Frequently Asked Questions About Snakes

Which is the largest snake in the world?

Either the Anaconda (Eunectes murinus) from South America or the Reticulated Python (Python reticulatus) from South-East Asia. The Anaconda grows to 9.5 m and can weigh round 200 kg. The Reticulated Python grows to 10.1 m but, being of slender build, weighs less (Queensland Museum, sourced February 2007, http://www.qm.qld.gov.au).

Which is the largest snake in Australia?

The Amethystine (Scrub) Python (Morelia kinghorni, formerly M. amethistina), from North Queensland. The largest specimen reliably measured had a total length of 5.65 metres. Specimens longer than this have been reported frequently, but these records cannot be authenticated. Greer (1997) records the maximum range as 4.30 - 5.77metres.

Which is the largest venomous snake in Australia?

The longest of our venomous snakes is the Coastal Taipan (Oxyuranus scutellatus), which may grow up to 3.3 metres, but averages about 2.5 metres in length. (NB: According to the Queensland Museum, the longest recorded length for the Coastal Taipan in Australian Museum collections is 2.9 metres). This snake weighed 6.2 kgs. The Mulga Snake (Pseudechis australis) is close behind, said to be able to grow up to 3 metres, but it averages about 1.5 metres. Where the Mulga Snake wins is that it is the heaviest of our venomous snakes.

Which is potentially the most dangerous (venomous) snake in Australia?

This is a vexed but commonly asked question for which there is no satisfactory answer. This is because there are so many variables to be considered. The Queensland Museum has probably approached it best by suggesting five factors should be taken into account: venom toxicity, venom yield, fang length, temperament of the species and frequency of people bitten. However, the aspect of this which is controversial is venom toxicity. The LD 50 (lethal dose 50%) which is the measure of lethality, varies depending upon the type of animal it is tested in, route of injection and the way venom is prepared for injection. Most venoms are far more potent injected into a vein rather than under the skin which is more likely to be how most bites occur. But if results of experiments into lethality are obtained using the intravenous route they cannot easily be compared with others that have been obtained if the method is not the same. The Coastal Taipan (Oxyuranus scutellatus), is usually accepted as Australia's most dangerous venomous snake. To complicate matters further it should also be remembered that large pythons are also very dangerous and a fatality occurred in Australia in 2005. Any python over about 3 to 4 metres must be viewed as potentially dangerous as they have the size and strength to incapacitate an adult human within several minutes by pinning their arms to the body and constricting the person's chest so that they cannot breathe. None of our venomous snakes could kill a human as quickly (Clinical Toxinology website www.toxinology.com and Queensland Museum, sourced February 2007, http://www.qm.qld.gov.au). If you would like to know more 'Ask Living with Wildlife'

What is anti-venom?

Anti-venom is the substance that you are given to counteract the effects of envenomation. Snake anti-venoms are made by collecting venom from a species of snake, sterilising and purifying it, then injecting a sublethal dose into a horse, increasing the dosage over time. This stimulates the production of antibodies to that type of snake's venom. Serum is collected from the horse and treated to produce the specific (monovalent) anti-venom. There are five types of anti-venom: brown, black, tiger, death adder and taipan, plus a "broad spectrum" polyvalent anti-venom for any Australian snake. When the anti-venom is administered in a hospital with intensive care facilities (required to counter any adverse affects such as an anaphylactic reaction to the anti-venom - rare but possible), the antibodies attach to molecules in the circulating venom in a patient's body, rendering them harmless (CSL Biosciences & Australian Venom research Unit 2007).

Why do we say some snakes are venomous and not poisonous?

The simple answer is that venom is injected (for example, through fangs) and poison is inhaled or ingested (for example, by swallowing a chemical). If snakes were poisonous, we wouldn't be able to eat them. Venomous snakes are generally classified into four taxonomic families: Elapids, Viperids, Colubrids & Atractaspidae. Venomous snakes use their venom primarily to immobilise their prey and for predigestion, and to a lesser extent in self-defense (Wikipedia, sourced February 2007, http://en.wikipedia.org/wiki/Elapid).

What is venom? What is it for?

