to the N.T. hill country form. British Herpetologist, Mark O'Shea speculates that within New Guinea, there may be up to three species of Adder, but he stresses that he really doesn't know the true status of these snakes and that further work is urgently needed. Most Adders seen in Europe and the USA are from New Guinea and Islands to the West. Desert Death Adders (A. pyrrhus) appear to be restricted to arid parts of Australia, including arid parts of Western Australia (most of that state), the Southern two thirds of the Northern Territory and northern South Australia. Texts such as Cogger (1992) and others state that they are found in arid areas of all mainland states except for Victoria. If they are found in New South Wales, they would only be found in a small part of the far north west of that state.

Swan (1990) does not record Desert Death Adders as occuring in New South Wales. Any populations in Queensland would also have to be in the far south-west of that state. No photos of greyish specimens of A. pyrrhus are known. Nor are any grey specimens lodged in Australian museums. This is probably due to strong selection pressures against this gene; most of the range for this species is red soil areas. However I have been advised that greyish specimens do in fact exist. In the Millstream, Pannawonica and Newman areas of the Pilbara in Western Australia some Desert (?) Death Adders appear to have strong blackish markings, especially on the head, which may be almost completely blackish-brown dorsally. Mirtschin and Davis (1992) and Ball (1993) speculated that this was an undescribed species, but that view hasn't been shared by everyone who has seen these snakes. Normally patterned red-morph Desert (?) Death Adders and some with intermediate markings have been found in the same area. Laurie Smith of the Western Australian museum, has stated that he believes that there are at least two species of snake currently identified as Desert Death Adder, but as yet hasn't published anything to support that assertion. He doesn't believe the darker Pilbara snakes are different to other Desert (?) Death Adders in the same area. (Refer to later paper published describing new species, incl. A. wellsei - Hoser 1998).

Within dry and arid areas, Acanthophis are most commonly found in large numbers in relatively undisturbed areas of spinifex (Triodia sp.) grasslands, particularly when associated with rocky hills. Most other areas have of course been trampled by domestic and feral animals. In Western Australia, Northern Death Adders are also most common on spinifex covered hills. Besides habitat destruction causing a major impact on Acanthophis populations throughout Australia, other factors are hastening their decline in numbers. The introduced Cane Toad (Bufo marinus) has also decimated numbers. Snakes that feed on the toads die as they have no protection from their poison glands. Collectors have seen dead adult Acanthophis with toads still in their mouths. Young snakes are eaten by larger toads. To date the most serious declines caused by toads have been in coastal Queensland north of Brisbane, where the toads are most numerous. Toads have been the principal cause of decline in Death Adder (A. antarcticus) numbers around Mount Glorious, Queensland (near Brisbane). Formerly common in the area, they are now infrequently seen. Near Mount Glorious, most A. antarcticus are now seen near Samford, which has the least toads.

FINDING ACANTHOPHIS IN THE WILD.

To capture Acanthophis in Australia, one needs a permit issued by the relevant state wildlife department. This is true even if the snake happens to be walking through your living room at home or back yard. Failure to have the correct "paperwork" can result in prosecution, heavy fines and even jail. Assuming one has overcome the legal problems, which is an achievement in itself, finding Acanthophis in the wild isn't too hard, provided one uses the following guidelines. (See Hoser (1984a) for how NOT to go about looking for Acanthophis). The best way to find these snakes is by driving along a road at night through preferred habitat and catching them as they cross. To find just one of these snakes at night would please most snake enthusiasts. In the case of A. antarcticus, to find one alone on a good night (optimal weather conditions), is in fact a lucky haul. The highest numbers of each species I am aware of being found by a single collector on a single night are as follows:- A. antarcticus: 15 in South Australia, near Eucla (5 on West Head/Cottage Point, 7 Near Dutchess/Djarra, Queensland) A. praelongus: 75 South of Darwin in Northern Territory during a flood - the road was the highest point in a flooded area. A. pyrrhus: 125 near Sandfire Flat/Goldsworthy, Western Australia. (100 during day near Marble Bar, WA, during a burnoff at a disused airport runway). Also bear in mind that when these snakes were found, other species of reptile were also seen.

A check with herpetologists, or a number of reptile books will yield locations where Adders are known from. Near Sydney, the National Parks to the north, south and West (Kurringai, Royal and Blue Mountains) all have Acanthophis. Good spots can also be found close to Brisbane, Perth and Darwin, while a few hours drive will get you into good Acanthophis country if in Adelaide. Photos of optimal habitat (all three species) is shown in the book Australian Reptiles and Frogs (Hoser, 1989). To run around during the day looking for these snakes is usually a waste of time. You really need to fluke it to find a one during the day. It does happen, but is very, very rare.

Acanthophis is the ultimate "front snake". That is when the weather is unstable (usually hot) and a cold front is approaching, the snakes will move about. For those in the southern half of Australia, to go hunting Acanthophis at any other time is usually pointless. There is usually a minimum temperature, below which it is rare to find Acanthophis active at night. Around Sydney, the minimum is about 24 degrees celcius. In Brisbane it is higher, (26 degrees), and in far northern Australia, usually higher again. Remember these temperatures are minumums, not preferred. Preferred temperatures are higher. Around Sydney, the preferred activity temperature for Death Adders (A. antarcticus) is probably closer to 26 degrees celcius (Hoser, 1984b). In the West Head (Sydney) area, the coldest temperature I have found an active Death Adder (A. antarcticus) was 17 degrees celcius. This adult male was found at night immediately following arrival of a cold front (less than ten minutes) and the air temperature had rapidly dropped from 25 to 17 in that period. Two other Adders had been caught earlier the same night.

