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When I think of countries with deadly animals, Australia is usually the first place that comes to mind. This massive island nation contains creatures that many people would consider to be the stuff of nightmares! A lot of this is to do with the creatures that were left here when the continents split and how they evolved.
Deadliest Creatures in Australia
Australia is home to some amazing animals, but many of them pose significant dangers to humans. If you ever visit this wonderful country, keep your eyes and ears open for some of the following dangerous animals!
1. Saltwater Crocodile (Crocodylus porosus)
The saltwater crocodile is a huge reptile. In fact, it’s the largest on the planet, and males can weigh more than a 4,400 lbs (2,000 kg) and measure up to 23 feet (7 meters)! While there were rumors of an individual growing to 28 feet (8.5 meters) in length, this is not confirmed. Not only are they enormous, but these crocs have a powerful bite of more than 3,700 pounds per square inch (psi) that easily crushes bones!
Saltwater crocodile is a pretty misleading name as they’re not only found in saltwater but freshwater as well and they’re found all over the Northern Territory and in Queensland. Sadly, these animals are classed as vulnerable, with between 100,000 and 200,000 in the wild. They are hunted for their meat and skin, and in some areas culls even take place. However, the Australian government has not only protected the species but also has programs to research and monitor the crocs as well as limiting their contact with humans.
What’s terrifying about them is how territorial they can be, not to mention the fact that they’re opportunistic hunters who can even turn cannibalistic. In the Northern Territory, human and crocodile conflict is common especially because this is such an aggressive species. However, while attacks on humans do happen, they only result in around 2 fatalities each year.
When hunting, they’ll often remain underwater and can submerge for two hours without the need to surface for breath. What’s more, their eyesight is impeccable, allowing them to spot prey both above and below the surface.
But while saltwater crocodiles are a threat to humans, they have been seen as an important symbol to the Aboriginal people of Australia. That said, most people want to avoid meeting one, so it’s best to observe warning signs and avoid swimming in areas where crocs are known to live.
In the event that you do come face to face with one, it’s advised to stay well back and avoid disturbing the animal. If this fails and the crocodile tries to attack, the best form of defense is to fight back, aiming particularly for the animal’s snout and eyes.
2. Sydney Funnel-Web Spider (Atrax robustus)
The Sydney funnel-web spider is one of the most aggressive and territorial species of spider in Australia. It won’t think twice about biting to defend its nest and, when left untreated a bite can be fatal, with death occurring in as little as 15 minutes.
However, there is an antivenom created by milking the spiders of their venom, and this happens at the Australian Reptile Park in Sydney. But if you want to survive a bite, then it’s essential that you seek medical attention as a matter of urgency.
The reason that these spiders are so toxic is that their venom contains a neurotoxin called delta-hexotoxin, which attacks the nervous system, stopping victims from being able to breathe. But the good news is that it’s really only the males that can deliver a potentially fatal bite due to their larger fangs. But there have still only been 13 recorded deaths. During mating season, between November and April, it’s more common to see the males as they go in search of a mate.
These are large spiders found along the east coast of the country in wet habitats like swamps but are also commonly found in the garden. Females can have a body length of up to 2 inches (50 mm). They take their name from the fact that they build a funnel-shaped web, and you’ll probably notice that they become more active in summer.
Despite being feared, the funnel-web is actually protected in Australia, making it a criminal offense to harm or trap them. Of course, if you find one in your property, you won’t want to share the space with it, so it’s important to call a pest controller for help.
Of course, prevention is better than cure, so keeping your yard tidy and free from potential hiding spots is a must. What’s more, when you’re out in the yard, wearing protective gear could provide enough of a barrier against a bite.
3. Box Jellyfish (Chironex fleckeri)
Sometimes called the sea wasp because of its deadly venom, the box jellyfish is one of the most feared sea creatures in Australia. They’re found around the coasts, primarily in the northern part of the country and prefer shallow waters, which makes them a threat to beachgoers and swimmers. Box jellyfish are most active between October and April, when signs around the beach will warn you about the dangers of entering the water.
The venom of the box jellyfish contains cnidarian toxins that are incredibly potent and have the potential to kill a human in minutes, although in some cases, a phenomenon called irukandji syndrome can make the suffering last for up to 48 hours. The sting is delivered in the blink of an eye, and thanks to the barbed tentacles, the delivery of the venom is extremely painful. What’s more, any stinging cells left inside can continue to pump venom into your body.
