The saltwater crocodile, also known as the estuarine crocodile or saltie, is the largest of all living reptiles. Males can exceed 6m in length and a tonne in weight and are widely touted as producing the strongest bite-force of any animal.
Like other crocodilians, they dismantle their prey using a manoeuvre called the ‘death roll’, which involves grasping a limb or head in their jaws and rolling vigorously in the water until it separates from the body. Their heavily armoured bodies endow them with an air of utter impregnability. But can their defences be breached? And if so, by whom?
Animals that could kill a saltwater crocodile
Orca
Saltwater crocodiles can thrive in a range of habitats, including coastal waters, rivers, estuaries, swamps and marshes. They are quite capable of making long journeys across the open ocean, which can bring them in contact with orcas: apex predators with a similarly strong bite.
Orcas are around four times the weight of salties, faster and more agile. They have been observed working as a pod to kill blue whales, immobilising them with an onslaught of biting and head-butting, so salties are small-game by comparison. As far as we know, though, there are no records of orca attacking salties. But that doesn’t mean it doesn’t happen.
Great white shark
Salties might also encounter sharks on their oceanic forays. If any shark is going to get the better of a saltie, it will have to be a big one, and surely the great white, the biggest of all predatory sharks, is the most likely candidate.
The biggest great whites and the biggest salties are well matched for size, and both are armed with deadly dentition. But in the open ocean, a great white is in its element, while a saltie – an ambush predator that usually lurks close to shore – is a bit of a fish out of water, which might tip things in the shark’s favour. Again, though, it seems that no one has ever found themselves in the right place at the right time to witness the outcome of such an altercation.
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Humpback whale
Another ocean-going species that salties might wish to avoid is the humpback whale, as these gentle giants have a feisty side. They are the only species of cetacean that will actively approach pods of orcas to drive them away. Orcas are partial to humpback calves, so the whales have good selfish reasons to deter them. But there’s an altruistic element to it, too: their protective instincts extend to driving off orcas that threaten other animals, such as dolphins, seals and big fish.
Humpbacks’ bravery and selflessness might stem from their being the only large whales equipped with weaponry at both ends. At the back, the regulation tail flukes are capable of delivering a mighty slap. Up front, there are two strikingly elongated pectoral flippers, each up to 5m long and weighing over a ton, which can be wielded offensively with both finesse and power. Each has a knobbly leading edge often encrusted with the jagged flesh-tearing shells of barnacles.
If these weapons are good enough to see off a pod of orca, what could they do to a lone saltie about a 40th of their own weight? There’s no reason to think humpbacks and salties ever come into violent conflict, but it might pay the crocodiles to give the whales a wide berth, just in case.
Reticulated python
Like a boa or anaconda, a python kills its prey by constriction rather than with venom. Following an initial grasping bite, it coils its body around its victim and squeezes very hard, causing death by asphyxiation. The snake’s slack-hinged jaws and elastic skin enable a gape wide enough to allow the passage of animals of a girth far exceeding its own.
Reaching over 6m in length, the reticulated python is the world’s longest snake, and is big enough to swallow a human whole. Its range in South and Southeast Asia overlaps with that of the saltwater crocodile, so the two species might come into contact. However, a mature saltie is three times as long as a human is tall and significantly girthier – too big a mouthful, perhaps, even for this giant serpent.
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Elephant
According to Rudyard Kipling’s Just So Stories, it was a painful tug of war with a crocodile on the banks of the ‘the great grey-green, greasy Limpopo River’ that gave the elephant its extraordinary trunk. But elephants have more reason than that to be wary of crocodiles, as footage of a saltie killing an Asian elephant calf in Borneo was captured in 2022. And elephants supposedly never forget.
An African elephant can easily kill a crocodile by trampling it, and there’s little reason to think an Asian elephant couldn’t do the same to a saltie. It could probably do it by sitting down on it.
Big cats
In South America, jaguars routinely make short work of caimans, smaller relatives of the crocodiles, dispatching them with a bone-crushing bite to the back of the skull. So, scale things up to a really big cat, such as a lion or a tiger, and a really big crocodile, such as a saltie, and we might have a contest on our hands.
Lions perhaps have the best chance here, in that they usually hunt cooperatively, so could overwhelm a saltie through weight of numbers. However, while salties occur in Australia, Southeast Asia, and the south-west Pacific, lions are confined to Africa and a small population in the west of India, in which case, its unlikely that they ever get to meet. That said, lions were once more widespread across the Indian subcontinent, so it’s quite possible that they could have come to blows in the not-too-distant past.
Tigers, like jaguars, are solitary beasts, and, unlike lions, they do share territory with salties. And they are known to take crocodilians occasionally – they too have been filmed killing crocs with a bite to the base of the skull. Whether they could handle a full-grown saltie in this manner is another matter. Its quite possible that any such a contest would be decided by who got the first bite in.
Human
Homo sapiens is almost certainly the saltwater crocodile’s most significant predator. Aboriginal people in northern Australia have harvested its eggs for millennia, and it was hunted intensely for its valuable skin from the 1940s until the 1970s, when it received legal protection. But we haven’t had it entirely our own way. Salties kill and eat people with some regularity: there were 106 crocodile-inflicted deaths in Australia alone between 1971 and 2013.
Hippopotamus
Hippos are not renowned for the sweetness of their personalities. But they reserve a special sort of tetchiness for the crocodiles that share their stretch of the river. Nile crocodiles can do little harm to a healthy adult hippo, but they are very partial to their calves.
Little surprise that hippos will take every opportunity they can to make crocodiles feel unwelcome: there’s no shortage of videos out there of hippos doing serious damage to Nile crocodiles that have got too close. But a Nile crocodile is merely the second biggest crocodilian on Earth. We may never know if a hippo is capable of dispatching a saltie with the same brutal efficiency, because the two species live on different continents.
Cane toad
Lastly, we have a true giant killer. This David to the saltie’s Goliath is the cane toad, an amphibian imported to north-eastern Australia from its native tropical America in the 1930s to control agricultural pests, since when, it has spread eastwards spectacularly.
Protected by potent toxins secreted from glands in its head, the cane toad poses a danger to native predators – quolls, snakes and monitor lizards – that have not learned to avoid it. Some populations of Australian freshwater crocodiles have been reduced by over 70 per cent as a result of toad poisonings. Salties are more tolerant of the toxins, but not immune to them, and may receive a lethal dose if they eat enough toads.
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Main image: saltwater crocodile. Credit: Getty