The hottest air temperature I have caught a Death Adder (A. antarcticus) active was 38 degrees when a sub-adult female was caught at dusk five minutes prior to the arrival of a cold front. It is notable that both above referred to snakes had been hit by a car immediately in front of my own and both snakes died within a few hours of capture. Most Adders are caught at night in the West Head area, when the air temperare is in the mid to high 20's (celcius). Over 30 degrees and it is usually too hot for the snakes and they don't seem to move (around Sydney anyway), under 24 and it starts getting too cold. (captive snakes display altered activity patterns in relation to outdoor air temperatures). Moonlit nights are also bad for most snakes, including Acanthophis (Ball, 1993). The moonlight enables nocturnal birds of prey to feed on the snakes and so the snakes don't move about. Birds of prey are particularly numerous on moonlit nights. As the hottest part of the night is immediately after dusk and the moon goes in monthly cycles, the best time to go Acanthophis hunting is in the fortnight starting a few days after the full moon (when there is no moon in the sky for at least the first part of the night). The same applies for most other snakes, except those that are black and white in colour which often appear not to worry about the moon so much. This is apparently because their colour helps them avoid detection by birds of prey as they move about at night.

Although Worrell (1972) records Acanthophis in New Guinea being most active at the end of the Wet season (around Feb-Apr), my own experiences suggest that temperature is more important in determining activity than humidity. In times of drought when other species appear to become scarce, Acanthophis numbers and activity patterns appear to remain normal. Ball (1993) believed some Adders (A. pyrrhus(?)) became active and prevalent in an area in response to the presence of frogs as food. Such may also explain increased activity by Acanthophis in New Guinea at the end of the wet season. Nights of extremely low humidity appear to yield just as many Acanthophis as humid nights provided temperature and other criteria are met (i.e. darkness of night, falling air pressure, etc). Around Sydney it is common for the lowest humidity nights to also be the warmest (with north-west winds, as opposed to the more common and cooler sea breezes), and those are the nights you find Adders! When night driving in the Pilbara, nights with most rain were often too cool for Desert Death Adders to be active (after the rain), thus less tended to be caught on these nights (if the rain fell before and during dusk). These nights were also usually the best frog nights.

As cold fronts accompany/follow most hot nights in Southern Australia, the need to worry about them isn't usually necessary, provided the temperature is right. However the temperatures indicated (above) apply to the time of driving (after dusk), NOT what the temperature gets to during the day preceding the night hunt. As already stated the best way to find Acanthophis (and many other nocturnal snakes) is to drive along little used roads through suitable (known) habitat. Bitumen roads are strongly preferred over dirt roads for several reasons, the main one being that it is easier to see snakes crossing the roads and one can travel faster along them. Snakes do not tend to bask on roads, contrary to popular belief. For those who may think that roads tend to store heat better than ground elsewhere (in adjacent bush) I suggest they try putting their hands on the road surface at night and then do the same on an open patch of dirt away from the road. There will be little if any difference. At night a (quiet) road effectively becomes a simple strip of bush and snakes cross them as they need to. The snakes are usually very easy to see, so to maximise the number caught it is advisable to drive as fast as possible (legally and safely) as one can.

Snakes seen coiled up on a road as opposed to the usual "crawling somewhere mode", have almost certainly been hit by a passing car and been terminally injured. A snake coiled on a road is NOT a natural position. Tens of thousands of snakes, including thousands of Acanthophis die on Australia's roads annually. Acanthophis are relatively slow moving and therefore easy to capture when found crossing roads. The only exception to this is with Desert Death Adders which move with suprising speed in a sidewinder-like motion when startled crossing a road. My own experience is that I usually miss at least one in ten Desert Death Adders seen crossing roads. Those snakes disappear into roadside vegetation before they are caught. Most Acanthophis caught crossing roads are males. These snakes are presumably looking for mates. The sex ratio for adults found crossing roads is about 1 female for every ten males seen. For juveniles the ratio is more even. This approximate ratio has been arrived at over many hundreds of specimens.

Ball (1993) only found one female out of 20 Adders caught crossing roads in the Pilbara. This night-hunting sex ratio is not necessarily a true picture of Acanthophis numbers. My own breeding results showed an even sex ratio at birth. Assuming males to be the more mobile sex (they are the ones looking for mates), there could in fact be a marginal skewing of populations in favour of females, with more males being vulnerable to predation). Shine's studies have indicated similar. When breeding Barkly Adders, Gow and Barnett appeared to get a 2F:1M sex ratio in offspring. Whether their results were unusual or typical of the "race" is yet to be determined. The 2F:1M result documented came from two separate breedings of related snakes that were housed in collections 3,000 km apart. Acanthophis found during the day are usually found by chance.

One enterprising man (Kaj Bulliard) claimed success in finding Death Adders (A. antarcticus) near Sydney by using a Ryobe (tm) Leaf Blower to clear leaf litter in likely spots (under Blackboy (Xanthorrhoea sp.) bushes and similar) to expose resting Death Adders. Others, including myself have spent many hours using rakes to clear leaf litter without success. West of Sydney, there is a creek called Fitzgerald Creek, near Glenbrook, which runs into the Nepean River. It flows through a gorge. At the bottom of the gorge about ten Death Adders (A. antarcticus) were caught resting on ground near the creek by a number of reptile people. All were caught in the period February-May.

Although none were found in immediate proximity to one another (as in a few feet apart) these finds did represent the closest thing known to date of aggregation in Death Adders. Aggregation as such in Acanthophis is unknown. Male combat in the wild or captivity has never been observed. My own males, when housed togeather usually appeared to ignore one another, although I did note it was relatively unusual for two males to attempt to mate the same female at once. Stettler (1985) believed that his male Acanthophis did have social interactions and formed some sort of social hierarchy. Further study is required.