Snake venom is a complex 'cocktail' of chemicals. The components of venoms and their effects vary between species of snakes and other variables. Some venoms affect nerves (neurotoxins), some break down blood vessels (haemotoxins), others affect muscle tissue (myotoxins). Venoms of some Australian snakes are mainly neurotoxic, causing muscle paralysis, respiratory failure, nausea, vomiting and diarrhoea (Queensland Museum, sourced February 2007, http://www.qm.qld.gov.au).

Do pythons crush their prey?

No. A python will whip its body coils round its prey, constricting and progressively suffocating its victim. Constriction may also collapse the chest cavity, deflate the lungs and compress the heart (Queensland Museum, sourced February 2007, http://www.qm.qld.gov.au).

What do Australian snakes eat?

Many feed on small vertebrates. Lizards are the primary prey of many Australian snake species. Frogs, birds and small mammals are also commonly preyed upon. Some snakes have highly specialised diets. Among these are the blind snakes (Ramphotyphlops spp.), which prey on termites and the eggs, pupae and larvae of ants; the White-bellied Mangrove Snake (Fordonia leucobalia), a crab eater; the Turtle-headed Sea Snake (Emydocephalus annulatus), which preys solely on gobiid fish eggs; and the Bandy Bandy (Vermicella annulata), which eats only blind snakes (Queensland Museum, sourced February 2007, http://www.qm.qld.gov.au).

Is it true that if I have lizards in my garden then I don't have snakes?

No! Lizards are the primary prey for many Australian snakes. (Queensland Museum, sourced February 2007, http://www.qm.qld.gov.au).

Why, how, and how often do snakes shed their skins?

Snakes, and all other reptiles, must shed their skins to accommodate growth. A snake will often shed its skin in one piece. Once a new layer of skin has formed below the old one, a chemical is secreted to separate the two layers. The snake may become sluggish and its skin becomes dull and opaque for a period of time. Then the snake begins to rub its snout against something rough, like a rock or log. The old skin, including the clear 'spectacles' that cover the eyes, peels back from the lips and slowly turns inside-out, along the full length of the body and tail. The fresh skin is shiny. Young snakes grow quickly and shed frequently. Large, adult snakes grow more slowly, and shed less but it is not possible to be specific about how often they shed their skin. The rate of shedding varies with the availability of prey. All snakes shed their skins following an injury, probably to hasten healing (Queensland Museum, sourced February 2007, http://www.qm.qld.gov.au).

How far can snakes live from where they shed their skin?

Snakes shed their skin anywhere within their home range, which varies between different species, sizes of snakes and sex (Queensland Museum, sourced February 2007, http://www.qm.qld.gov.au).

Do snakes come out at night?

Yes! During very hot weather snakes which are normally active during the day may delay hunting until the environment starts to cool in the evening. Others may naturally be more active at sunset (crepuscular) or after night fall.

How long can snakes hold their breath underwater for?

Black snakes are able to hold their breath underwater in excess of half an hour (personal observation of Geoff Coombe). The length of time brown snakes can hold their breath is unknown. Sea snakes can hold their breath for 90 minutes!

Can snakes bite underwater?

Yes! A fatality from a Brown Snake bite in 1992 occurred when the person attempted to kill the snake in water, possibly believing that they cannot bite when their mouth is in water (Research by Geoff Coombe).

How many young can a snake give birth to at a time?

It depends upon species, size of the female snake, her health and whether it is an egg-layer or live-bearer. Australian elapid snakes can give birth from one to 38 individuals (Greer 1997).

If there is a snake in my garden can I get rid of it?

If there is a snake in your garden do not attempt to touch it. Almost all snake bites occur when people try to handle, kill or harm the snake. Most snakes will leave the area on their own accord after a short time. Snakes will avoid people but they can pose a risk to people and pets who encounter them. Untrained persons should never attempt to touch or catch a snake. The incidence of snake bites in South Australia is low because snakes are generally shy by nature. Most snake bites can be attributed to the Eastern Brown Snake. This species has adapted well to human habitation, so is more likely to come into contact with people. Red-bellied Black Snakes can be found in wetland areas and Tiger Snakes occur in a limited area in the hills but these species tend to avoid people and houses so are not normally in conflict. To minimise the chance of snakes in the garden,clean up rubbish around the home and keep the garden tidy. Take steps to reduce mice and rats which the snakes will hunt for food. Wear solid shoes and trousers when gardening. Check boots before putting them on if left outdoors, and never put hands somewhere that cannot be seen. It is advisable to know the first aid necessary to deal with a bite (Wildlife Preservation Society of Queensland, sourced February 2007, http://www.wildlife.org.au/index.htm).

