Coastal Taipan

Coastal Taipan
Conservation status
Least Concern (IUCN 2.3)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Vertebrata
Class:	Reptilia
Order:	Squamata
Suborder:	Serpentes
Family:	Elapidae
Genus:	Oxyuranus
Species:	O. scutellatus
Binomial name
Oxyuranus scutellatus Peters, 1867[2]

The Coastal Taipan (Oxyuranus scutellatus), or common taipan,^[3] is a large, highly venomous snake of the family Elapidae.^[1] It is native to the coastal regions of northern and eastern Australia and the island of New Guinea. According to most LD₅₀ studies, this species is the third most venomous land snake in the world.^[4][5]

Physical description

A coastal taipan.

Coastal taipans are large snakes. It is the largest venomous snake in Australia.^[6] Adult specimens of this species typically grow to lengths of 2 to 2.5 meters (6.6 to 8.2 ft) on average and slightly larger specimens are relatively common.^[7][8] Although rare, a maximum length of 3.3 metres (11 ft) is attainable by this species. According to the Queensland Museum, the longest recorded length for the coastal taipan as recorded in Australian museum collections is 2.9 metres (9.5 ft) and weighed 6.5 kilograms (14 lb).^[6] The head of this species is long, narrow and big like that of the African Black mamba. In fact, in several aspects of morphology, ecology and behavior, the Coastal taipan is strongly convergent with the black mamba (Dendroaspis polylepis).^[9][7] It has an angular brow and is lighter coloured on the face. The body is slender, yet strong and sturdy and colouration can vary.^[8] They are often uniformly light olive or reddish-brown in colour, but some specimens may be dark gray to black. Their colouration gets lighter on the side of their bodies and their ventral side (the belly) is usually a creamy-white to a pale light yellow in colour and is often marked with orange or pink flecks. The eyes are round, big and are light brown or even hazel in colour with big pupils.^[8][7][10]

Scalation

Dorsal scales at mid-body 21-23, ventrals 220-250, subcaudals 45-80, subcaudals are divided, anal plate is single, temporales 2+3 (3+4).^[7]

Geographical range and habitat

Coastal taipans occur only in Australia and the island of New Guinea, which comprises of two Indonesian provinces on the west side of the island and the nation of Papua New Guinea is on the east side of the island.^[7] The Australian subspecies (Oxyuranus scutellatus scutellatus) is found in the coastal regions of Queensland and in the northern parts of the Northern Territory and the northeastern parts of Western Australia. The southern most part of this subspecies' range is the most northern tip of New South Wales bordering Queensland. Coastal taipans do not live anywhere where the maximum winter temperature is only 20 °C (68 °F).^[11][8] The second subspecies (Oxyuranus scutellatus canni) is found throughout the island of New Guinea, with higher concentrations of the snake being found in the nation of Papua New Guinea.^[12]

Habitat

Coastal taipans can be found in a variety of different habitats. They can be found in warm wetter temperate to tropical coastal regions, in monsoon forest, wet and dry sclerophyll forest and woodland, and in natural and artificial grassy areas including grazing paddocks, and disused rubbish tips.^[13][12] In Queensland, they have adapted well to sugarcane fields where they thrive on the rodent population in the fields. In Far North Queensland in the Cape York Peninsula, they are usually found in open woodland areas.^[8] Thickets of introduced lantana are also favoured habitat. The Coastal taipan shelters in abandoned animal burrows, hollow logs and in piles of vegetation and litter.^[13]

Behavior and diet

The Coastal taipan is primarily diurnal, being mostly active in the early to mid-morning period, although they may become nocturnal in hot weather conditions. When hunting, it appears to actively scan for prey using its well-developed eyesight, and is often seen travelling with its head raised slightly above ground level. Once prey is detected the snake ‘freezes’ before hurling itself forward and issuing several quick bites. The prey is released and allowed to stagger away - this strategy minimizes the snake’s chance of being harmed in retaliation, particularly by rats which can inflict lethal damage with their long incisors and claws.^[14] It is not a confrontational snake and will seek to escape any threat. However, when cornered it can become very aggressive and may strike repeatedly.^[13]