No specimens have ever been taken from inside termite mounds - even in areas where (Desert) Death Adders are common and many termite mounds were opened up (Hoser, 1992). When capturing wild Acanthophis it is best to pin the snake with a "jigger" stick, which consists of a long stick with a small fork at the end and stretched rubber between the ends of the fork. The snake is pinned somewhere on it's mid or forebody with the jigger and using a second similar stick, the head and neck is pinned. The snake is then picked up and placed in a bag.

Captive Acanthophis will become used to being picked up and moved about with a simple hook, negating the repeated need to roughly handle the snake in a manner likely to upset them. As captives they become relatively easy to handle, although Desert Death Adders may remain "flighty" after some time in captivity - particularly if rarely handled and kept in a spacious cage. Non-Australian readers do have access to Acanthophis. Larger American reptile dealers and those who specialise in venomous snakes do occasionally get specimens. I have seen all three species on price lists in the United States. The most commonly sold are "Indonesian" specimens, which usually sell for about US$ 100-500 each.

CAPTIVITY.

Within Australia Acanthophis are by far the most sought after venomous snake by herpetologists. There are several reasons for this, not the least being the fact that there is no other Australian snake like them. They are also extremely easy to keep, being almost impossible to kill. Although theoretically prone to all the usual snake ailments, Acanthophis rarely succumb to them. I have seen Death Adders (A. antarcticus) get over mite infestations that would have killed most other reptiles. These snakes barely showed any ill effects. I've seen wild-caught specimens covered in ticks, again without apparent ill effect. Once I had a pest strip dripping into a water bowl in a cage with A. antarcticus for several months. No snake showed any ill effects.

On another occasion a male Desert Death Adder had a terrible mouth infection. It responded well to anti-biotics. The snake made a 100 per cent recovery. Some captive Death Adders (A. antarcticus) appear to become darker in colour when held in captivity (see Hoser 1985b). There is no known reason for this, nor has any seasonal correlation been noted. I have noticed this trend in both red and grey snakes. The cause may have something to do with the temperature/s the snakes are kept at. Colour changes in response to captivity are known in several other species of Australian snake. Average sloughing rate is about 3.1 times per year, (based on 14 snakes over a total of 419 months), although fast-growing and young specimens tend to have a higher sloughing frequency (Hoser, 1982).

Acanthophis usually slough in one piece, and repeated failure by a captive snake to do so may indicate a health problem that needs to be addressed. I have never observed Acanthophis soaking prior to sloughing or heard of captive specimens having difficulty in doing so. This is except for some minor problems experienced by Mirtschin, who had snakes which had piecemeal sloughs. He thought this was due to excessive dryness in his cages which tended to lack cover. When feeding snakes in group cages I often had snakes bite and chew one another, with no adverse effects on one another (Hoser 1985c). That appeared to indicate immunity to venom by these snakes. Stettler (1985) and van Woerkom (1985) documented a case involving apparent non-immunity to venom in Acanthophis from unknown locality whereby two apparently healthy snakes died from bites from a fellow Acanthophis that was part of the same litter. Although the cause of death may have been something other than venom, this whole area needs further investigation.

Cannibalism isn't known in Acanthophis, except for Desert Death Adders where it can be a major problem, particularly in young specimens. (See Hoser 1998 for cases in other Acanthophis). In my own experiences, some specimens have far stronger cannibalistic tendencies than others. Gow (1981) and others documented cannibalism in young Desert Death Adders. My own experiences related to an adult male from Goldsworthy, Western Australia, who on one occasion ate a fellow male roughly the same size before regurgitating him dead. They shared the same cage together and food was not on offer at the time. On another occasion, the same snake ate a slightly smaller female A. antarcticus before regurgitating her dead. Again no food had been on offer.

In other words, for Desert Death Adders at least, it is advisable to keep snakes in separate quarters. It goes without saying that all snakes should be watched when fed, to ensure that no two snakes go for the same piece of food. In terms of how to house Acanthophis, they seem to survive and breed in all manner of set up. Brian Barnett successfully keeps Acanthophis in shoe-box style cages. He has bred Barkly Tableland A. antarcticus and Northern Death Adders (A. praelongus). Mine were kept in modified fish tanks and display cases with hardened clay substrate with "underground" cables as the primary heating source. Leaves acted as cover for the snakes. These leaves became optional over the years as they really weren't necessary. I was able to take better photos of the snakes in their cages when there weren't leaves to obscure the view.

Captive A. praelongus (Indonesian specimens) I saw held by Tom Crutchfield in 1993 in the United States were kept successfully in the same shoe-box style accommodation used to successfully breed most colubrids. It goes without saying that a water bowl should be provided at all times. Young specimens and Desert Death Adders seem to show a strong preference for lizards over mice. Once Acanthophis are large enough, mice are the recommended food, although they will also survive adequately on alternatives such as hatchling chicks. There are various ways to "trick-feed" Acanthophis to convert them to mice. I used to use chopped up bits of lizard tied (with cotton) to a freshly killed mouse and fed as a single lump to the snake. The food item would be jiggled in front of the snake with tongs and the snake would take it, eating the lizard part first, with the connected mouse being swallowed at the same time. I used to chop up my lizards as they were too precious to waste one at a time on the snakes. Others have had success simply rubbing lizard over the mouse to "scent" it. I had no success with this method.