In the main, most people survive box jellyfish stings, but fatalities may experience cardiac arrest. One of the most recent deaths was that of a 14 year old boy visiting Australia from the Philippines.
These jellyfish are not overly large but have very long tentacles that are attached to each corner of its box-like bell. If you happen to have some vinegar to hand, then it’s recommended to apply this as a first line of treatment, as the acid is known to counteract the venom. That said, in any case, a box jelly sting should be considered a medical emergency.
In order to avoid being stung by a box jelly, it is vital to pay heed to the beach signs. In some locations, stinger nets have been installed to stop these creatures making contact with humans. But if you do go into the water, wearing a wetsuit or other such protective clothing can prevent contact with the tentacles. What’s more, it’s worth noting that the number of box jellyfish reported around the Australian coast has declined in recent years and this is thought to be due to the effects of climate change. However, reports also indicate that while numbers may be lower, the habitat of this species has spread due to rising temperatures.
Box jellyfish are a threat to humans, but scientists are performing research on how their venom may be used in medicine, particularly for the treatment of heart disease. Further research is taking place that looks at the life cycle of these creatures so that we can come up with new ways to prevent stings.
4. Eastern Brown Snake (Pseudonaja textilis)
I’ll always remember watching one of Steve Irwin’s TV episodes in which he discussed the dangers of the brown snake. While this snake may look unremarkable with its brown body that sometimes contains black rings, it’s actually one of the most venomous snakes in the world.
Eastern brown snakes, as their name suggests are distributed along the eastern side of Australia and into the center of the country. The problem is that they often come into contact with humans, especially in rural areas. They’re also responsible for a large number of wildlife related deaths, killing 23 people between 2000 and 2016 alone.
So, what is in that venom that makes it cause respiratory failure, bleeding, paralysis, and potentially death? There are two main toxins called taipoxin and textilotoxin found in this venom and if you’re bitten, it’s vital to apply pressure to the wound, immobilize the limb, and seek urgent medical attention. Hospitals do have effective antivenoms for this type of snake, but it must be properly administered.
It’s always best to avoid encountering an eastern brown snake because they’re not only venomous but also highly aggressive. However, it’s important to keep in mind that there’s also the common brown snake that isn’t as dangerous. Still, it’s best to avoid both just to be safe. When out and about in eastern brown snake territory, take care to wear protective clothing and be vigilant about the snakes’ presence. If you do spot one, stay well back.
5. Stonefish (Synanceia spp.)
Found around the coastal regions of northern Australia, the stonefish holds the title of being the most venomous fish in the world. Not only this, but they’re masters of disguise, using camouflage to help them catch prey. Unfortunately, this means they’re also commonly encountered by humans, who cannot see them as they wade through the water.
One good thing is that this isn’t an aggressive species and won’t attack humans unless provoked. But if you step on one, then their venomous spines deliver verrucotoxin which can result in pain, swelling, and difficulty breathing. This is why it’s super important to get medical assistance as quickly as possible. While stonefish venom can be fatal, most people make a full recovery 24-48 hours after the sting. Still, it’s worth keeping in mind that around 1000 stonefish stings are reported annually in Australia.
In some parts of Asia, people actually eat stonefish, but just like the pufferfish, this dish has to be properly prepared if it’s going to be safe to consume.
There are several species of stonefish native to Australis, including the most venomous; the estuarine stonefish. This is found in the northern part of the country, and it’s best to wear protective footwear when wading in the water. What’s more, if there are a lot of objects on the seafloor where stonefish could hide, distribute these before taking a step.
But despite the potential dangers of stonefish, it’s important that we find ways to protect them as this species is threatened by ocean pollution and habitat loss.
6. Bull Shark (Carcharhinus leucas)
When asked to think of a shark in Australia, I’d bet most of you would mention the great white. However, there is another large, aggressive species found swimming in both coastal and freshwater ways in Australia, the bull shark.
Unlike the great white, bull sharks can cope with varying levels of salinity, so they have a much wider distribution and are often found in the Swan and Brisbane Rivers. What’s more, while the great white has a nasty reputation, it’s actually the bull shark that’s responsible for a large number of shark attacks and is thought to be the main perpetrator of near-shore attacks on humans.