Diet

These snakes feed solely on warm-blooded animals such as mammals and birds. Rats, mice, bandicoots, and various species of birds make up their entire diet.^[13]

Venom

This snake is the world's third most venomous snake. The SC LD₅₀ of this species is 0.106 mg/kg^[5] and the average venom yield per bite is 120 mg, with a maximum yield of 400 mg. When the Coastal taipan strikes it injects a large amount of highly toxic venom deep into the flesh, and similar to the Black mamba, studies have shown they are capable of injecting the same amount of venom in a second or third bite. Its venom contains primarily taicatoxin, a highly potent neurotoxin and are known to cause hemolytic and coagulopathic reactions.^[15] Death can occur as early as 30 minutes after being bitten, but average death time after a bite is around 90 minutes and it may even take up to 6-8 hours depending on the nature of the bite.^[15] Untreated bites have a mortality rate that is close to 100%, second only to the Black mamba.^[15][16]

Subspecies

Subspecies[17]	Taxon author[17]	Common name	Geographic range
Oxyuranus scutellatus canni	(Slater, 1956)	Papuan Taipan	Throughout the island of New Guinea[12]
Oxyuranus scutellatus scutellatus	(Peters, 1867)	Coastal Taipan	Australia: coastal Queensland, northern parts of Northern Territory and the northeastern parts of Western Australia[11]

External links

• Barnett, Brian. "Keeping and Breeding the Coastal Taipan (Oxyuranus scutellatus)." Journal of the Victorian Herpetological Society, 10 (2/3), 1999 (pages 38–45).
• Williams, David. "The Death of Kevin Budden." David Williams' Australian Herpetology Online, January 2004.

References

1. ^ ^{a b} Queensland Government - Environment and Resource Management (Oxyuranus scutellatus)
2. ^ [www.reptile-database.org The Reptile Database.]
3. ^ CSL Antivenom Handbook
4. ^ Zug, George R. (1996). Snakes in Question: The Smithsonian Answer Book. Washington D.C., USA: Smithsonian Institution Scholarly Press. ISBN 1560986484. 
5. ^ ^{a b} LD50 Menu (Dr. Bryan Grieg Fry)
6. ^ ^{a b} Australian Venom Research Unit
7. ^ ^{a b c d e} DEVENOMIZED (Coastal Taipan)
8. ^ ^{a b c d e} Queensland Museum (Coastal Taipan Information)
9. ^ Shine, Richard; Covacevich, Jeanette. (March 1983). "A Ecology of Highly Venomous Snakes: the Australian Genus Oxyuranus (Elapidae)". Journal of Herpetology 17 (1): 60–69. http://links.jstor.org/sici?sici=0022-1511(198303)17:1%3C60:EOHVST%3E2.0.CO;2. 
10. ^ Hoser, R.T. (May 2002). "AN OVERVIEW OF THE TAIPANS, GENUS (OXYURANUS) (SERPENTES:ELAPIDAE) INCLUDING THE DESCRIPTION OF A NEW SUBSPECIES.". Crocodilian - Journal of the Victorian Association of Amateur Herpetologists 3 (1): 43–50. 
11. ^ ^{a b} Shine, R.; Covacevich, J. (1983). "Ecology of highly venomous snakes: the Australian genus Oxyuranus (Elapidae).". Journal of Herpetology 17: 60–69. 
12. ^ ^{a b c} A Guide to the Snakes of Papua New Guinea. Port Mosby, Papua New Guinea: Independent Publishing Group. 1996. pp. 251. ISBN 9810078366. 
13. ^ ^{a b c d} Australian Museum (Coastal Taipan)
14. ^ A Complete Guide to the Reptiles of Australia. Australia: New Holland Publishers Pty Ltd. 2011. pp. 558. ISBN 13: 9781877069765. 
15. ^ ^{a b c} "IMMEDIATE FIRST AID for bites by Australian Taipan or Common Taipan". http://drdavidson.ucsd.edu/Portals/0/snake/Oxyura~2.htm. 
16. ^ Coastal taipan mortality rate
17. ^ ^{a b} ITIS