Although Acanthophis will readily eat frogs (see Shine, (1980) for a detailed analysis of what wild Death Adders will eat), these are not recommended due to the heavy parasite burden carried by these animals. Although I never had parasite problems with my Acanthophis, Taronga Zoo in Sydney reported Ascarid (blood parasite) problems with some of it's Desert Death Adders. On (extremely) rare occasions that Acanthophis have had to be force or "assist"-fed, this has not posed any problems.

BREEDING IN CAPTIVITY.

Death Adders (Acanthophis antarcticus) have been bred more frequently than any other Australian elapid. For documented cases see Hay, (1972), Hoser (1983, 1987), Hudson (1979), Johnson (1987), Mirtschin (1976, 1982, 1985, 1991), Barnett and Gow (1992). Barnett and Gow have both bred Barkly Tableland Death Adders many times and their results show little differences to those for cases involving other A. antarcticus. For documentation of breeding Desert Death Adders see Fyfe and Munday (1988). Northern Death Adders have been bred by Brian Barnett on a number of occasions. According to Barnett the average litter size for his female is about 10.

Sexing adult snakes is easy. The male has a distinctly larger and thicker tail. This is easily noticed when males and females are put side by side, or by anyone who regularly observes Acanthophis. Males often slough their hemipenes (Stettler, 1985). Immature specimens are sometimes harder to sex, especially in Desert Death Adders. However all Acanthophis can be readily sexed by probing (which is explained in most snake keeping books). Fairly standard snake husbandry techniques will ensure success. Both sexes MUST be cooled over the winter prior to planned mating. My initial failures in attempting to breed Death Adders (A. antarcticus) were solely as a result of my failure to cool my males. Once I started doing this, I couldn't help but breed Death Adders.

Males mate in similar stereotyped fashion to most other snakes (see Hoser, 1983 for details of Death Adder mating behaviour and Carpenter and Ferguson, 1977, for details of stereotyped sexual behaviour in reptiles). In summary, the male snake will mount the female and align his body over that of the female. The male will rub his chin over the female and flatten his body in a bid to cover the female's (usually larger) body. The male will attempt to lift the female's tail to expose her vent with his own tail. In response, the female may rapidly twitch her own tail and either oblige (if receptive) or if unreceptive either flee the male and/or sit on her tail/vent region so that the male cannot easily copulate. During copulation, the male snake will have caudo-cephalic twitches, in particular around the neck, far lower body and tail. The orientation of the snakes becomes less important during the course of actual copulation. As the female snake moves about, the male will attempt to keep his body in the original orientation. This is probably due to the fact that this is the most comfortable mating position for the snake. Successful copulation tends to last for a few hours, but appears to range from a few minutes to several hours and possibly even days. Prior to mating, males will tend to go off their food and pace their cages. If this behaviour isn't displayed, then the male probably won't want to mate. On rare occasions, males will mate shortly after feeding. Females on the other hand will feed normally during the mating season and early pregnancy. They will even eat while copulating!

My own Acanthophis didn't seem to object to being photographed while mating. On one occasion (8th May 1981), two mating Death Adders (A. antarcticus) were free handled by thieves (while connected), had cigarettes ashed on them and yet they still continued to mate without attempting to break up! Although males of all species of Acanthophis will mate other species of Acanthophis, they do tend to prefer mating their own species and will do so if offered a choice (in a captive situation). Extremely highly sexed males will attempt to mount other males if no females are present in the same cage. This even applies with Acanthophis of different species. It is not rare for a male Acanthophis to run down condition fairly sharply when mating over a period extending up to two months. Overfed males tend not to be as sexually active as leaner (not necessarily thin) males. This situation also occurs for other types of reptile. In spite of a warning to readers to watch the condition of males when mating, I have never had a male run itself down beyond the point of recovery.

Copulation usually appears to be terminated by the female. This is usually done when she crawls off, dragging the male along behind her by his still joined hemipenis. Mating behaviour is most likely during times of outside temperature and air-pressure changes. In a captive situation, it is best to plan matings around these conditions. Although Acanthophis that are housed together will mate readily, separation of sexes strongly increases the eagerness of males to mate. Not all matings will result in pregnancies. Acanthophis will mate at any time of year, although most activity seems to be concentrated around Autumn and spring, which is also when most successful matings also occur. Although it is thought that at least some Acanthophis have some sperm storage capabilities, no investigation of this has yet been done. In Hay's (Hay, 1972) case, his female hadn't mated for 12 months before giving birth. Gow and Barnett (1992) quote a "gestation" period for Barkly Adders of, 142, 147 and 161 days in three cases. The figures quoted by Gow and Barnett tend towards the shorter end of the spectrum for successful matings in Acanthophis (those "gestations" at the short end of the spectrum are also the most commonly quoted). For my own breedings, the successful matings (that resulted in young being born) were deduced to have taken place some 6-9 months earlier, (there were either no other matings or possibilities in all cases). Assuming that young Death Adders develop in a similar manner in all cases, sperm storage is indicated in Acanthophis by the experiences of Hay and myself. Further research into sperm storage capabilities of Acanthophis is required.

I am unaware of records of captive breeding of Acanthophis outside of Australia, but see no difficulties in such taking place. Most Acanthophis (all species) breed only every second year. This is genetically pre-determined and contrary to popular belief is not influenced by food intake or general condition of the female prior to a given breeding season. Occasional individuals (females) are able to breed every year, and will do so in captivity. Following successful mating in Autumn or spring, all Acanthophis give birth in summer and early autumn (Late January to Early May). For A. antarcticus The number of young born are known to range up to 33. Based on dissections of museum specimens, Shine found the average litter size for the species of 8.

