Adult Tasmanian devils have virtually no natural predators in modern Tasmania. As the largest surviving carnivorous marsupial, they occupy the top of the island’s mammalian food chain, and nothing routinely hunts them. The more interesting story is about what used to prey on them, what kills juveniles before they reach full size, and the introduced species and human-caused threats that now do far more damage than any predator ever could.
Why Adults Sit at the Top
A full-grown Tasmanian devil weighs roughly 8 to 14 kilograms and has one of the strongest bites relative to body size of any living mammal. That jaw strength, combined with a stocky, muscular build and notoriously aggressive temperament, makes an adult devil a poor target for anything else living on the island. Tasmania simply lacks large land predators. There are no big cats, no wolves, no large reptilian ambush predators. The wedge-tailed eagle is the biggest aerial predator in the region and could theoretically take a very young or sick devil, but healthy adults are not on its menu.
Devils are also largely nocturnal, spending daylight hours in dens among rocks, logs, or burrows. Their dark coloring blends well into the forest floor and scrubby undergrowth where they forage. This combination of physical toughness, aggression, and nighttime activity means that in Tasmania’s current ecosystem, nothing has evolved specifically to hunt adult devils.
The Dingo and the Disappearance from the Mainland
Tasmanian devils once ranged across mainland Australia. Fossil and subfossil records show they were widespread until a few thousand years ago. Their disappearance from the continent is widely attributed to the arrival of the dingo, which reached Australia roughly 3,500 to 4,000 years ago. Devils survived in Tasmania because dingoes never made it across the Bass Strait, which had already flooded as sea levels rose at the end of the last ice age.
The dingo is considered the primary suspect for the mainland extinction of three native species: the thylacine, the Tasmanian devil, and the Tasmanian native hen. All three vanished from the mainland during the late Holocene in the presence of dingoes, yet persisted in Tasmania where dingoes were absent. Researchers have argued that dingoes plausibly competed with devils for food and may have directly preyed on them, particularly juveniles and smaller individuals.1CrossRef / The Holocene. Causes of extinction of vertebrates during the Holocene of mainland Australia: arrival of the dingo, or human impact? There is still some debate about whether dingo competition alone drove these extinctions or whether intensifying Aboriginal land management, including burning and hunting, played a contributing role. The leading view is that dingoes were the dominant factor, given that the timing and geography fit so neatly: the species survived exactly where dingoes did not.
The dingo, then, is the closest thing to a true predator the Tasmanian devil has faced in recorded ecological time. It is a canid roughly two to three times the size of an adult devil, fast enough to chase them down in open country, and social enough to hunt cooperatively. On the mainland, dingoes filled a niche as a medium-sized apex predator that devils simply could not outcompete.
Introduced Foxes and the Risk They Pose
Red foxes were introduced to mainland Australia in the 1850s for recreational hunting and have since become one of the most destructive invasive species on the continent. Evidence of foxes reaching Tasmania emerged in the early 2000s, and the Tasmanian government launched a fox eradication program in response. The presence of foxes on the island represents a serious potential threat to devils, not only through direct predation of juveniles but also through competition for food.2The Journal of Wildlife Management. A preliminary study assessing risk to Tasmanian devils from poisoning for red foxes
Foxes are roughly similar in size to devils and occupy a comparable scavenging and opportunistic-hunting niche. If foxes were to establish a breeding population in Tasmania, they could compete directly with devils for carcasses and small prey, while also preying on the smaller native marsupials that devils depend on. The eradication program used Foxoff baits containing sodium monofluoroacetate (known as 1080), a poison that is also attractive to native carnivores. This created a painful irony: the effort to protect the ecosystem from foxes could inadvertently poison the very devils it aimed to help. Researchers investigated the risk to devils from these baits and flagged it as a significant concern, given that the devil population was already under enormous pressure from devil facial tumor disease.2The Journal of Wildlife Management. A preliminary study assessing risk to Tasmanian devils from poisoning for red foxes
Whether foxes have truly established themselves in Tasmania remains debated. Confirmed sightings have been sporadic and contested. But the threat is taken seriously enough that monitoring continues. If foxes were to gain a foothold, they would become the first land predator in Tasmania capable of regularly killing juvenile devils and competing with adults.