Bull sharks are often mistaken for great whites, but note their stout bodies and long dorsal fins. These sharks usually have gray coloration to the top and white on the underside. Some younger sharks may have much darker fins that fade as they get older.
In many areas, the government has installed nets to prevent these aggressive fish from making contact with humans, as well as implementing education campaigns so that humans are better able to understand the risks and how to prevent attacks. One of the most sensible ways to avoid encountering one of these sharks is to avoid swimming in areas where they live.
While these sharks are a threat to humans, they’re still an important part of the marine ecosystem and should be treated as such. With this in mind, conservationists are looking at ways to protect populations as things like pollution, overfishing, and habitat loss have caused their numbers to decline.
7. Blue-Ringed Octopus (Hapalochlaena maculosa)
The blue-ringed octopus is truly a beautiful creature with small blue and black rings that change color when the octopus is threatened, on a background of yellowish white skin. But looks can be deceiving, and in fact, this is one of the most venomous animals on the planet, and it’s lurking in the coastal waters of southern and eastern Australia.
Blue-ringed octopus venom contains a neurotoxin called tetrodotoxin, which can cause your respiratory system to fail and cause paralysis. It can even cause death, although the number of annual deaths is disputed but could be as high as 11. Unfortunately, there is currently no antidote for this type of venom, so the best thing to do is avoid these creatures at all costs.
You’ll often see them in rockpools and shallow water, so avoiding entering the water is the most obvious solution to preventing a sting. If you must enter the water then I’d recommend keeping as far away as possible from these creatures and do not touch them, no matter how beautiful they might look. Many swimmers accidentally step on or touch a blue-ringed octopus, and if this happens to you, get to the hospital as soon as possible.
8. Great White Shark (Carcharodon carcharias)
The great white shark has been portrayed in movies for decades as one of the most dangerous fish in the world. But did you know that most great white attacks are unintentional and they occur when these beasts mistake humans for prey?
Still, growing up to 2,400 lbs (1,100 kg) and measuring a whopping 20 feet (6 meters) (the largest recorded individual was spotted in 1959 and measured 21 feet (6.4 meters)) with 300 razor sharp teeth, it’s often difficult to survive the attack in one piece. These traits are vital to these apex predators and they’re also able to swim at speeds of up to 35 mph (56 km/h).
If you’re ever unfortunate enough to find yourself face to face with a great white, then the general advice is to do whatever you need to escape. Fighting back and acting aggressive can startle the shark, especially if you go for the nose, eyes, or gills. Still, you’ll likely find yourself with some serious injuries.
Australia has something of a reputation for its shark attacks, and since 1900, there have been 170 fatalities as a result of unprovoked great white attacks. In 2020, the country reported 22 unprovoked attacks which made up more than 38% of global reports. In fact, some of the most high profile cases of great white attacks occur in the waters around this nation.
They might be portrayed as monsters, but great white sharks are an important predator in the marine ecosystem. Without them, smaller fish species populations would grow and cause an imbalance. Sadly, there are thought to be just 3500 left in the wild and many of these are found around the western and southern coasts of Australia.
In order to save these amazing creatures, the Australian government has implemented several measures, but they’ve also provided resources to the public to limit the number of attacks. It’s perfectly possible for both humans and sharks to be safe. One such example of this is the restriction on fishing quotas to protect the sharks while nets have been installed around beaches to lower the number of attacks.
Still, there’s a lot you can do to protect yourself, including following beach signs and not entering the water when great whites are present; after all, we’re entering into their territory.
9. Cone Snail (Conus spp.)
There are more than 900 species of cone snail and to the untrained person, they probably don’t look very threatening. But these marine mollusks pack a real punch and have venom containing conotoxins that they primarily use when hunting. However, each species of cone snail has its own unique concoction of venom, including peptides which can result in paralysis of the muscles, the respiratory system, and can even cause heart failure.
That said, research is taking place into the beneficial uses of cone snail venom, and it’s thought that it could act as a treatment for malaria. What’s more, it could also have potential in insulin therapies due to how quickly cone snail insulin binds with that of a human.
