The inland taipan ( Oxyuranus microlepidotus ), also known as the fierce snake or small-scaled snake, is an elusive and highly venomous snake native to Australia. While often feared for its potent venom, which is considered the most toxic of any land snake, the inland taipan is a shy and reclusive creature, preferring to avoid conflict and rarely encountering humans.
Physical Characteristics and Identification
The inland taipan's body color shifts from dull olive green to dark brown or tan, depending on the season. This color change helps it regulate body temperature, with darker shades in winter to absorb warmth and lighter shades in summer to reflect heat. Many of the scales have darker edges forming indistinct bands especially towards the tail. The head may be black.
This Australian snake typically measures between 6 to 8 feet (1.8 to 2.5 meters) long, and its slender build allows for quick, stealthy movement. The head of the Inland Taipan is not distinct from the neck, as it is on Coastal Taipans. The body is streamlined. Average length for adults is about 2 meters (6.5 ft) with a maximum of about 2.7m (8.8 ft). Like other venomous snakes, it has sharp fangs that deliver extremely potent venom. Unlike other species with multiple defences, the inland taipan relies primarily on its powerful venom, a complex toxin that can paralyze muscles, cause internal bleeding, and lead to organ failure.
The only truly accurate way to identify most snakes is by counting the rows of scales across the back at mid-body and noting the pattern of scales on the head and tail.
Habitat and Distribution
Thriving in extremely remote and sandy regions of the Australian outback, the inland taipan is one of the world's most elusive snakes. Historically, its habitat has been in the Channel Country of southwest Queensland and northeastern South Australia. The inland taipan was once also active in northwestern Victoria, primarily around the Murray and Darling Rivers.
Read also: Comprehensive Guide to IE Weight Loss
In Queensland, the snake has been observed in Channel Country region (e.g., Diamantina National Park, Durrie Station, Morney Plains Station and Astrebla Downs National Park) and in South Australia it has been observed in the Marree-Innamincka NRM District (e.g., Goyder Lagoon Tirari Desert, Sturt Stony Desert, Coongie Lakes, Innamincka Regional Reserve and Oodnadatta).
The inland taipan thrives in Australia’s remote arid and semiarid regions, like the Channel Country, favoring clay plains with deep ground cracks to escape extreme heat. Unlike other venomous snakes that may be aquatic, the inland taipan is entirely terrestrial and perfectly adapted to the harsh Australian outback. Inland Taipans are associated with the deep cracking-clays and cracking-loams of the floodplains, however they also venture onto nearby gibber plains, dunes and rocky outcrops if cover is available. The vegetation in these areas is usually sparse, consisting of chenopod shrubs, lignum and the occasional eucalypt near the water channels. The snakes shelter in soil cracks and crevices, and in holes and mammal burrows.
Diet and Hunting Strategies
Primarily feeding on rodents, the inland taipan’s venom is perfectly suited to its prey, paralyzing and killing almost instantly, which minimizes injury risk during hunting. Its hunting efficiency gives it an edge over other predators.
The inland taipan is unique amongst Australia’s elapid snakes as the only species to feed exclusively on mammals. Inland Taipans feed on introduced mice, native rats, and small marsupials such as carnivorous Dasyurids. Long-haired Rats which go through large seasonal fluctuations are a primary prey item.
The inland taipan usually hunts during the early morning, but will remain active in the afternoon in cooler weather. Populations of plague rats fluctuate widely from year to year. The inland taipan adapts to these variations by becoming quite fat during years of abundance and losing weight or changing to different prey animals in years when plague rats are scarce.
Read also: The Hoxsey Diet
To detect prey, the inland taipan uses its tongue and Jacobson’s Organ, a sensory structure in the roof of its mouth that helps it pick up scents. They seem to have better eyesight than many other snakes. They flick their forked tongue rapidly in and out of the mouth, ‘tasting’ the presence on the air of potential prey animals. This chemical information is passed to the Jacobson’s organ in the roof of the mouth, and then to the brain. The lean muscular body allows the snake to travel fast in pursuit of its prey. When close enough, it corners the prey and bites it multiple times in rapid succession, delivering venom with each strike. Unlike other snakes that strike and release, the inland taipan holds onto its prey to prevent escape-its venom acts so quickly that there is minimal risk of injury to the snake. The snake corners the rat in its burrow or in a crack in the soil, then bites it quickly several times without releasing it. It may even grip the prey in a bend of its body (unlike the coastal taipan which strikes then releases its prey).
Now the snake is faced with its meal-usually a large rat-that may be several times larger in diameter than its own body. Snakes can’t rip their food apart, so they need to swallow their victim whole. First, they nudge the victim until it is correctly aligned so that they can swallow it headfirst. This way, they are not going against the grain of fur, feathers, or spikes on their prey. The two halves of a snake’s lower jaw are not fused in the middle, but are held together by flexible muscles and ligaments. This allows them to stretch incredibly far apart as the animal is swallowing. The upper and lower jaw do not ‘unhinge’ as is commonly believed. In order to move the food along, the snake grips it with the fangs on alternate sides of the jaw, moving one side of the jaw and then the other along the prey, passing it down its throat. The skin of the snake is also very stretchy, with relatively small scales.