Feral Cats and the Mesopredator Dynamic
Feral cats are already well established across Tasmania, but they do not prey on adult devils. The relationship runs in the other direction: devils suppress feral cat populations. Research using the dramatic decline of devil numbers caused by devil facial tumor disease as a kind of natural experiment found that feral cat abundance was about 58% higher in areas where devils had declined compared to areas where devil populations remained healthier.3PubMed. A native apex predator limits an invasive mesopredator and protects native prey: Tasmanian devils protecting bandicoots from cats This increase in cat numbers in turn negatively affected smaller native prey species like bandicoots.
The research also found something striking about how this suppression works. Devils had a stronger limiting effect on the invasive cats than they did on a native mesopredator, the spotted-tailed quoll, which has coexisted and co-evolved with devils for millennia.3PubMed. A native apex predator limits an invasive mesopredator and protects native prey: Tasmanian devils protecting bandicoots from cats The interpretation is that feral cats, having never evolved alongside a dominant marsupial predator, are more susceptible to being displaced by devils than quolls are. Quolls have had thousands of years to develop behavioral strategies for coexisting with devils, such as adjusting where and when they forage.
So while feral cats are not a predator of devils, the interaction between the two species is a crucial part of the Tasmanian food web. When devils are removed from the equation, cats thrive and smaller native mammals suffer. This makes the devil less a species at risk from cats and more of a bodyguard that shields other native species from them.
What Threatens Juveniles
Young Tasmanian devils are far more vulnerable than adults. A devil joey at a few months old weighs only a fraction of what an adult weighs and lacks the jaw strength and aggressive temperament that protects older animals. At this stage, large birds of prey, large snakes, and other carnivorous marsupials could potentially take them. The spotted-tailed quoll, Tasmania’s second-largest marsupial carnivore, is a skilled and agile predator that overlaps with devils in habitat and diet. Quolls can climb trees and hunt actively in ways that devils, which are primarily ground-dwelling scavengers, do not.4Austral Ecology. Space use and temporal partitioning of sympatric Tasmanian devils and spotted‐tailed quolls
That said, the dominant direction of the quoll-devil interaction is competition, not predation. Adult devils displace quolls at food sources, and quolls seem to compensate by partitioning their space and activity times to reduce direct encounters with devils. A quoll taking a devil joey is opportunistic rather than routine. The same applies to wedge-tailed eagles, which are powerful enough to kill a small devil but for which devils are not a regular prey item. The main vulnerability for juveniles is less about being actively hunted and more about the general dangers of being small in a landscape full of opportunistic predators.
Devils as Apex Scavengers
To understand why so few things eat Tasmanian devils, it helps to understand what devils themselves eat. They are primarily scavengers rather than active hunters. Research using animal-borne video collars showed that devils spent more time scavenging than hunting and exhibited flexible, opportunistic foraging behaviors. They scavenged mostly in natural vegetation but also along roads, fence lines, and other human-altered landscapes. Smaller carcasses were scavenged most frequently.5PubMed Central. Activity and social interactions in a wide-ranging specialist scavenger, the Tasmanian devil (Sarcophilus harrisii), revealed by animal-borne video collars
This scavenging role makes devils ecologically more like vultures than like wolves. They clean up carcasses efficiently, consuming bone, fur, and all. Their powerful jaws can crack through bones that other scavengers cannot handle, which means a dead wallaby on the forest floor gets consumed more quickly and more thoroughly when devils are around. When devil populations decline, the consequences ripple through the ecosystem in ways that go beyond the simple food chain.
What Happens When Devils Disappear
The collapse of devil populations across much of Tasmania due to devil facial tumor disease has provided researchers with an unintended large-scale experiment in what happens when an apex scavenger is removed. The results have been sobering.
Remote camera studies using experimentally placed carcasses showed that when devils decline, mesopredators like quolls and feral cats consume more carrion. Feral cats in particular responded to the broader landscape-level absence of devils rather than just local competition at carcass sites, suggesting that where devils are suppressed, cats move more freely and exploit resources they would otherwise avoid.6PubMed Central. Top carnivore decline has cascading effects on scavengers and carrion persistence Meanwhile, the invertebrate scavenging community expanded dramatically. Carrion beetles and blow fly larvae were about twice as abundant at carcasses in low-devil-density areas compared to sites where devil populations remained at intermediate or high levels. Beetles persisted at carcasses for about 10 days in low-density areas, compared to roughly 5 days where devils were still regularly visiting and consuming the carcasses first.7PubMed. Decline of an apex vertebrate scavenger increases carrion use by invertebrates
These changes extend to soil chemistry and ecosystem processes. While invertebrates and smaller scavengers picked up some of the slack left by declining devils, they could not fully replace the functional role of the apex scavenger. The carcass decomposition process shifted, nutrient cycling around carcass sites changed, and the overall efficiency of the scavenging system dropped.8PubMed. Apex Scavenger Declines Have Cascading Effects on Soil Biogeochemistry and Ecosystem Processes Devils are not just another link in the food chain; they are something closer to a keystone species whose absence destabilizes the decomposition and predator-prey dynamics of the entire Tasmanian ecosystem.