In Australia, there are many cone snail species, but one of the most dangerous is the textile cone snail (Conus textile) which is usually found in the northern parts of the country along the coast. Another dangerous species is the geography cone (Conus geographus), but there has only ever been one reported death from this species, whereas other species have caused several deaths in Australia.
The good news is that these deaths are few and far between and only really happen when humans accidentally step on the snails or handle them. With this in mind, it’s best to wear protective footwear when in the water and don’t be tempted to pick up these creatures.
In the unlikely event that you do receive a cone snail sting, this should be treated as a medical emergency. If you aren’t sure whether the offending mollusk was a cone snail, consider its appearance. Cone snails, as their name suggests, have a conical shell with an obvious whorl at the top. Depending on the species, the shell could be one of many textures.
While there is no antivenom for cone snail stings, doctors can help to manage symptoms and make you more comfortable. In a lot of cases, not enough venom is delivered to kill a person, but you may still experience things like tingling, numbness, and pain.
10. Irukandji Jellyfish (Carukia barnesi)
Along the northern coasts of Australia, you may be unfortunate enough to run into an irukandji jellyfish. These might be small (around the size of your thumbnail with tentacles as long as 3.3 feet (1 meter)), but their venom is mighty and has the potential to kill a human. The problem is that they’re so tiny, people struggle to spot them in the water before it’s too late.
Another issue with the irukandji jellyfish is that there’s no specific season when it’s more active; stings occur all year round in Australia, although they are more common between November and May when the weather is warmer.
While there is no specific antivenom for the venom of irukandji jellyfish, which contains sodium channel modulators, their stings can cause severe symptoms, including pain, vomiting, cramping, sweating, and, in some cases, even heart failure and death. Fatalities are not common, but there have been reports of stings, with approximately 159 cases occurring over a five-year period.
When you’re stung by this type of jellyfish, you may suffer from irukandji syndrome, which can cause intense pain, cardiac complications and even death!
The irukandji jellyfish takes its name from the Aboriginal tribe of the same name who were around when the creature was initially discovered. Today, it has a reputation for being one of the most dangerous marine animals in the country.
But, as with most other Australian abominations, there are things you can do to avoid being the victim of a nasty sting. For starters, wearing protective clothing when you enter the water is a must. But, if there are beach signs advising you not to go; don’t!
11. Redback Spider (Latrodectus hasselti)
The redback is a type of widow spider and is highly venomous. Most people are afraid of large spiders, but the redback doesn’t typically grow to more than 0.4 inches (1 cm) in body length, with males being significantly smaller. Females also have a red stripe on the back. But being small doesn’t mean they’re not scary, and their venom contains a neurotoxin called alpha-latrotoxin, which can cause death.
Children and vulnerable adults, such as the elderly, are more likely to become fatalities of redback bites. Most healthy adults suffer symptoms like sweating, vomiting, muscle spasms, and pain but with antivenom, usually recover relatively well.
The problem with the redback spider is that it often comes into contact with humans. What’s more, it’s found all over Australia and is a common pest in homes where it’ll hide in garages, sheds, and among rock piles. Fortunately, this species isn’t aggressive and typically only bites if it feels threatened, so it’s best to keep away from them.
But while around 10,000 bites are reported each year, there has only been one death from a redback spider in the last seven decades. However, if you are bitten, the most important first aid you can take is to apply an ice pack.
12. Australian Funnel-Web Spider (Hadronyche cerberea)
Found mainly in eastern Australia, the Australian funnel-web spider has some of the most potent venom in the world, and it can cause a range of symptoms in humans. These include vomiting, sweating, high blood pressure, and muscle spasms. These venoms contain a cocktail of toxins, and it’s reported that there could be as many as 44 components. While there is antivenom available, this needs to be sought as soon as possible because prolonged exposure to the venom can be fatal. It’s thought that up to 40 people every year are bitten by these spiders.
Not only this but the males have super long fangs, even though their body size is smaller than the females, and can penetrate even leather boots. You can identify them because of their glossy body that may be dark brown or black in color and their helmet-like head. What’s more, this species, just like the Sydney variety, builds a funnel shaped web to capture prey.
The problem with this species is that it is not only highly venomous, it’s also incredibly aggressive and will strike with minimal provocation. This is why it’s essential for people to keep well away from Australian funnel-web spiders and be aware of when they’re most active, which is during the summer months. But you’ll also notice males becoming more active during the autumn when breeding season occurs.