After eating large prey, the snake will usually spend much time basking in the sun to maintain a high enough body temperature to digest the meal. The ability to swallow very large food items means that a big snake need not expend energy on frequent hunting activities.
The Inland Taipan's Deadly Venom
The inland taipan’s venom is one of the most potent in the world, targeting the nervous and circulatory systems to paralyze and kill its prey. It also contains an enzyme that accelerates absorption, ensuring the venom spreads rapidly through the prey’s body.
The venom of the inland taipan is by far the most potent venom of any land snake in the world. The venom is actually a powerful cocktail of enzymes and other agents that paralyse nerve endings, destroy muscle tissue and cause severe bleeding. The accepted standard for comparing the toxicity of snake venoms was devised in the 1970s by the Commonwealth Serum Laboratory (CSL) in Melbourne. Tests were done by injecting live mice and measuring the amount of venom required to kill 50% of test animals, yielding a number called LD50 (or Lethal Dose 50): the smaller the number, the more toxic the venom. The LD50 of the Inland Taipan is 0.025mg/kg. Expressed in other units, a single bite could kill nearly 250,000 mice. Inland taipans have shorter fangs (from 3.5 to 6.2mm long, or about ¼ of an inch) than coastal taipans, and inject only about 1/3 as much venom per bite.
Read also: Walnut Keto Guide
Inland taipan snake venom contains potent presynaptic neurotoxins (toxins in venom that cause paralysis or muscle weakness). Also present are postsynaptic neurotoxins, which are less potent, but more rapidly acting than the presynaptic neurotoxins. Presynaptic neurotoxins disrupt neurotransmitter release from the axon terminal. This takes days to resolve and does not respond to antivenom. Postsynaptic neurotoxins competitively block acetylcholine receptors, but the effect can be reversed by antivenom. Envenoming causes a progressive descending flaccid paralysis; ptosis is usually the first sign, then facial (dysarthria) and bulbar involvement occur, progressing to dyspnea and respiratory paralysis leading to suffocation and peripheral weakness. Because it can act so fast, it can kill a person within about 45 minutes. People experiencing effects of the venom within half an hour have been reported.
The venom also contains a potent hemotoxin (procoagulants), a prothrombin activator that leads to the consumption of major coagulation factors, including fibrinogen, leading to interference with blood clotting. This causes defibrination, with nonclottable blood, putting victims at risk of major bleeding from the bite site and can lead to more serious, sometimes fatal, internal haemorrhaging, especially in the brain. Taipan snake venom does contain myotoxins that cause myolysis (rhabdomyolysis, muscle damage); the urine of bite victims often turns reddish-brown as their muscles release myoglobin, which is passed through the kidneys (myoglobinuria).
Mating Habits
Breeding occurs in late spring to early summer (October to December). Like coastal taipans, male inland taipans may engage in a spectacular competitive display called ritualistic combat. In this test of strength, they wrap around each other’s bodies like a coiled rope, wrestling with each other till the stronger snake forces his rival’s head to the ground. The struggle may last for hours, until the stronger male finally wins the right to mate with the female. If the female is receptive, he rubs his chin up and down her body, then twists the lower part of his body under hers. Males have two sex organs, called hemipenes, but only one at a time is used for mating. Mating may last for several hours, and a female may mate with more than one male during the breeding season.
About two months after mating, the female lays up to 20 eggs, with an average clutch size of 16 eggs. Older females (which have a larger body size) generally lay more eggs than younger ones. Taipan eggs are elongated in shape, with a leathery, permeable shell. Females will not usually mate every year because of the high energy costs and risks associated with reproduction. After depositing her eggs, the female abandons the nest site. Young snakes grow very fast under favorable conditions. Males and females grow to about the same size.
Conservation Status and Human Interaction
Though one of the world’s most venomous snakes, the inland taipan is rarely encountered by humans due to its remote habitat, and bites are extremely rare. Antivenom is available, but symptoms from a bite are severe, including nausea, vomiting, and high blood pressure. All Australian hospitals and medical clinics carry specific antivenes, as well as kits that enable the staff to identify the type of snake by taking a swab of the bite site. It is not necessary to kill or capture the snake in order to identify it. You are just putting yourself at added risk of being bitten.
The inland taipan is common within its range and is not considered endangered. However, this species has disappeared from parts of its historic range, likely including NSW, however is currently classed as Least Concern. As mammal-specialists, taipans have been less affected by the spread of poisonous Cane Toads across Australia than other snakes. Their specialisation in mammals however makes them dependent on prey availability, which has been reduced in areas by cats and foxes. They have also been assessed as highly vulnerable to the future impacts of climate change on the Australian landscape.
Despite its powerful abilities, the inland taipan is extremely shy around humans and other large animals, preferring to flee rather than engage. So long as a person is not creating much vibration and noise, the inland taipan may not feel alarmed or bothered by a human presence. However, caution should be exercised and a safe distance maintained as it can inflict a potentially fatal bite. The inland taipan will defend itself and strike if provoked, mishandled, or prevented from escaping. Firstly, but not always, it makes a threat display by raising its forebody in a tight low S-shaped curve with its head facing the threat.