The Taipan is a very venomous, moderately aggressive snake. There are two species of Taipan in Australia – the Inland Taipan and the Common Taipan. A third, the Papuan Taipan, is found in Papua New Guinea. Until the development of an antivenom in 1955, over 90% of bites were fatal.
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Elapidae
Genus: Oxyuranus
The Taipan genus (
Oxyuranus) is represented by two
Australian taipan
species, and a
Papuan taipan. The three taipan species share much in common. Their
feeding strategy is almost identical, as is the action of their
venom.
The taipan preys exclusively on small mammals – generally rat and mouse species. It is diurnal, and generally most active in the morning. In order to maintain its specialised diet, the taipan has developed an extremely potent venom, along with fearsome speed and a ‘snap and release’ multiple bite that minimises the risk of injury to the snake by struggling prey items.
Part of the reason for the taipan’s fearsome reputation is the dual nature of the venom. Snake venom in general works in one of two ways – either by attacking the nerve centres (neurotoxicity) or by coagulating the blood (coagulopathy). The taipan venom does both – so the old tiger snake antivenom did not work on taipan bite victims. Fortunately, an antivenom was developed in 1955, and there have been no recorded fatalities in Australia since then. The antivenom developed for the coastal taipan is effective against bites from both the inland and the Papuan species.
Egg clutch size varies between the species. The eggs are oval, and around 5 cm in length, weighing about 30 grams. The incubation period ranges from 55 to 65 days, and the young are around 30 – 40 cm long at birth.
Coastal Taipan (
Oxyuranus scutellatus) also
Eastern Taipan,
Common Taipan,
Australian Taipan.
Found along coastal and somewhat inland areas of the Northern Territory and Queensland, also in northern Western Australia. It has occasionally been found along coastal New South Wales. It is the longest venomous Australian snake: growing up to three metres in length. The body of the adult is brown or tan (occasionally black or olive), with a yellow or cream underside, and lighter head. Due to its mammalian diet, it is attracted to human habitations, and may live under pieces of tin and other debris near to farmland. It is capable of very fast movement – reports from cane workers in the 1950’s talk about a snake moving faster than a horse can run. This may very likely be exaggeration – as the cane workers were scared witless by the taipan, which enjoyed a rather awesome reputation at the time.
The coastal taipan produces clutches of about 10 – 20 eggs. Eggs are laid in a shallow depression in sand or gravel.
The average venom yield of the coastal taipan is around 120mg, with a recorded maximum yield of 400mg. The LD50 (dose that was fatal for 50% of victims) is 0.064 mg/kg of body weight.
Inland Taipan (Oxyuranus microlepidotus) also Fierce Snake, Small Scaled Snake.
This rare relative of the coastal taipan is found in a limited range in western inland Queensland, though its range may spill over into inland Northern Territory and even New South Wales. It grows to about 1.7 metres on average, with 2 metre specimens occasionally recorded. It is generally a lighter colour than the coastal taipan, though with a similar body shape, and the head may frequently be black. A seasonal change in colouring has been noted – with a darker winter colour and a light summer colour. Unlike the coastal taipan, it has no human habitations to frequent, and may actually live in rat burrows. Due to its rarity, little is known about the behaviour of this snake in the wild. Despite the name, this snake is not unduly aggressive. Until 1974, the inland taipan was virtually unknown to science. It was first described in 1879, but live specimens were not obtained until the ‘70s. The rarity of the inland taipan, combined with its remote habitat, has undoubtedly contributed to the fact that no deaths have been recorded, and the only recorded bites have been suffered by herpetologists.
The inland taipan produces clutches of about 9 – 12 eggs.
The average venom yield of the inland taipan is 44mg, with a maximum yield recorded of 110mg. The venom of the fierce snake is the most toxic of any snake worldwide. It is almost five times more deadly, weight for weight, than the coastal taipan venom, with an LD50 of 0.010 mg/kg body weight.
Papuan Taipan (Oxyuranus scutellatus cann)
Found in Papua New Guinea and Irian Jaya, the Papuan taipan is a close relative of the Australian coastal taipan. Its venom is slightly more toxic than that of the coastal taipan, with an LD50 of 0.050 mg/kg body weight. Like the coastal taipan, it lives near human habitations. It is said to account for around 82% of snake bites in the Central Province of Papua New Guinea. Due to the poor medical facilities and lack of antivenom supplies, a Papuan taipan bite is still a very serious medical emergency – with about 50% of victims requiring mechanical ventilation.
Acknowledgements:
http://www.smuggled.com/BriBar17.htm
http://www.kingsnake.com/
http://www.avru.unimelb.edu.au/avruweb/Taipans.htm
http://www.reptilepark.com.au
"Australian Snake Man" by Roy Norry, published by Thomas Nelson Pty Ltd, Sydney, 1977.