Other documented litters include the following:- 24, 19, 10, 24, 11, 18, 17, 27, 24, 16, 33, 22, 25, 16, 14, 20, 23 (Mirtschin, 1985), 27, 7, 7, 1, (Hoser, 1987), and 20, (Hay 1972). In my case where 27 young were born, 12 were still-born and a further 6 unfertilised ova were produced. Had those six ova also been fertilised the total litter would have been 33. In the second Mirtschin litter of 24, there were also 13 unfertilised ova. Had they been successfully fertilised, the litter would have been 37. In other words it is likely that a large A. antarcticus could concievably give birth to over fourty young, although a litter of that size has yet to be recorded. This makes A. antarcticus potentially one of the more prolific elapids.

For Barkly Adders litters of 19, 19, 22, 18, 16 are known (Barnett and Gow, 1992). Documented litters for two Desert Death Adders were 13 and 11, (Fyfe and Munday, 1982). A common problem noted by many breeders has been the high number of stillborn and deformed young, and unfertilised ova (all types of Acanthophis). While it is uncertain if these problems are restricted to captive breedings or also found in wild specimens, my own belief is that such probably also occurs at least to some extent in the wild. In 1978, American herpetologist Ron Sayers removed a road-killed Death Adder from West Head Road. Inside were a number of nearly fully developed young. Sayers also noted unfertilised ova (soft eggs).

For many years I bred large number of Cunningham's Skinks (Egernia cunninghami) in very natural surroundings. I had recurring problems of some females giving birth to large numbers of still-born young and assumed that it was a result of something to with captivity. However when subsequently doing extensive fieldwork in E. Cunninghami habitat near Oberon, NSW, during the birthing season (late summer/Autumn) I noticed dead young (stillborns) on a number of rock outcrops. This indicated a similar problem in wild specimens. That I was able to notice such was in itself significant as under normal circumstances other predators such as ants or birds would rapidly eliminate such things. Mirtschin has postulated that deformities and stillborns may result from the females being kept at unsuitable temperatures during pregnancy (too hot). Firm data is not yet available however.

Prior to giving birth, females become restless and will move about the cage more than usual. They will usually, but not always, stop feeding prior to giving birth. Females have been noticed appearing to burrow under leaves or logs to form a sort of "nest" prior to giving birth. They also tend to lie in an open circular arc, although this habit appears to be distinctly more noticeable in some females than others. The posture is presumably a response to being gravid (pregnant) and the snake simply seeking the most comfortable position. Some Acanthophis give the appearance that they are about to explode with young before giving birth. They swell to such a degree that the skin between the scales becomes clearly visible. In cases where the number of young is fewer, such doesn't necessarily occur. Birth usually occurs (in southern Australia) following passage of a cold front when weather tends to be seasonally cooler, more humid and often wet. This also applies to specimens kept indoors, which are supposedly divorced from such climatic activity. Acanthophis and many other reptiles do, when kept indoors seem to react to outside weather patterns, in line with their wild counterparts, even when in completely sealed and temperature controlled rooms. Clearly these snakes are sensitive to even the slightest of weather changes. An A. antarcticus of mine took 250 minutes to give birth to 27 young. From what I can gather, the rate at which this snake gave birth was fairly typical, but the number of offspring was higher than average, indicating a slightly longer than average birthing time. 11 young were passed in the first five minutes with the rest being born at relatively even intervals in the 245 minutes after that.

Documented sizes of newborns varies. Newborn Sydney Death Adders ranged downwards from 169 mm (total length) averaging just over 160 mm (Hoser breedings). Other Sydney breedings have yielded similar sized young. Hudson (1979), quoted a range of 93-139 mm for ten newborn A. antarcticus from South Australia. Although the figures quoted were "total length" they may have in fact been "snout-vent" based on their apparent size. Barkly Adders range down from 245 mm, averaging somewhere in the vicinity of 235 mm (Barnett and Gow, 1992). For A. pyrrhus, Gow recorded an average total length of 162.16 mm for his 13 newborns. Fyfe and Munday cited a range of 127-150 mm for 11. For A. praelongus, nothing is recorded, although it is presumed hatchling sizes would vary in line with sizes of the adults. In other words comparable to those sizes quoted above. Feeding in young usually commences after the first slough. It is after this point that cannibalism in young A. pyrrhus can become a problem and should be guarded against by separation of all young from one another.

Shine (1981) found that in the wild, male Acanthophis mature at about 24 months, while females mature at about 42 months. This was based on Museum dissections of various species (all lumped together). Local populations may vary slightly on this basic pattern. Captive Acanthophis tend to mature much earlier, the exact rate dependent on feeding and temperature of the young snake. It is common to have both sexes mature within 24 months in a captive environment. As a snake, Acanthophis lend themselves to being kept and bred in large numbers. Hopefully in the future they will be more commonly seen in captivity.

A NOTE ON SNAKEBITE.

As a potentially dangerous snake, care should always be exercised when keeping and handling Acanthophis. Having said this, many keepers of these snakes go for many years without incident. Common sense will always work to avert accidents. Non-Australian keepers may be well advised to seek out and obtain a vial of Anti-venom as a safety precaution in the unlikely event of a serious bite. A further warning is that Anti-venoms (obtainable from the Commonwealth Serum Laboratories, Poplar Road, Parkville, Melbourne, Vic 3052, Australia) have a limited "shelf life" so must be periodically replaced.

CONSERVATION.

As already mentioned, the biggest cause of decline for Acanthophis in Australia is habitat destruction. Acanthophis don't appear to be compatible with any form of livestock or overgrazing, even by feral animals. Death Adders (A. antarcticus) have been extirpated from wide tracts of New South Wales and inland Queensland where they were once common. Old literature shows that Death Adders (A. antarcticus) were widespread and common throughout inland Queensland in an area known as the Brigalow. Following mass clearing and introduction of Prickly Pear, in the southern two thirds of inland Queensland, Death Adders appear to have become extinct in all but a few isolated pockets. The principal cause of extinction was livestock over-grazing possibly aided by further land clearing and feral animals such as cats.