It’s also worth noting that, while they are usually found in forests, they’re a common occurrence in domestic gardens, so humans should be vigilant and wear protective clothing when doing yard work.
13. Coastal Taipan (Oxyuranus scutellatus)
The coastal taipan is a species of venomous snake that, as its name suggests, is found around coastal areas in Australia. These are rather large snakes, and adults can grow up to 8.2 feet (2.5 meters) in length. However, smaller specimens are often recorded.
To identify this snake, you’ll want to look for a species with a broad, triangular-shaped head but a slender body. The fangs are fixed, and it’s these that deliver a toxic venom which contains both neurotoxins and coagulopathic agents. The result of being bitten by a coastal taipan could be organ failure, internal bleeding, and even paralysis. If you don’t seek immediate medical attention and receive the appropriate antivenom then a bite could be fatal.
However, despite being the third most venomous snake in the world, the coastal taipan isn’t likely to bite unless provoked; it’s generally a pretty docile animal. In fact, these snakes are considered to be important players in the local ecosystems and will prey on birds, rodents, and even small reptiles, keeping the biodiverse balance in order. Because of this, the species is protected by law.
14. Common Death Adder (Acanthophis antarcticus)
With a name like the common death adder, you’d be right to be wary of this species. It possesses a highly toxic venom that can cause death. Even for those that are lucky enough to survive, the bite may even cause paralysis. Thankfully, there is an antivenom available for the common death adder and, as long as you seek urgent medical care, your chances of survival are good. However, the antivenom was only invented in the 1950s and before this, as many as 50% of all victims met their demise.
Common death adders are largely found in the southeast and eastern parts of Australis and may be red-brown to gray or black in color. Similar to the previous snake, these adders have a triangular head but can be distinguished because of their thicker body and banding. They tend to grow to around 3.3 feet (1 meter) in length.
These snakes are nocturnal, so it’s incredibly important not to walk in unlit areas and use a torch to light your way. Since they largely rely on camouflage, common death adders can be tricky to spot, and they’ll also strike very quickly. So, if you’re in woodlands or grasslands at night, it’s best to stay alert and be sure to wear protective clothing to avoid being bitten.
Common death adders are not currently under any threat, although they are facing issues with habitat loss, which could cause population declines in the future. However, at the time of writing, they’re not under any protective laws.
15. Tiger Shark (Galeocerdo cuvier)
This wouldn’t be a complete list of the most dangerous Australian animals without including another shark; the tiger shark! This is a large species that can reach up to 16 feet (4.9 meters) and weigh as much as 1,400 lbs (635 kg). Younger tiger sharks have a striped body, which is where they get their name, although these stripes fade as the shark gets older.
While the primary diet of the tiger shark is made up from fish, seabirds, turtles, and even other sharks, they are known to attack humans. However, as is the case with the great white, it’s not usually intentional and occurs because they often feed in the shallow waters where humans do recreational activities. Because of this, tiger sharks are often thought to be the most dangerous shark species to humans.
Tiger sharks are found all around the coasts of Australia, and attacks have been recorded all over the place. However, most occurrences take place in the Coral Sea, the Timor Sea, and the Arafura Sea. In Queensland, authorities have taken action and installed a Shark Control program, installing nets to reduce the number of shark attacks.
Despite the risk that tiger sharks pose to humans, they still need to be protected as they, just like other sharks, play an important role in the marine ecosystem. Studies suggest that the aforementioned control programs along with fishing could have wiped out populations along the east coast of the country.
To avoid being attacked by a tiger shark, you should always stay close to the shore, preferably with other people, since sharks are more likely to attack a solitary individual.
16. Australian Paralysis Tick (Ixodes holocyclus)
According to the Mayo Clinic, of the hundreds of species of ticks in the world, only around 60 are known to bite, and around 69 species are capable of paralyzing their hosts. The Australian paralysis tick is one of them, and it’s usually found on the eastern coast but also on the Australian island of Tasmania. These ticks are active in the warmer months, typically between September and March.
Where a lot of ticks merely attach themselves to their hosts, this species is also known to possess a potent neurotoxin, which can result in paralysis and is a problem for both humans and animals. When ticks attach, they do so in order to feed on the blood of their hosts, but when this tick attaches, it injects venomous saliva, and that’s where problems start.
