The Thylacine: Distinction in Extinction

From the book Atlas de Zoologie: ou collection de 100 planches by Paul Gervais, 1844

The thylacine (Thylacinus cynocephalus) was first described in 1808 by George Harris (note that the illustration above refers to the animal as Thylacinus Harrisii). Also known by the common names Tasmanian tiger and Tasmanian wolf, the thylacine had a canid like appearance and is known for its unusually wide gape of the jaws.

The last living thylacine, photographed with the jaws wide open, at the Beaumaris Zoo in Hobart, 1933. (Image: Wikimedia Commons)

Thought to be a mostly nocturnal animal, thylacines likely hunted alone and ambushed their prey, unlike wolves which hunt in packs and are pursuit predators. Thylacines were marsupials and at one time lived throughout Australia but disappeared from the mainland several thousand years before European settlers arrived. The population was then restricted to the island of Tasmania.

(image ZSL)

In May 1850, London Zoo became the first major zoo to exhibit thylacines after receiving a juvenile male and juvenile female. They were painted by Joseph Wolf.

Thylacinus Cynocephalus Juv. by Joseph Wolf, 1850

The male died three years later. London Zoo exhibited eighteen more thylacines over the years. A male purchased in 1884 died in February 1890 and was the subject of a scientific article by Frank E. Beddard, Prosector to the Society, in which Mr. Beddard states he was “greatly surprised” to find the male had a pouch. The small pouch served as a sheath for the reproductive organs, not to carry young.

Mr. Smit’s sketch of a male thylacine’s pouch from the article “On the Pouch and Brain of the Male Thylacine” by Frank Evers Beddard, included in the book Proceedings of the Zoological Society of London, 1891

The last thylacine at the London Zoo, a female, died in 1931.

Thylacine at London Zoo (image ZSL)

Although many zoos, menageries and circuses exhibited thylacines, the animal did not thrive in the small, barren cages of the era. Zoos failed to develop a captive breeding program and no definitive records exist of any thylacines born in zoos.

Not an entirely accurate depiction of a thylacine appearing in the book The Naturalist’s Library Volume XXIV, Mammalia: Marsupialia, or Pouched Animals by GR Waterhouse, 1866
A more vibrantly colored version of the same rendering from A Hand-book to the Marsupialia and Monotremata by Richard Lydekker, 1896
Two images from the book The Royal Natural History by Richard Lydekker, 1893

Most every book which includes an entry on the thylacine while extant makes mention of the animal preying upon sheep and thus being targeted by farmers (examples above and below). In The Mammals of Australia (1871), Krefft states that reports from shepherds indicate a single thylacine could quickly kill hundreds of sheep and that men had been attacked too. He goes so far as to say if hungry enough, the thylacine would kill a cow or horse.

Lovely artwork appearing in the book The Mammals of Australia: Illustrated by Miss Harriett Scott, and Mrs. Helena Forde, by Gerard Krefft, 1871

The ferocity and particularly the sheep predation were widely held beliefs, or at least widely shared stories.

Two photos and an excerpt from The Book of the Animal Kingdom by William Percival Westell, 1910
Photo and excerpt from the book Popular Official Guide to the New York Zoological Park by William Temple Hornaday, 1909
Excerpt on Thylacines from the book Natural History in Zoological Gardens by Frank Evers Beddard, 1905

Science has since determined that thylacines were likely incapable of killing a sheep (or hundreds of sheep), let alone a cow or horse. Their jaws were too weak. A 2007 study found that a thylacine’s skull might have broken apart had the animal attempted to take down prey larger than a possum or small wallaby. Another study in 2011 resulted in similar findings. The thylacine’s inability to prey upon larger animals along with its dense body type which required a substantial amount of food limited its ability to adapt when European settlers began taking habitat from thylacines, their prey and every other native animal.

