Joined: 12 Oct 2006
|Posted: Sun Oct 15, 2006 3:49 pm Post subject: Thylacine
|The Thylacine (Thylacinus cynocephalus) is a large carnivorous marsupial native to Australia which is thought to have become extinct in the 20th century.
Locally, it is known as the Tasmanian Tiger or Tasmanian Wolf, and colloquially the Tassie ("tazzy") Tiger or simply the Tiger.
Although it is only one of many Australian mammals to have become extinct following European settlement of the continent, it is the largest and by far the most famous.
Like the tigers and wolves of other continents (both placental carnivores and therefore not closely related to the marsupial Thylacine), the Thylacine was a top-level predator, and in size and general form quite closely resembled the Northern Hemisphere predators it was originally named after.
Taxonomy and evolution
Reconstruction of Thylacinus potens, one of the Thylacine's larger also extinct relativesFossils of Dickson's Thylacine (Nimbacinus dicksoni), the oldest ancestor of the Thylacine, found in Riversleigh, Australia date back 23 million years ago, during the Miocene epoch. This thylacinid was much smaller than its more recent relatives. The largest species was Thylacinus potens from the late Miocene, which grew to the size of a wolf. In late Pleistocene and early Holocene times, the Thylacine was widespread on the Australian mainland.
The animal was rare (and by today's standards vulnerable) even when the first Europeans arrived in Tasmania. It was first described in 1808, 5 years after first settlement of the island. They numbered as little as 3,000 at first settlement, with the heaviest distributions in the North East, North West and North Midland regions. From the early days of European settlement they were rarely sighted even at their largest numbers.
Physical descriptions of the Thylacine vary since the first sighting of the animal. Evidence is restricted to preserved pup specimens, fossil records, skins of the animal, photographs and video of the animal in captivity and anecdotal evidence.
The Thylacine resembled a large, short-haired dog with a stiff tail, which smoothly extended from the body like that of a kangaroo. Many European settlers drew direct comparisons with the Hyena and written testimonies often used this term for the animal, due to its unusual stance and general demeanor. (Guiler)
Size and Characteristics
The mature Thylacine ranged from 100 to 130 cm long, including a tail of about 50 to 65 cm. The Thylacine's yellowish-brown coat featured sixteen to eighteen distinctive dark stripes on its back and rump. The stripes earned the animal the nickname "Tiger".
Like other marsupials, the Thylacine had a pouch, but unlike many other marsupials, the pouch opened to the rear of its body. In at least two male specimens a scrotal pouch, unique amongst marsupials, was also documented.
One unusual feature of the Thylacine was the ability to open its jaws to a surprising extent. Although it is most unlikely that the gape was as wide as some reports have stated (~180°), it was still the widest of any known mammal. This capability is captured in part of a short black-and-white film sequence dating from 1936 which shows a captive Thylacine in a zoo.
Thylacines footprints can be distinguished from other animals. Unlike foxes, cats, dogs, wombats or devils, Thylacines have a very large rear pad and four front pads, almost in a straight line. (Guiler)
Like their relative the Devil, the tiger is believed to have possessed an acute sense of smell which enabled it to track prey for many miles.
Those that saw the animal in the wild are said to have described it having a strong and distinctive smell. It is possible that the animal, like its relative the Tasmanian Devil, gave off a smell when agitated.
Motion & Vocalisations
The Thylacine was often observed as having a stiff and somewhat awkward gait, making it unable to run at high speed. A suprising feature of the animal was its ability to execute a bipedal hop, in a similar fashion to a kangaroo, which it demonstrated at various times during captivity. This also enabled the animal to balance on its hind legs and stand upright for brief periods. Guiler speculated that it was used as an accelerated form of motion when the animal became alarmed. Although, like the unusual gape, the purpose of this ability is not known. Although there are no recordings of the Thylacine's vocalisations, observers of the animal in captivity noted that the animal would growl when angry and emit a series of rapidly repeated guturral cough like barks (often described as a "yip-yap" or "cay-yip" sound) during hunting.
Ecology and behaviour
Surprisingly little is known about the behaviour or habitat of the Thylacine. A few observations were made from captivity, but only limited or anecdotal research of the animal in the wild.