A similar picture has happened to a lesser degree in other parts of Australia. Continued overgrazing of many arid areas will not help populations of Desert Death Adders. Cane Toads (Bufo marinus) continue to spread in Northern Australia and assuming their spread remains unchecked (which is likely due to government indifference at the problem), Cane Toads will eventually populate all of the top half of Australia, excluding arid areas. This may well spell disaster for many as yet unharmed populations of Northern Death Adders (A. praelongus). These snakes apparently disappeared from the Mt. Molloy area of north Queensland following invasion by Toads. Gilbertson-Middlebrook (1981) noted large-scale mortality of Death Adders (A. antarcticus) and other native reptiles on South Australia's Yorke Peninsula, following the laying of a strychnine based poison to control a plague of introduced European mice (Mus musculus). It is presumed that the snakes had died from secondary poisoning after feeding on infected rodents.

Feral cats and foxes are known to prey on huge numbers of native reptiles, including Acanthophis, but along with road kills and urbanisation, these threats are not usually regarded as critical for Acanthophis. It is thought that the impact of these problems is either tolerable for given populations, or in the case of urbanisation, only highly localised. Australia still has less than 20 million people in an area comparable in size to the United States, which has about 265 million. Further investigation of the adverse effects of feral mammals on all Australian reptiles is required. Herpetologist Brian Bush believes declines in A. antarcticus numbers on the mainland of south-west Western Australia are a result of feral cat and fox predation. He notes the relative abundance of A. antarcticus on some offshore islands that lack feral pests. Wildlife laws in this country are greatly damaging any efforts to conserve Acanthophis in the short, medium and long term. Taking specimens from the wild is banned, even if the snake in question is about to be killed. While it is legally acceptable to run over a snake on a highway, a person may be jailed for rescuing the same.

Recently in Sydney, the New South Wales National Parks and Wildlife Service (NPWS), threatened to charge and jail a Miss Marilyn Marchant after she rescued a Diamond Python (Morelia spilota) crossing the main Pacific Highway during a bushfire in early 1993. She was only let off the hook because a member of parliament intervened and pulled the department into line.

In another case, NPWS actually prosecuted a licensed snake keeper for breeding Death Adders (A. antarcticus). You see the problem was that NPWS refused several written requests to issue a permit for unborn snakes. When the snakes were born, the keeper duly notified NPWS of his new snakes. He was prohibited under the terms of his general scientific licence to move any reptiles from his house, where they had to be retained. As these newborn snakes were excess to the number he was licensed to hold, he was duly prosecuted and fined $1,000. The fine was overturned on appeal to a higher court, but it cost the keeper $2,000 in legal costs to do so, making him even worse off. The court documents had unequivicolly stated the NPWS charge of "Illegally breed Death Adders.". No wonder many people in Australia don't dare attempt to keep snakes in captivity.

Further examples of idiocy among wildlife officials and laws in this country can be seen in the book Smuggled - The Underground Trade in Australia's Wildlife (Hoser 1993), or the Sequel, Smuggled-2, published in October 1996 and now available). Of course with insufficient numbers of Acanthophis in captivity, a Rheobatrachus-like disaster, where the species is common one day and extinct the next, becomes all the more likely. This in spite of all Death Adders not currently being regarded as endangered species. See Hoser (1991) for details of the (presumed) extinction of the Gastric Brooding Frogs (Genus Rheobatrachus), and other Australian species. This country urgently needs a radical overhaul of it's wildlife laws and related bureaucracies. Until governments allow Australians freer access to wildlife, instead of locking it away from the vast majority, more species will perish. This sentiment has been echoed by innumerable authors. Pages and pages of papers and articles echoing similar sentiments are cited at the rear of the books Smuggled and Smuggled-2.

LITERATURE CITED.

Ball, S. (1993), 'Further data on the Pilbara Death Adder - A suspected New Species', Monitor, Bulletin of the Victorian Herpetological Society, 5 (1), pp. 5-10.

Barnett, B. F. and Gow, G. F. (1992), 'The Barkly Tableland Death Adder, Acanthophis antarcticus', Monitor, Bulletin of the Victorian Herpetological Society, 4 (1), pp. 13-23.

Carpenter, C. C. and Ferguson, G. W. (1977), 'Stereotyped behaviour in reptiles', in Biology of the Reptilia, Academic Press, Vol. 7, pp. 335-554.

Carpenter, C. C., Murphy, J. B. and Carpenter, G. C. (1978), Caudal luring in the Death Adder (Acanthophis antarcticus (Reptilia, serpentes, elapidae)), Journal of Herpetology, 12, pp. 574-577.

Cogger, H. G. (1992), Reptiles and Amphibians of Australia, Revised Edition, Reed Publishing, Sydney, NSW, Australia. 775 pp.

Fairley, N. H. (1929), 'The present position of snake-bite and the snake bitten in Australia.', The Medical Journal of Australia. March 9th, pp. 296-313.

Fyfe, G. and Munday, B. (1988), 'Captive breeding of the Desert Death Adder (Acanthophis pyrrhus)', Herpetofauna, 18 (2), p. 21.

Gilbertson-Middlebrook, K. (1981), 'A note on Death Adder mortality following the laying of poison', Herpetofauna, 12 (2), p. 36.

Gow, G. F. (1981) 'Notes on the Desert Death Adder (Acanthophis pyrrhus) Boulenger 1898, with the first reproductive record.' Northern Territory Naturalist, 4, pp. 21-22.

