A System For Cataloguing Thylacine (Tasmanian Tiger) Sighting Reports
The thylacine reports database of over 900 reports can be accessed here.
Although it is officially listed as globally Extinct many people claim to have seen the thylacine since 1936, when the last known individual died in captivity. Reports of its continued existence have not only easily persisted to the present, they have become more numerous over time, leading some to conclude that it's population is increasing. In fact, although only known historically from the island state of Tasmania, reports from the Australian mainland, where the last definite record of the species is about three thousand years ago, significantly outnumber the former. Not to mention the small addition that a number of truly international sightings contributes to that tally, from far flung places like India, the UK and the USA.
Also included amongst the list of nations that the jet-setting thylacine has visited is New Guinea where the species is known prehistorically (van Deusen, 1963; Mountain, 1991). The natives report a living creature called 'dobsenga' or 'dobsegna' which is eerily similar in its description to the thylacine. This is no great biogeographical mystery since the two land masses of Australia and New Guinea were connected until relatively recently when rising sea levels cut Sahul (or Greater Australia) into three distinct geographical areas around 10-14,000 years ago. The biological result of this is that the two areas have significant faunal and floral overlap, which is possibly still being discovered (Helgen et al., 2012; but see Burbidge, 2018).
It wasn't long after European colonisation of Tasmania that the persecution of its inhabitants, the thylacine, the emu, the aboriginals etc., began. And the species' supposed extinction is tentatively dated to 7 September, 1936, when the last known thylacine died a captive in the Beaumaris (Hobart) Zoo1. Just one of a number of mainly large exotic carnivorous animals that were largely neglected as the zoo was in the process of permanently closing. Since then there has been no confirmed record of the species, and with the adoption of the CITES criteria for extinction then accepted (no evidence of a taxon for 50 years), it was declared extinct by both the International Union for the Conservation of Nature (IUCN) and the Australian Government during the 1980's (1982 and 1986, respectively).
Despite the possibility that the species existed in captivity after 1936, it is very likely that the species was extirpated from all but the wild by this time. However, our interest in wild thylacine reports and other alleged signs of the species should actually hark back to pre-1936 times to the last known wild thylacine. Unfortunately the exact date is highly disputed, although it is universally accepted that Wilf Batty specimen shot a specimen in May 1930. The last wild record for which there is a contemporary newspaper report of an actual specimen caught is between 2 and 9 August 1930 (Anonymous, 1930).
I am personally interested in Tasmanian thylacine sightings from about 1910 onwards as the bounties petered out, and thylacines became truly rare creatures indeed. The burning question is, what happened to the thylacine population after this time? Was it already on the inevitable road to extinction, due to inbreeding and/or fragmentation of the population? It has also been hypothesised that some kind of disease contributed to the species' extinction (Paddle, 2000, 2012), although the evidence is rather weak. There is no doubt number of thylacines presented for bounty payments sharply declined in later years. Is it possible that this largely reflected the greater price being paid for living specimens?
As the population grew smaller the genetically deleterious effects of taking out a small number of individuals from the population grew out of all proportion to that when the population was healthy and much larger. So although the persecution virtually ceased, that is no guarantee that the minimal effects of rarely meted persecution didn't have an effect of the same order of magnitude as the bounty schemes did at the turn of the century. We have to face the posibility that the species is extinct. But the huge number of alleged sightings and reports also give us pause. Could they really refer to living thylacines?
The Threat of Hoaxes
In compiling such reports, any researcher or investigator will undoubtedly come upon hoaxes and lies if one persists for any significant length of time. But while they are as persistent as the phenomenon itself, they constitute only a minority of all reports. Most sightings which are reported, and surely virtually all of those not reported, are made by honest individuals. And even if those people are all genuinely mistaken, there is no attempt to mislead anybody. Of course it would be naÏve to suppose that only those making such reports can be hoaxers. In reality, some of the most compelling reports may in fact be hoaxes perpetrated on the innocent witness/es. However, certainly cryptozoological investigators have become adept at spotting lies and deceptions, which acts as an initial filter of such reports that they receive and may then pass on to the wider cryptozoological community.
The Catalogue System
Whoever a thylacine investigator may be, and whatever their motive is, they are interested in the many thylacine reports. There is both a practical and a more theoretical aspect to investigate here. Meeting witnesses and taking statements, recreating reports and all other physical aspects may be covered in a further article. For the present time, however, I am concerned merely to come up with a catalogue system which will help to categorise reports in a manner which lends itself to certain kinds of basic analyses of the reports as a whole. Which I take to be the relevant distinction between practical and theoretical here. For example, one mainland researcher in particular believes that a migratory habit is evident in mainland thylacines, as evidenced by the seasonality of reports from certain areas.
Taking my inspiration from the accession numbers given to museum specimens when cataloguing occurs, I have arrived at a very simple yet effective means of categorising reports by location and date, respectively. As an example, two of the most famous reports are as follows:
TAS.1982.3.10 (Hans Naarding's report; see: Park, 1986:76)
WA.1984.11.xx (the famous Kevin Cameron photographs; see (Douglas, 1986))
Further modifications may be needed because not every report can be given such a specific location/date.
The Social History of the Thylacine
Although the catalogue system lends itself to unconfirmed sightings and reports, allowing an easy way to zero in on potential geographical and seasonal hotspots, there is no reason why it cannot be expanded to include all putative encounters. From prehistoric encounters between the native peoples and thylacines, through to the modern day. In essence, a complete social history of the species.
1 The exact date of the death of the last captive thylacine was fixed by Steven Smith (Smith, 1980). However, one can easily find popular-level authors after 1985 still maintaing that "Benjamin" died in 1933.
Anonymous. (1930). Rare Catch (Waratah.). The Advocate (Tasmania), Monday, 11 August, p. 6.
Burbidge, Andrew A. (2018). Did Zaglossus bruijnii occur in the Kimberley region of Western Australia? Australian Mammalogy 40(2): 315-318. [Abstract]
Douglas, Athol M. (1986). Tigers in Western Australia? New Scientist, 24 April, pp. 44-47.
Guiler, Eric Rowland. (1985). Thylacine: The tragedy of the Tasmanian Tiger. Melbourne: Oxford University Press.
Helgen, K. M., Miguez, R. P., Kohen, J. L. and Helgen, L. E. (2012). Twentieth Century occurrence of the long-beaked echidna Zaglossus bruijni in the Kimberley region of Australia. ZooKeys 255: 103-132.
Mountain, Mary-Jane. (1991). Highland New Guinea Hunter-Gatherers: The Evidence of Nombe Rockshelter, Simbu With Emphasis on the Pleistocene. Thesis submitted for the Degree of Doctor of Philosophy of the Australian National University.
Paddle, Robert. (2000). The Last Tasmanian Tiger: The History and Extinction of the Thylacine. Oakleigh, Victoria: Cambridge University Press. [Google preview]
Paddle, Robert. (2012). The thylacine's last straw: epidemic disease in a recent mammalian extinction. Australian Zoologist 36(1): 75-92. [Abstract]
Park, Andy. (1986). Tasmanian Tiger: Extinct or Merely Elusive? Australian Geographic 1(3): 66-83.
Smith, Steven J. (1981). The Tasmanian Tiger - 1980: A report on an investigation of the current status of the thylacine Thylacinus cynocephalus, funded by the World Wildlife Fund. Hobart, Australia: National Parks and Wildlife Service, 133 pp.
van Deusen, Hobart M. (1963). First New Guinea record of Thylacinus. Journal of Mammalogy 44(2): 279-280.