It is said that the Thylacine preferred to inhabit dry eucalyptus forests, wetlands, and grasslands in continental Australia. Fossils dating back 2,200 years ago and Indigenous rock paintings indicate that the Thylacine lived throughout mainland Australia and New Guinea. A mummified carcass was discovered in a cave in the Nullarbor Plain in Western Australia, dated to around 3,300 years old provided physical proof of the animal's existence on the mainland.
Scientists generally believe it became extinct in mainland Australia about 2000 years ago (and possibly earlier in New Guinea) attributed to competition from invasive Dingos. Evidence to this effect comes through the discovery of Thylacine fossils in close proximity to Dingo fossils. It is believed that the two species may have even fought for the same prey. Other researchers point to indigenous humans, who adopted the Dingo as a hunting companion, as playing a part in the mainland extinction.
In Tasmania it preferred the woodlands of the midlands and coastal heath, which became the primary focus of British settlers seeking grazing properties for their cattle.
Early observers noted that the animal was typically shy and secretive, with an awareness of the presence of humans and generally avoiding contact, although the animal was noted to sometimes show inquisitive traits. This sometimes led to the animal being branded as "cowardly".
Like the Tasmanian Devil and its marsupial prey, the Thylacine was a nocturnal and crepuscular hunter, spending the days in a nest of twigs and bark in small caves or hollow tree trunks. It typically retreated to the hills and forest during the day for shelter and hunted in the open heath at night.
The animal had a typical home range of between 40-80 square kilometres.
Breeding season was in winter and spring and a female would produce up to 4 cubs (typically 2 or 3 per litter), carrying the young in a pouch for up to 3 months and protecting them until at least half grown. Despite numerous attempts by zookeepers, Thylacines never bred in captivity.
The Tasmanian Tiger ate a variety of foods but mainly meat because it was a carnivore. Analysis of the skeletal frame and observation in captivity points to it singling out a target animal and doggedly pursued the target until it was exhausted. Although some studies conclude that the animal may have hunted in small family groups, with the female herding prey in the general direction of a male waiting in ambush before utilising a powerful lunge with its open jaw.
Prey included kangaroos, wallabies, birds and various small animals such as wombats and possums. Guiler notes that a favourite prey may have been the once extensive Tasmanian Emu, a large flightless bird which shared the habitat of the Thylacine and hunted to extinction in 1850 by Europeans, possibly coinciding with a decline in Thylacine numbers. Both Dingos and foxes have been noted to hunt the emu on the mainland and some go further to postulate that the mature Thylacine's jaw and bipedal hop were specialised for hunting the emu and either breaking its neck or severing the jugular vein.
After European settlement the Thylacine was believed to have also opportunistically preyed upon farmers' sheep and poultry. In captivity, Thylacines were fed dead rabbits and wallabies, which they devoured entirely, as well as beef and mutton.
Tasmania, where there were no Dingos, the Thylacine survived until the 1930s before it went extinct in captivity. The extinction is popularly attributed to the relentless efforts of farmers, Tasmanian government and privately-funded bounty hunters (with over 2,000 scalps officially taken between 1888 to 1912) and, in its final years, collectors for overseas museums. However, in reality there were most likely multiple factors, including competition with wild dogs (introduced by settlers) and a distemper-like disease (that also affected many captive specimens at the time) which was believed to have led to a sharp drop in the population around 1908, when far fewer bounties were taken. Also, there are reports of Thylacines being killed for their hides, which were then exported to other countries. Since the animal was never very numerous to begin with, these multiple pressures could have easily pushed the population from endangered, to critically endangered, to a possible tragic extinction.
In any case, the animal had become extremely rare in the wild by the late 1920s. There were several efforts to save the species from extinction. Records of the Wilsons Promontory management committee dating to 1908 included recommendations for Thylacines to be reintroduced to several suitable locations on the Victorian mainland. No existing records state whether or not this recommendation was actually carried out If it was, it might be the source of thylacine sightings on the Australian mainland, since they had been extinct there for several thousand years In 1928, the Tasmanian Advisory Committee for Native Fauna had recommended a reserve to protect any remaining Thylacines, with potential sites of suitable habitat including the Arthur-Pieman area of western Tasmania.
Farmer Wilf Batty shot and photographed the last known wild Thylacine (believed to be a male) in 1930 in Mawbanna, in the North East of the state.
