Thylacine controversy

[Overlandman]

From ABC News

http://www.abc.net.au/news/2013-11-15/t ... ection=tas


The mystery of the Tasmanian tiger remains after an expedition failed to catch a glimpse of the elusive animal thought to have become extinct 80 years ago.

The UK-based Centre of Fortean Zoology is dedicated to tracking mythical, mystery and extinct animals around the world.

Nine members have just wound up the first stage of their latest self-funded project: hunting the thylacine.

I've collected nine new sightings that we didn't know of, the most recent was three years ago.
Team member Tony Healy

After scouring Tasmania's rugged north-west, a hot spot for the animal according to the team, expedition leader Michael Williams says he is satisfied with the outcome.

"No we don't have a thylacine in the boot, we don't have anything on camera of any great interest, but it's a roaring success because there's more witnesses than I thought there'd be and there's more areas of interest in a smaller defined area than I thought there'd be," he said.

The last known thylacine died in captivity in the 1930s.

But team member Tony Healy says there is overwhelming anecdotal evidence that suggests it is still out there.
"I was really surprised, I thought people were going to give us the cold shoulder but Taswegians have been really, really friendly and helpful," he said.
"I've collected nine new sightings that we didn't know of, the most recent was three years ago.
"A fellow in his 40s, he'd had two sightings.
"He and a colleague were driving along a logging road during the night and came round a corner and the thylacine was in the middle of the road.
"They both saw it and got a great shock and he said it was clearly thylacine, stripes, the works."
Cryptozoologist convinced Tasmanian tiger still exists
Cryptozoologist Richard Freeman, who's searched for giant anacondas and Mongolian death worms, says the accounts have strengthened his belief.

"Before I came to the island I was 99.9 per cent sure that this animal was still around," he said.

"Now I'm as close you can be without actually seeing one to being utterly convinced that it's still around.

"We've been talking to people like a government-licensed shooter who knows the bush, who goes out into the bush for a living keeping down the number of wallabies; he's seen it twice."

Now I'm as close you can be without actually seeing one to being utterly convinced that it's still around.
Along the journey through the wilderness, Mr Freeman gathered scats he is having analysed.

"They seem to be too large for devil or a quoll and they were in very remote areas, so I'd be very surprised if they were dog," he said.

The team is used to the doubt of sceptics, but they remain committed to the cause.

But Mr Healy says some have a point.

"It does seem strange, almost incredible that one hasn't been run over by now," he said.

The fearless group is departing with a just handful of specimen bottles and tiger tales.

But they've vowed to return in three months to continue the quest to prove the thylacine is Tasmania's best kept secret

[David M]

Supposing it does exist, what then? Catching one would be hard enough but you would need at least one breeding pair and probably quite a few more to breed up a genetically diverse group. And removing specimens from the wild would threaten the diversity of the wild population. Also, like the Devils they might already be so inbred as to be not a viable population.

I think if any are found sperm and ova should be extracted and then the animals tagged with radio collars and then released. The DNA could also be sequenced and the sperm and ova be fertilized and implanted for gestation in a closely related species.

[empireman87]

I believe having done research into the matter that if trying to track the elusive thylacine 8 to 10 people wouldnt work. The animal (if still alive) has adapted to staying well clear of the humans and having a great scence of the land could easily keep out of sight in the south west .... perhaps a 2 to 3 people at the most would have the advantage of perhaps getting on film this incredible marsupial

[Strider]

I saw something while walking on a popular track in central Tasmania about 18 months ago. As I came around a tight corner I startled a large animal of some description. All I saw of it was the dark, thin end of a tail 2 metres or so away from me, but what really got me wondering was that it when it took off into the surrounding scrub it did so with complete silence. I wonder...

Sent from my SM-N9005 using Tapatalk

[Kainas]

Reminds me of the old guy I met in a backcountry hut in Fiordland... He was looking for Moose. Fascinating story about how Queen Elizabeth (or Victoria??) gave 6 moose to someone in NZ, and they were released in Fiordland.

Half a century later there is this dedicated group of old guys who set up hides, cameras, and spent half their lives in the backcountry looking for signs of these moose, or their progeny.