Vehicles and Roads
If you ask what actually kills the most Tasmanian devils today, the honest answer is not a predator at all. Devil facial tumor disease has devastated the population since it was first documented in the mid-1990s, reducing some local populations by over 80%. But the second major killer is motor vehicles. Devils are drawn to roads because roadkill provides easy scavenging opportunities. A dead possum or wallaby on the pavement is a predictable meal, and devils are not especially cautious about traffic.
This problem is compounded for captive-bred devils released into the wild as part of conservation programs. A study of reintroduced devils found that the number of generations an animal had spent in captivity was the strongest predictor of death by vehicle strike. Devils that came from families with more captive generations were dramatically more likely to be hit by cars than those with fewer generations in captivity.9PubMed Central. Increasing generations in captivity is associated with increased vulnerability of Tasmanian devils to vehicle strike following release to the wild The effect was stronger than age, sex, or release location. This likely reflects a loss of road-avoidance behaviors that wild-born devils develop through experience and, possibly, a gradual behavioral shift over generations of living in enclosures without traffic.
For conservation programs trying to rebuild devil populations, this is a real headache. You can protect a species from disease, breed it successfully in captivity, and release it into suitable habitat, only to lose individuals to cars because they never learned that roads are dangerous. Mitigation strategies like wildlife crossing structures and reduced speed zones in key habitat corridors have been discussed, but implementation across Tasmania’s rural road network is slow.
Mainland Reintroduction and New Predator Pressures
In 2020, Tasmanian devils were reintroduced to mainland Australia for the first time in roughly 3,000 years, with a small population released into a wildlife sanctuary in New South Wales. The goal was partly insurance against the continued spread of devil facial tumor disease in Tasmania and partly ecological: researchers hoped that devils could once again suppress feral cats and foxes on the mainland, restoring some of the trophic balance that was lost when devils disappeared.
But reintroduction to the mainland puts devils back in contact with dingoes, the very predator that likely drove their extinction there in the first place. The sanctuary environments used for the initial releases exclude dingoes behind fences, creating a controlled setting. Whether free-ranging devil populations could coexist with dingoes on the mainland, perhaps in areas where dingo numbers are low or where habitat provides enough cover and den sites, remains an open question. The mainland also has a far denser population of feral cats and foxes than Tasmania does, which means the competitive landscape is more crowded.
Early results from the mainland reintroductions have been cautiously positive in terms of breeding success, but the long-term viability of unfenced mainland populations is unknown. The challenge is not just whether devils can survive individual encounters with dingoes, foxes, and cats, but whether they can establish self-sustaining populations in a predator community that is fundamentally different from the one they left behind thousands of years ago.
The Spotted-Tailed Quoll Relationship
The interaction between Tasmanian devils and spotted-tailed quolls deserves a closer look because it is one of the few predator-competitor relationships involving devils that plays out between native species in real time. Quolls are smaller, lighter, and more agile than devils, and they are active hunters as well as scavengers. The two species overlap substantially in diet and habitat, which creates potential for direct competition.4Austral Ecology. Space use and temporal partitioning of sympatric Tasmanian devils and spotted‐tailed quolls
In practice, devils dominate these interactions. They are bigger, stronger-jawed, and more aggressive at carcass sites. Quolls compensate by being more arboreal, hunting a wider range of prey including birds and insects in trees, and adjusting their activity patterns to avoid peak devil activity times. This kind of temporal and spatial partitioning allows both species to persist in the same landscape without one completely excluding the other.
The decline of devil populations has shifted this dynamic. With fewer devils around, quolls have been observed scavenging more boldly at carcass sites and in areas they previously avoided. Whether this benefits quolls in the long run is unclear, because the same devil decline that reduces competition for quolls also releases feral cats, which compete with quolls for small prey and could even prey on quoll juveniles. The relationship among these three species is a tangled web in which removing the top predator does not simply benefit the next one down the ladder. Instead, it reshuffles the entire competitive landscape in ways that are difficult to predict and that often favor the invasive species over the native ones.