The last captive Thylacine, captured in 1933 and referred to as Benjamin (although it was most probably a female specimen) later died in the Hobart Zoo on 1936-09-07 (now known as Threatened Species Day in Australia). She is believed to have died from neglect, suffering exposure to the cold and no access to sheltered sleeping quarters. A short black-and-white film was made of the captive pacing back and forth in its enclosure. The photographer, the naturalist David Fleay, was bitten on the buttocks whilst taking the photograph.
Official protection of the species by the Tasmanian government was belatedly introduced in 1938.
The results of various subsequent searches indicate a strong possibility of survival of the species in Tasmania into the 1960s. Searches by Dr. Eric Guiler (considered a leading authority on the species) and David Fleay in the north-west of Tasmania found possible footprint and scats and heard presumed vocalisations as well as anecdotal evidence from people presumed to have sighted the animal. Despite the searches, no conclusive evidence was found to point to continued existence.
The Thylacine held the status of "endangered species" until 1986, when it was declared extinct by international standards. That standard states that any animal that has not been proven to exist for 50 years is declared extinct. Since no definitive proof of the thylacine exists since "Benjamin" died on September 7, 1936, the thylacine sadly now met that official criteria.
Although the Thylacine is formally extinct, many people believe the animal still exists. Sightings of this cryptid are regularly claimed in both Tasmania, other parts of Australia and even Indonesia in the Irian Jaya area, near the New Guinea border. Thylacine researchers Buck and Joan Emburg of Tasmania report 360 Tasmanian and 269 mainland post-extinction 20th century sightings whilst the Australian Rare Fauna Research Association reports 3800 mainland sightings on file
Of the mainland sightings, by far the most frequent, along with the Gippsland phantom cat, are in the Gippsland region of southern Victoria. There have been several alleged photos produced as evidence, but many of these are believed to have been feigned.
In contrast, sightings of the Red Fox (first introduced as early as 1864 and later around 2000) in Tasmania are taken very seriously. This is despite only minimal evidence (4 carcasses, a scat sample and possible footprints since 2001) of the species existence in the state. While the Fox Free Tasmanian Taskforce receives continued government funding, all funding for the searches of the indigenous Tasmanian Tiger has ceased. The elusiveness of the fox in the vast Tasmanian wilderness gives some hope of the continued existence of the Thylacine.
Despite many sightings being instantly dismissed, some alleged sightings have generated a large amount of publicity. In 1982 a researcher with the Tasmanian National Parks and Wildlife Service, Hans Narding, observed at night what he believed to be a Thylacine for three minutes at a site near Arthur River in the state's North West. The sighting began an extensive year-long government-funded search.
In January 1995, a Parks and Wildlife officer reported observing a Thylacine in the Pyengana region of North Eastern Tasmania in the early hours of the morning. No trace of it was found.
In 1997, it was reported that locals and missionaries near Mount Cartenz in Irian Jaya had sighted thylacines (where dingoes are now rare if not extinct) and had known about about them for many years but had not made an official report, initiating a full investigation. The local people reported that animals resembling the Thylacine was raiding their livestock.Since this region is remote and not easily accessible to outsiders, as well as dangerous due to some fighting in the area, it is still not known as of October, 2006 if these attacks were carried out by Thylacines or wild dogs.
In February 2005 Klaus Emmerichs, a German tourist, claimed to have taken digital photographs of a Thylacine he saw near the Lake St Clair National Park, but the authenticity of the photographs has not been established. The photos were not published until April 2006 (and then, only in Tasmania and Europe), fourteen months after the sighting. Prior to this the Sydney Morning Herald's photographic managing editor Mike Bowers produced a deliberately feigned image which demonstrated how easily a feigned image could be produced. This may have also been in response to Emmerichs' claim that his photos were stored on the internal memory chip of his Ricoh camera as Ricoh has since confirmed that the photos cannot have been uploaded from externally
In 1984, Ted Turner offered a $100,000 reward for proof of the continued existence of the Thylacine. However, a letter sent in response to an inquiry by Thylacine-searcher Murray McAllister in 2000 indicated that the reward had been withdrawn.
In March 2005, Australian news magazine The Bulletin, as part of its 125th anniversary, offered a $1.25 million reward for the safe capture of a live Thylacine. When the offer closed at the end of June 2005 no one had produced any evidence of the animal's existence. An offer of $1.75 million has subsequently been offered by a Tasmanian tour operator, Stewart Malcolm, but this is also unclaimed.