If you're out camping and you get bitten by a venomous snake, what should you do?

The first thing you should do is keep as still as possible. If there is the slightest suggestion that a person has been bitten they MUST commence first aid immediately. DO NOT delay to see if there are going to be any symptoms. Remove any jewellery and do not interfere with the bitten area in any way. Apply a crepe bandage (or similar material), starting at the extremity then bandage up the arm or leg, nice and firm just like you would for a sprain. Immobilise the bitten limb with anything comfortable. It has been determined in recent years that immobilisation is critically important for survival after a venomous snake bite. Keep as calm as possible, stay still and call an ambulance or the royal flying doctor service if in a rural area (Australia Zoo, sourced February 2007, http://www.australiazoo.com.au).

How do you know when a snake has reached sexual maturity?

Reptiles become sexually mature by size, not by age and their size is dependent on temperature and availability of food (Australia Zoo, sourced February 2007, http://www.australiazoo.com.au).

Are snakes good for anything?

Snakes are good and valued by many! Wherever they occur, snakes are an integral part of the environment. As predators, snakes eat pests such as mice and rats. As prey, they are food to many species of animals, such as goannas, crocodiles, kookaburras, birds of prey and quolls. Venom from many snakes of the world have been used to treat numerous human disorders. Some examples include, antihypertensives to prevent blood clots, for diagnosis of certain diseases; while others may have analgesic activity to treat pain or have the capacity to destroy tumour cells. Two lines of current research involve compounds of social and or economic value (Menez 2003). For most people, a richly diverse natural world, which includes snakes, is vastly more interesting than the alternative (Queensland Museum, sourced February 2007, http://www.qm.qld.gov.au).

If I want to keep reptiles, do I need a permit?

Under South Australian legislation all native reptiles are protected and a permit is required to keep most species. It is illegal to keep exotic (non-Australian) reptiles. A reptile is a long term commitment. Turtles can live for more than 30 years, pythons for more than 15 years and lizards such as Bluetongues for 20 years. It is illegal to take reptiles animals from the wild. All lizards, snakes and turtles are protected under the National Parks and Wildlife Act 1972. You can apply for a permit from the Fauna Permits Unit in the Department for Environment and Heritage to keep captive-bred reptiles as pets. Poor ventilation and inappropriate environment (heat, cold, light) together with inappropriate tank size or poor handling techniques can all cause unacceptable levels of stress for reptiles. Any person considering keeping a reptile for the first time should seek advice from a group such as the SA Herpetology Group or an experienced reptile keeper. This will ensure that the facilities are appropriate and the prospective keeper knows the food and other requirements of the species they intend to keep. (Department for Environment and Heritage South Australia, sourced February 2007, http://www.environment.sa.gov.au).

References

• Clinical Toxinology Resources. Website: www.toxinology.com
• CSL Biosciences (undated). Snake Venom Detection Kit Technical Information. CSL Biosciences
• Greene, Harry W. (1997). Snakes. The Evolution of Mystery in Nature. University of California Press
• Greer, Allen (1997). The Biology and Evolution of Australian Snakes. Surrey Beatty & Sons Pty Ltd
• Menez, Andre (2003). The Subtle Beast. Snakes, from Myth to Medicine. Taylor & Francis

Other useful references include:

• Judd, Mark & White, Julian (1994). A South Australian Handbook on Bites and Stings. South Australian Museum and Women's and Children's Hospital, Adelaide
• Shine, Rick (1993). Australian Snakes. A Natural History. Reed
• Carl H. Ernst & George R. Zug (1996). Snakes in Question. CSIRO Publishing
• Thomson, Bruce (2004). Australia's Most Deadly and Dangerous Beasts. Thomas C. Lothian Pty Ltd

The content of this page was created by the Mount Pleasant Natural Resource Centre in collaboration with Living with Wildlife (2007)