Thylacine (Thylacinus cynocephalus)
|Also known as:||Tasmanian tiger, Tasmanian wolf|
|Spanish:||Lobo De Tasamania, Lobo Marsupial|
|Size||Tail length: 50 - 65 cm (2)|
Head-body length: 1 - 1.3 m (2)
Shoulder height: 56 cm (7)
|Weight||25 - 35 kg (7)|
Classified as Extinct (EX) on the IUCN Red List 2007 (1).
The thylacine was the largest marsupial carnivore but it is now widely believed to be extinct (1). Despite similarities with canids such as the wolf, the thylacine was extremely distinctive, and the canine appearance was offset by the tapered hindquaters, relatively short legs and broad-based tail (2), which cannot be wagged from side-to-side (7). The short, coarse fur was a dirty yellow-brown with 13 to 19 transverse brown stripes running from the upper back to the base of the tail (3); animals from highland areas had a richer cinnamon-brown coat (7). There were lighter patches of fur (3) surrounding the eyes and near the erect, rounded ears (4). The belly was cream coloured, females carried a backwards-opening pouch (3), and males possessed a pseudo pouch in the form of a fold of skin that protected the testes when moving quickly through low bushland (7). The thylacine was renowned for its ability to open its jaw remarkably wide; whilst it is highly unlikely that this yawn was as wide as is sometimes quoted (180°), the gape was still the widest of any mammal (3), and is surpassed only by that of the snake (7). This species is a classic example of 'convergent evolution'; it is a marsupial mammal that closely resembles the placental canids, especially the wolf from which one of its common names is derived, due to the similarities in their way of life (5).
The thylacine once ranged throughout Tasmania, mainland Australia and Papua New Guinea, although it may have been lost from the latter two locations more than 2,000 years ago (2). It was still widespread in Tasmania at the time of European colonisation but by the early 20th Century had been massively reduced, and in 1930 the last recorded killing of a wild individual occurred (1). The last captive thylacine (known as Benjamin) persisted in Hobart Zoo until 1936, and despite a number of unsubstantiated sightings, the species is now believed to be extinct (3).
Thylacines preferred open forest and grassland (1). As the human population expanded however, thylacines retreated into the more inaccessible hinterland of Tasmania (7).
Very few observational studies were carried out on wild or captive thylacines; we therefore know very little about their natural ecology and behaviour (3). These carnivores are reported to have been mainly solitary and nocturnal (4), although small groups probably consisting of a mother and her offspring have been reported (3). Due to conflicting reports, there is some controversy as to whether breeding occurred more often in the summer or winter. Litters of up to four young were possible due to the four teats within the female's backwards-opening pouch (3). Young remained in the pouch for around four months (7) and then were probably left in a den whilst the mother went on hunting forays; the young may have joined her on these trips when they were older (2).
Thylacines were carnivorous and are likely to have preyed upon kangaroos, small rodents and birds (4). Some reports suggest that these mammals hunted by pursuing their prey over great distances until it tired (3). Thylacines became notorious for killing sheep once European settlers began to farm, a factor that was at the forefront of their persecution. The thylacine is reported to have a fairly stiff gait, but is also believed to have been an agile animal and had been seen standing on its hind legs, supported by its tail in a manner resembling a kangaroo (3).
There is still no conclusive evidence as to what caused the disappearance of the thylacine from mainland Australia, although competition with introduced Asian dogs (dingos) is widely believed to have played a part (3). On the island of Tasmania (where there are no dingos) the thylacine was persecuted to extinction by a long-running eradication campaign (3). The species was widely blamed for many sheep attacks and by the mid 1800s was extensively hunted (3). Between 1888 and 1909, the Tasmanian Government paid bounty for 2,184 thylacine skins (6), although it is likely that the actual number killed during this time was many more. By the early 1900s, thylacines were noticeably rare and the last reported killing occurred in 1930 (1). Other factors such as habitat loss, disease and competition with feral dogs all helped to send this remarkable animal to extinction (4).
In 1938, the thylacine became protected by Tasmanian law and in 1966 a game reserve was proposed (but not enforced) on Maria Island off the east coast of Tasmania, which would have protected any thylacines should they have been captured (7). Unconfirmed sightings of this fascinating marsupial continue to this day, but numerous searches have provided no concrete evidence that the species still exists (5). The UK’s International Thylacine Specimen Database (ITSD), which was released on CD-ROM in April 2005, is a project that has endeavoured to catalogue and digitally photograph (where possible) all known surviving specimen material held within museum, university and private collections around the world. It comprises skins, skeletons, skulls, taxidermy mounts and wet specimens. Wet specimens include four adults preserved in alcohol and ten thylacine pups. The ITSD has been designed as a free access academic tool to promote and facilitate undergraduate and postgraduate research into the species, and helps to forever preserve what little is left (8). Such resources not only facilitate research into this extinct animal, but also serve as an important reminder of the fate that awaits many of our endangered species in the future, should we not do more to protect them now. The thylacine is still an important part of the Tasmanian national conscience and recent talks of the possibility of cloning an animal from DNA preserved in a specimen held at the Australian Museum has sparked massive debate (5). The practicalities of cloning however, and the ethical decisions involved, mean that this possibility is a very long way from becoming a reality (5).
Authenticated (19/11/02) by Col Bailey, Tasmanian Tiger Research and Data Centre.
- Canid: a member of the canidae; the 'dog' family, which includes all living dogs, jackals and foxes.
- Carnivorous: flesh-eating.
- Convergent evolution: when unrelated organisms develop a similar appearance due to their similar way of life.
- Marsupial: a diverse group of mammals characterised by their reproduction. The embryo is born 11 to 35 days after conception. The tiny newborn crawls into the marsupium (pouch) and attaches to a teat where it stays for a variable amount of time. They also differ from placental mammals in their dentition.
- Nocturnal: active at night.
IUCN Red List (June, 2013)