Hay, M. (1972), 'Notes on the growth and breeding of Acanthophis antarcticus', The Australian Herpetological Society Journal, 4 (4), pp. 14-15.

Hoser, R. T. (1981), 'Note on an unsuitable food item taken by a Death Adder (Acanthophis antarcticus)(Shaw)', Herpetofauna 13 (1), p. 31.

Hoser, R. T. (1982), 'Frequency of sloughing in captive Morelia, Liasis and Acanthophis (serpentes)', Herptile, 7 (3), pp. 20-26.

Hoser, R. T. (1983), 'Mating behaviour in Australian Death Adders, Genus Acanthophis (Serpentes Elapidae)', Herptile (8) 1, 1983, pp. 25-33.

Hoser, R. T. (1984a), 'Search for the Death Adder', Notes From NOAH, 11 (9), pp. 12-14.

Hoser, R. T. (1984b), 'Preferred activity temperatures of Nocturnal reptiles in the Sydney area', Herptile 9 (1), pp. 12-13.

Hoser, R. T. (1985a), 'Genetic composition of Death Adders (Acanthophis antarcticus: Serpentes: Elapidae) in the West Head area', Herptile, 10 (3), p. 96.

Hoser, R. T. (1985b) 'On Melanistic tendancies in Death Adders Acanthophis antarcticus (Shaw).' Litteratura Serpentium (English Edition), 5 (4), pp. 157-159.

Hoser, R. T. (1985c) 'On the question of immunity of snakes.', Litteratura Serpentium (English Edition), 5 (6), pp. 219-232.

Hoser, R. T. (1987), 'Notes on the Breeding of Death Adders (Acanthophis antarcticus)', Herptile, 12 (2), pp. 56-61.

Hoser, R. T. (1989), Australian Reptiles and Frogs, Pierson and Co., Sydney, NSW, Australia. 238 pp.

Hoser, R. T. (1991), Endangered Animals of Australia, Pierson and Co., Sydney, NSW, Australia. 240 pp.

Hoser, R. T. (1992), 'Search for the Ant-hill Python Bothrochilus perthensis (Stull, 1932)', Litteratura Serpentium, English Edition, 12 (1), pp. 13-19.

Hoser, R. T. (1993), Smuggled-The Underground Trade in Australia's Wildlife, Apollo Books, Moss Vale, NSW, Australia. 149 pp.

Hoser, R. T. (1996), Smuggled-2 - Wildlife Trafficking, Crime and Corruption in Australia, Kotabi Publishing,Doncaster,Victoria, Australia. 280 pp..

Hoser, R. T. and Williams, C. (1991), 'Snakes swallowing their own teeth', Herpetofauna, 21 (2), p. 33.

Hudson, P. (1979), 'On the breeding and birth of adders in captivity', Herpetofauna, 11 (1), 11-13.

Johnston, G. R. (1987), 'Reproduction and growth in captive Death Adders Acanthophis antarcticus (Squamata: Elapidae).' Transactions of the Royal Society of South Australia, 11 (1-2), pp. 123-125.

Mirtschin, P. J. (1976), 'Notes on breeding Death Adders in Captivity.', Herpetofauna, 13 (2), pp. 14-17.

Mirtschin, P. J. (1982), 'Further notes on breeding Death Adders (Acanthophis antarcticus) in captivity.' Herpetofauna, 13 (2), pp. 14-17.

Mirtschin, P. J. (1985), An overview of captive breeding of Common Death Adders Acanthophis antarcticus (Shaw) and it's role in conservation', in Grigg, G., Shine, R. and Ehmann, H. (eds), Biology of Australasian Frogs and Reptiles, Royal Zoological Society of New South Wales, pp. 505-509.

Mirtschin, P. and Davis, R. (1991), Revised Edition, Dangerous Snakes of Australia, Ure Smith Press, Sydney, NSW, Australia. 208 pp.

Mirtschin, P. and Davis, R. (1992), Snakes of Australia - Dangerous and Harmless, Hill of Content, Melbourne, Australia. 216 pp.

Shine, R. (1980), Ecology of the Australian Death Adder Acanthophis antarcticus (Elapidae): Evidence for convergence with the viperidae.' Herpetologica, 36 (4), pp. 281-289.

Shine, R. (1991), Australian Snakes - A Natural History, Reed Books, Sydney, NSW, Australia. 223 pp.

Stettler, P. H. (1985), Australian Death Adders - Remarks concerning the post-embryonic development of Acanthophis antarcticus (Shaw, 1794)', Litteratura Serpentium, English Edition, 5 (5), pp. 170-190.

Storr, G. M. (1981), 'The genus Acanthophis (Serpentes: Elapidae) in Western Australia.', Records of the Western Australian Museum, 9 (2), pp. 203-210.

Swan, G. (1990), A field guide to the Snakes and Lizards of New South Wales, Three Sisters Productions, Pty, Ltd, Winmalee, NSW, Australia, 224 pp.

van Woerkom, A. B. (1985), 'Postscript to the article "on the question of immunity of snakes", Litteratura Serpentium, English Edition, 5 (6), p. 233.

Wells, R. W. and Wellington, C. R. (1983), 'A synopsis of the class Reptilia in Australia', Australian Journal of Herpetology, 1 (3-4), pp. 73-129.

Wells, R. W. and Wellington, C. R. (1985), 'A classification of the Amphibia and Reptilia of Australia.', Australian Journal of Herpetology, Supplementary Series, (1), pp. 1-61.

Worrell, E. (1972), Dangerous snakes of Australia and New Guinea, Angus and Robertson, Sydney, Australia. 65 pp.

