(page 1)

.Sydney Morning Herald of the 2nd Feb 1937 (p.13).
    "Unless something is done, and done quickly, one of the most interesting survivals from the past still living on this earth will quickly follow the Quagga into extinction".
The Queenslander newspaper, 25th Feb. 1932 (p. 43),
quoting G. W. Morey writing in "The Field".
    "The trackless, uninhabited areas of Western Tasmania, where the serried tops of high ranges rise like the teeth of some gigantic crosscut saw, and the intersecting valleys are filled with brown button-grass or densely-matted rain forest scrub, the remnant of a fast disappearing, primitive animal manages still to find a living.  It is a rather precarious existence, because the small game on which it feeds is none too common, and sheep, which, since the first days of white settlement provided it with food, are far removed from this inhospitable territory in which it has been driven, to make its last stand".
Sydney Morning Herald, 2nd Feb. 1937 (p. 13),
TASMANIAN TIGER: Marsupial's Stand, by M. S. R. Sharland
    On the night of the 7th September 1936, the last known captive thylacine died at the Beaumaris Zoo on the Queen's Domain in Hobart, Tasmania.  It has been argued that this was the "extinction event", and that this young male represented the last of his kind.  Dr. Bob Paddle, in his book "The Last Tasmanian Tiger", is a proponent of this position.  The alternate viewpoint, championed by the
late Dr. Eric Guiler (Australia's leading authority on the thylacine), and more recently by Sleightholme & Campbell (2015), argues that this was not the case, and provide evidence to support the view that the species survived well beyond Benjamin's demise.

    Extinction is a difficult event to detect, even in well known taxa such as mammals.  The extinction of an animal species occurs when the last individual member of that species dies, although the capacity to breed and recover may have been

Beaumaris Zoo (SB) - circa 1917-1921
A reclining thylacine at the Beaumaris Zoo (SB).  This photo was taken sometime between 1917 and 1921, by Miss D. O. Park.
lost long before this point.  Species become extinct when they are no longer able to survive in changing conditions, or against superior competition.  A species may become functionally extinct when only a handful of individuals survive, which are unable to reproduce due to sparse distribution over a large range, or a lack of individuals of both sexes.  Although a species may be deemed "extinct in the wild", the species is not extinct until every individual, regardless of location, captivity, or ability to breed, has died.  Because a species's potential range may be very large, determining the date of extinction is generally undertaken retrospectively.
    The "Red List of Threatened Species", published by the International Union for the Conservation of Nature (IUCN), classified the thylacine as being extinct in 1986 (McKnight 1986).  Prior to 1995, the IUCN deemed a species to be extinct if it had not been seen or recorded in the past fifty years.  This precept has now changed, with the focus shifting from that of time lapse to exhaustive survey:

    "A taxon is extinct when there is no reasonable doubt that the last individual has died.  A taxon is presumed extinct when exhaustive surveys in known and / or expected habitat, at appropriate times (diurnal, seasonal, annual), and throughout its historic range have failed to record an individual.  Surveys should be over a time frame appropriate to the taxon's life cycle and life form". 

    By comparison, the IUCN definition of critically endangered is:

    "A category containing those species that possess an extremely high risk of extinction as a result of rapid population declines of 80 to more than 90 percent over the previous 10 years (or three generations), a current population size of fewer than 50 individuals, or other factors". 

    We shall now examine the factors that contributed to the thylacine's decline and explore the evidence to countenance the view that the thylacine became extinct in 1936.

   In Tasmania, the thylacine was protected by the natural barrier of the Bass Strait from the competitive forces that decimated its former range on the Australian mainland.  These competitive forces have been linked with competition from the placental dingo (Canis lupus dingo), climatic change, and disease.

    Guiler estimated that the total thylacine population at the time of British settlement (1803) as being around 2000-4000 individuals.  Guiler (1998, p. 138) states:

    "Some parts of Tasmania did not support many, if any thylacines.  The rain forests and sagelands, which account for almost half the surface area of the State, were not favoured tiger habitat.  If this area is subtracted from the total area of the State, then the average home range of tigers in Tasmania would be reduced by about one half.  The Woolnorth estimates suggest a home range per individual or pair of between 50 and 60 square kilometres, which would indicate a Tasmania wide thylacine population between 1357 and 1138 individuals, or double these two figures (between 2714 and 2276) if each home range sheltered a pair of tigers.  Home ranges of less than 25 square kilometres would not have provided sufficient space for adequate food, shelter, breeding dens and other elements necessary to thylacine survival.  Therefore, the conclusion is made that there were between 2000 and 4000 thylacines living in Tasmania in any one year, and would have been less rather than more".

   All parties on either side of the extinction / survival debate now agree that a significant collapse in thylacine numbers occurred during the first decade of the twentieth century.  Sleightholme & Campbell (2015) cite several factors as being responsible or contributing to this demise:

- The bounty schemes - Wild animal trade
- Disease - Hunting and the fur trade
- Habitat destruction - Trade in thylacines for museums
- Feral dogs

    An examination of each of these factors to assess its potential effect on thylacine numbers is therefore warranted.

back to: Expeditions and Searches (page 13) return to the section's introduction forward to: Extinction vs. Survival (page 2)

Search the Thylacine Museum
Site Map
Website copyright © C. Campbell's NATURAL WORLDS.
Photographs and other illustrations (where indicated) are © C. Campbell's NATURAL WORLDS.
Other photos and images are © their respective owners.