If you find yourself with an Australian paralysis tick, the first symptoms you may notice could include difficulty breathing, difficulty swallowing, and weakness in your muscles. Although how severe these symptoms are varies between cases according to things like the length of time the tick has been attached and your own natural immunity.
Naturally, humans will want to avoid any encounters with the Australian paralysis tick, so wearing long pants and sleeves will reduce the amount of available skin it can attach to. This is especially important when moving through grassy areas where these ticks are rife. However, if you are unfortunate enough to find one on you, you’ll need to use tweezers to gently remove it. After this, it’s vital that you keep an eye on your symptoms and seek medical attention where necessary.
It’s also worth noting that, after a tick bite, you may develop mammalian meat allergy which means that you’ll no longer be able to eat certain types of meat. However, there is a course of medication you can take to overcome this allergy.
17. Inland Taipan (Oxyuranus microlepidotus)
We’ve already met the coastal taipan, but if you thought that was dangerous, wait until you meet its cousin; the inland taipan. This is sometimes called the fierce snake and is thought to be the most venomous land snake in the world.
These snakes are endemic to Australia and are usually found in semi-arid regions. However, there is some good news; these are very timid snakes, and it’s not often that they come into contact with humans. But when they do, their venom can result in death if you aren’t treated in time. Studies have shown that their venom is so potent that a single bite has the capacity to kill as many as 250,000 mice!
As with many other creatures on this list, it’s essential to seek urgent medical attention if you are bitten. That said, while antivenom is available, this is one of the more complicated snake bite treatments, which again presses the urgency of seeking help quickly.
So, what is it that’s so devastating about the inland taipan’s venom? Well, it contains neurotoxins, hemotoxins, and mycotoxins, which all attack the body in different ways. Some symptoms you may experience include muscle paralysis and respiratory failure. Usually, these snakes use their venom to catch and immobilize prey like small mammals and rodents.
Of course, these snakes do pose a risk to humans, but we want to try and protect them, which is why conservationists have made efforts to minimize the risk of human contact at the same time as protecting the snakes’ habitat.
18. Belcher’s Sea Snake (Hydrophis belcheri)
The Belcher’s sea snake, named after the man who discovered it in the 1800s, is undoubtedly a beautiful snake with a cream body and dark green bands. They are only small, growing to around 3.3 feet (1 meter), but they’re also considered to be the most venomous type of sea snake in Australia, so don’t let their looks fool you! Although this pattern does serve as an effective warning to predators to stay away.
These sea snakes are found around the northern coasts of Australia in the Timor and Arafura seas where it preys on eels and small fish as a nocturnal hunter.
The Belcher’s sea snake venom comes in very handy when it’s hunting, but it’s also known to contain neurotoxins that are highly dangerous to humans. While the venom can cause paralysis and other symptoms, if left untreated, a bite can lead to death. Fortunately, there is an antivenom for this, so most people make a full recovery.
Moreover, Belcher’s sea snake, along with other species of sea snake are not known to act aggressively towards humans unless they feel threatened. Most occurrences of bites take place when accidental contact is made that alarms the snake.
Of course, the best thing to do when you’re in the water is to avoid all sea snakes, as most of them are venomous.
19. Southern Cassowary (Casuarius casuarius)
The southern cassowary is the first and only bird species on this list, and it’s often considered to be one of the most aggressive and dangerous birds in the world. The cassowary defends itself using a powerful kick with a force the same as the bird’s weight; around 160 lbs (73 kg)! When they deliver this deadly kick, it can be enough to kill small animals, and there was even a report of a man being killed by his pet cassowary in 2019.
These large flightless birds have a telltale blue casque on their heads, which they also use to defend themselves and for protection of the skull. Growing up to 6.6 feet (2 meters) in height, they are considered to be the third tallest bird in the world as well as being the second heaviest.
If you ever find yourself faced with an angry cassowary then it’s best not to run away, as the bird will likely be able to outrun you. Instead, you should face the bird and slowly back away to prove you’re not a threat. It’s also a good idea to protect your body using a backpack, if you have one to hand.
While these birds are known for their aggressive tendencies, they’re sadly under threat as a result of habitat loss. It might not seem important knowing their nature, but the cassowary is an important cultural symbol to many of the indigenous Australian people.