The Retriever, Dog, & Wildlife Blog

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There’s a chance that they might– but it’s not very good.

The thylacine or Tasmania tiger is a marsupial carnivore closely related to the Tasmanian devil and the quolls. (In fact, I think quolls look like mini-Thylacines).

It became extinct on the Australian mainland around 3,000 years ago, not long– in natural history time– after the arrival of the dingo. Man further burned large sections of the mainland as part of their hunting strategy. These big marsupials preferred to hunt in denser cover than the open plains. In an arid country, such extensive burning resulted in fewer plants growing on the landscape, and fewer plants meant less cover for a predator that hunted using the cover.

Further, dingoes were far more adaptable than the thylacine. Dingoes were able to eat a wider range of prey and form packs to hunt effectively. The dingo also has a thicker skull than the thylacine had, and with a thicker skull, it could withstand blows from larger prey than the thylacine. Also, dingoes were able to suck up to the early Native Australians, who allowed them free range of their camps, where they could augment their diets through scavenging.

That’s why they were able to survive in Tasmania for there were no dingoes and little burning.

The last thylacine died in 1933. “Benjamin” was a captive at the Hobart Zoo in Tasmania. Despite the name, this specimen’s gender is still unknown.

Today, both Tasmania and mainland Australia have thylacine sightings. Many of these can be attributed to foxes or dingoes with mange. However, Tasmania has no dingoes, and it has a very small fox population, which is heavily culled for fears that the foxes will kill off small native marsupials on the island and is even further culled by the Tasmanian devils, which eat fox kits. It is possible that a population of these beasts still lives in the Tasmanian forests. If they do exist, they are critically endangered and have very low genetic diversity. Until we get better evidence of their existence, though, we have to say that they are extinct. I’d love to be proven wrong on this– I really would.

Interestingly,  it is thought that three factors led to their extinction in Tasmania. The first of these is that people shot them, and there was a bounty system on “tigers.” The dense forests of Tasmania were also being felled, and the thylacines lost their stalking cover. Then Tasmanian settlers brought dogs to the island, which were far better at killing game than the thylacines were.

Often ignored as one of the main factors for the thylacine’s extinction is the arrival of a mystery disease. This disease was something like canine distemper, and it spread very quickly through the thylacine population. If the thylacines hadn’t been hunted extensively, forced into competition with dogs, and trying to survive in a rapidly fragmenting habitat, the thylacines could have withstood the disease. All of these factors coming at once were too much for any animal.

I wonder if these last thylacines had low genetic diversity. Low genetic diversity could have added another factor that could have made them less likely to survive the epidemic.

We do have a similar case in the Tasmanian devil. In 1995, Tasmania devils started coming down with a horrible cancer. It was discovered that this cancer was transmitted by a parasite.  It is one of those rare transmissible cancers. This disease is called devil facial tumor disease, and it severely disfigures the devil’s face,  which then prevents the animal from feeding. The animal typically dies of starvation. Since it was discovered, it has affected nearly half of the Tasmanian devil population. The Tasmanian devil could actually become extinct because of this disease, so many conservationists are doing all they can to create sanctuaries in which this disease doesn’t exist.

Early settlers killed the devils as readily as they killed the thylacines. Their numbers got quite low before this species was protected by law in 1941. From those days its numbers grew quite rapidly from rather low numbers. The current population of devils is derived from a small number of founders.

Low genetic diversity means that these animals don’t have as much a chance of producing resistant individuals that can survive epidemics. That’s one of the main reasons why genetic diversity matters in wildlife conservation.

Perhaps the thylacine also suffered from low genetic diversity, and it could not withstand the pressures of disease, hunting, habitat distruction, and competition with dogs.

Western man has had a bad record in Australia. Many of its native species could not withstand our encursion into their world. The thylacine was one of these animals. We didn’t take the time to understand them. We took many specimens to zoos throughout the world, but no one ever thought of breeding them. They were a novelty– a great wolf possum from Van Diemen’s Land.

I hope that such an animal still exists in this world, roaming the wilderness and back country of Tasmania. But I don’t hold out much hope.