SLIDES AND CAPTIONS FOR DEATH ADDER ARTICLE.

There are 63 slides in total that went with this article. These are NOT reproduced here. To see most of these spectacular photos in full colour see the relevant issues of The Reptilian Magazine. All slides are by Raymond Hoser.

CAPTIONS.

1a/ Death Adder (A. antarcticus), male from Glenbrook, NSW. The specimen that bit author (see article). Note white end of tail, used in caudal luring.

1b/ Death Adder (A. antarcticus), male from Glenbrook, NSW. The specimen that bit author (see article).

1c/ Death Adder (A. antarcticus), male from Glenbrook, NSW. The specimen that bit author (see article). Note white end of tail used for caudal luring.

2a/ Death Adder (A. antarcticus), female from Terry Hills, NSW. Note black end of tail, used in caudal luring.

2b/ Death Adder (A. antarcticus), male from West Head, NSW.

2c/ Death Adder (A. antarcticus), male from West Head, NSW.

2d/ Death Adder (A. antarcticus), male from West Head, NSW.

2e/ Death Adder (A. antarcticus), male from West Head, NSW. with freshly sloughed skin.

3a/ Death Adder (A. antarcticus), male from West Head, NSW, prior to sloughing - note clouded eyes.

3b/ Death Adder (A. antarcticus), male from West Head, NSW, just after sloughing.

3c/ Death Adder (A. antarcticus), male from West Head, NSW, just after sloughing.

4/ Death Adder (A. antarcticus), female from Glenbrook, NSW with colour darkened markedly after a period in captivity.

5a-5c/ Death Adder (A. antarcticus), male from West Head, NSW.

6/ Death Adder (A. antarcticus), female from Port Pirrie, South Australia.

7/ Amelanistic Death Adder (A. antarcticus) from Gosford, NSW.

8a/ Barkly Tableland Adder, subadult from Anthony's Lagoon, NT.

8b/ Barkly Tableland Adder, juvenile from Anthony's Lagoon, NT..

9/ Death Adder (A. antarcticus), female from Dutchess, Qld. Note the large cyst on the snake's back.

10a-10b/ Death Adder (A. antarcticus), female from near Camooweal, Qld.

11a-12/ Northern Death Adder (A. praelongus), male from near Kunnanurra, WA. Note raised scale above the eye.

13/ Northern Death Adder (A. praelongus), female from Tully, Qld.

14a/ Northern Death Adder (A. praelongus), female from Weipa, Qld.

14b/ Northern Death Adders (A. praelongus), females. Grey from Tully, Qld, Red from Weipa, Qld.

15/ Desert Death Adder (A. pyrrhus), female, from The Tits, WA. Snake has just sloughed.

16/ Desert Death Adder (A. pyrrhus), female, from The Tits, WA. Just prior to sloughing. Note pinkish colour.

17/ Desert Death Adder (A. pyrrhus), male, from The Tits, WA. In flattened defensive posture which is typical of all Acanthophis.

18a-18b/ Desert Death Adder (A. pyrrhus), male, from Goldsworthy, WA. Note similarity of colour of snake to backround soil.

19/ Desert Death Adder (A. pyrrhus), male, from Goldsworthy, WA.

20/ Desert Death Adder (A. pyrrhus), male (roadkill). The white ventral surface typical of this species is an adaptation to minimise impact from crawling over very hot ground.

21a/ Habitat for Death Adder (A. antarcticus), West Head, NSW.

21b-21c/ Habitat for Death Adder (A. antarcticus), near West Head Road, Kurringai Chase Nat. Park, NSW.

22/ Habitat for Northern Death Adder (A. praelongus), north of Townsville, Qld.

23a/ Habitat for Northern Death Adder (A. praelongus), near Lake Argyle, WA. Note spinifex covering the hills.

23b/ Habitat for Northern Death Adder (A. praelongus), near Turkey Creek, WA. Note spinifex covering the hills.

24a/ Habitat for Desert Death Adder (A. pyrrhus), near Ayers Rock, NT. Spinifex is the dominant grass.

24b/ Habitat for Desert Death Adder (A. pyrrhus), near Devils Marbles, NT. Spinifex is the dominant grass.

25a/ Copulating Death Adders (A. antarcticus). Both from West Head, NSW.

25b/ Copulating Death Adders (A. antarcticus). Male from Glenbrook, NSW, Female from Terry Hills, NSW.

26a-26b/ Copulating Death Adders (A. antarcticus) from Glenbrook, NSW.

26c-26e/ Copulating Death Adders (A. antarcticus) from near Terry Hills, NSW.

26f/ Copulating Death Adders (A. antarcticus). Male from West Head, NSW. Female from Glenbrook, NSW.

27-31/ Printed as a series togeather/ Mating sequence for a pair of captive Death Adders (A. antarcticus). Male (red snake) commences by mounting female and aligns body with hers. This becomes less important later during mating. Female attempts to break off by crawling away and dragging male away with her by his hemipenis.

32/ Everted hemipenis of Death Adder (A. antarcticus) following breaking up of copulation. When shrunken, this organ rests inside the base of the snake's tail.

33/ Gravid Death Adder (A. antarcticus), from West Head, NSW. Note how scales on snake appear stretched. 34/ Death Adder (A. antarcticus) from West Head, NSW. giving birth.

35/ 20 new-born captive-bred Death Adders (A. antarcticus). All parents from Sydney region (NSW).

36/ Newborn Death Adder (A. antarcticus). (parents from West Head, NSW). Note slightly raised scale above eye.

37/ Captive Desert Death Adders (A. pyrrhus) eating and mating simultaneously. Both from The Tits, WA.