Despite the absence of evidence, thylacines were hunted as flock predators. The first colonial farms were established in Tasmania in the early 1800s and within a few decades, farmers were paying bounties on thylacine skins. In 1888, the Tasmanian government joined in, paying one pound per dead adult thylacine and ten shillings for dead joeys. More than 2180 bounties were paid over the course of the 21 year program. Humans killed an estimated 3500 of the estimated 5000 thylacines living in Tasmania at the time European settlers arrived. The last known killing of a thylacine in the wild was in 1930.

Male thylacine at Beaumaris Zoo in Hobart, circa 1936

The last captive thylacine was locked out of his indoor shelter at the zoo in Tasmania in September 1936 and died of exposure during the night. The government had just granted full protection to the species two months earlier.

Thylacine watercolor by Ethel Anna King (1879 – 1939)

A 1938 expedition attended and summarized by M. S. R. Sharland of the Royal Zoological Society of New South Wales reported thylacine footprints, but no live sightings, in remote areas of western Tasmania. It was thought by expedition members that this mountainous region, inhospitable to agriculture, harbored the last living thylacines. Concern was expressed that the government had recently built a major road through it, further endangering the tiny population.

Photo by A. F. Basset Hull included in Sharland’s summary of the 1938 expedition searching for thylacines, from the book Proceedings of the Royal Zoological Society of New South Wales, 1938 – 1939.

In 2017, researchers published findings that the thylacine suffered from extremely low genetic diversity and had for roughly 100,000 years. This would have made the last thylacines highly susceptible to disease at the time European settlers and their dogs came to Tasmania. The significance of this has been debated and a 2013 mathematical model showed that the actions of humans alone were enough to cause the extinction of the species. However Robert Paddle makes a compelling case in his 2012 paper that marsupi-carnivore disease must have a place in thylacine extinction theories:

In hindsight, without the disease, unquestionably a continuation of the unfettered habitat destruction,
environmental degradation and the deliberate targeting of the thylacine as a pest, would have pushed the species to extinction. It just would have taken a significantly longer period of time, and the chance of saving the species, through changing public opinion, and the re-establishment of captive breeding, could have been possible. But the marsupi-carnivore disease, with its dramatic effect on individual thylacine longevity and juvenile mortality, came far too soon, and spread far too quickly. As such, this epidemic disease demands recognition, alongside habitat destruction, environmental
degradation and deliberate killing, as the final causative straw that broke the thylacine’s back.

While the thylacine was officially declared extinct in 1986, the actual date of extinction is unknown and likely to be debated and investigated repeatedly. A paper from January 2021 posited a range of extinction dates “with the peak likelihood centered on the late 1980s to early 2000s.”

In 2020, rediscovered footage, less than a minute long, was released showing the last known living thylacine at the Beaumaris Zoo in Hobart, Tasmania in 1935. I find it difficult to watch as it shows the animal pacing on concrete while people violently bang on the chain link enclosure, right in his face.

With the arrival of European settlers in Tasmania, the thylacine may have been on a path to extinction due to multiple factors including habitat loss, high disease susceptibility and low ability to adapt to changes in prey availability. The next 100 years would have been our chance to possibly save the species. We did not.

Beautiful illustration by Helmut Diller (1911 – 1984)

Whatever other factors besides humans contributed to the extinction of the thylacine, two things haunt me:

1. Collectively we made no meaningful effort to save the thylacine and in fact caused harm when we knew the population and chances for species survival were dwindling.

2. When we knew there was just one thylacine left, we put him on display in a cage, taunted him for the camera and killed him with neglect.

We own that. I think the regret and shame we feel over the extinction of the thylacine are primary drivers in the emotional investment we have in believing, or wanting to believe, reports of recent live sightings. But a lack of hard evidence indicates the hope of thylacines living today is just a hope which, in itself, is a good thing, provided we maintain sound judgement. And if that hope causes us to better appreciate the inherent sanctity and connectedness of all life, perhaps it can inspire us to choose to do better in future.

Further reading: If you really want to get into the weeds, visit The Thylacine Museum, an online treasure trove of all things thylacine.

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