[Gadgetgeek]

David, my understanding is that the Thylacine was the end of its evolutionary branch as it where, with no close relatives at all. This leads me to believe that such a specialized animal would either really quickly return to its former numbers, or go extinct. With other species there is always the chance of cross breeding or other plausible explanations for sightings, but in this case, I just don't think it would be possible.

Personally I think the thylacine should be held up as an example of an animal that we exterminated without good cause, and could have learned a lot from, and maybe get people understanding that we need to spend a lot more time studying wildlife, since we haven't progressed as much as people think we have. If treating it like a cryptid, and supporting a tourism based research program works, then we should do that. We just don't know how many more of those sorts of mistakes we can make.

[MickyB]

Personally I think the thylacine should be held up as an example of an animal that we exterminated without good cause

I don't think humans are solely to blame for the Thylacine going extinct (although I do agree with everything else you have said). I think disease might have had a lot to do with it as well.

[north-north-west]

Personally I think the thylacine should be held up as an example of an animal that we exterminated without good cause

I don't think humans are solely to blame for the Thylacine going extinct (although I do agree with everything else you have said). I think disease might have had a lot to do with it as well.

A disease that may have been introduced by the colonists?

If you look at the number of claims on the bounty, there's probably not much doubt as to the impact of colonisation on the Thylacine. Indiscriminate shooting caused the extinction of species with massively higher populations - look at the passenger pigeon and Carolina parakeet, for instance.

[MickyB]

Personally I think the thylacine should be held up as an example of an animal that we exterminated without good cause

I don't think humans are solely to blame for the Thylacine going extinct (although I do agree with everything else you have said). I think disease might have had a lot to do with it as well.

A disease that may have been introduced by the colonists?

If you look at the number of claims on the bounty, there's probably not much doubt as to the impact of colonisation on the Thylacine. Indiscriminate shooting caused the extinction of species with massively higher populations - look at the passenger pigeon and Carolina parakeet, for instance.

'Only' 2184 bounties were paid. Even if ten times that many Thylacines were shot (without the bounty being claimed) then in total less than 22,000 were killed by humans (diseases introduced by humans aside). 22,000 is not many when you consider the Tasmanian Devil population has been reduced to approx 15,000 - 50,000 individuals as a result of DFTD. Obviously shooting the Thylacines had a huge impact on their numbers but I don't think it is solely to blame for their extinction.

[icefest]

'Only' 2184 bounties were paid. Even if ten times that many Thylacines were shot (without the bounty being claimed) then in total less than 22,000 were killed by humans (diseases introduced by humans aside). 22,000 is not many when you consider the Tasmanian Devil population has been reduced to approx 15,000 - 50,000 individuals as a result of DFTD. Obviously shooting the Thylacines had a huge impact on their numbers but I don't think it is solely to blame for their extinction.

That's the government bounties between 1888 and 1909. What about the bounties by Van Diemen's Land Company which were introduced in 1830, almost 50 years earlier?

[MickyB]

'Only' 2184 bounties were paid. Even if ten times that many Thylacines were shot (without the bounty being claimed) then in total less than 22,000 were killed by humans (diseases introduced by humans aside). 22,000 is not many when you consider the Tasmanian Devil population has been reduced to approx 15,000 - 50,000 individuals as a result of DFTD. Obviously shooting the Thylacines had a huge impact on their numbers but I don't think it is solely to blame for their extinction.

That's the government bounties between 1888 and 1909. What about the bounties by Van Diemen's Land Company which were introduced in 1830, almost 50 years earlier?

Yep. Sorry icefest - I did forget about that bounty. I couldn't find any info on how many bounties were paid out by them however I did find the following: Between 1878 and 1909 a total of 4,821 Thylacines were slaughtered. http://www.tasmaniantimbers.com/thylacine.html I assume that number is only the known ones. Even if you quadrupled that number for that period (less than 20,000) and quadrupled it again for the period of the Van Diemen's Land Company bounties until 1878 (80,000) that is a total of 100,000 animals in 79 years. Surely a lot more Thylacines existed over that period of time.

[icefest]

'Only' 2184 bounties were paid. Even if ten times that many Thylacines were shot (without the bounty being claimed) then in total less than 22,000 were killed by humans (diseases introduced by humans aside). 22,000 is not many when you consider the Tasmanian Devil population has been reduced to approx 15,000 - 50,000 individuals as a result of DFTD. Obviously shooting the Thylacines had a huge impact on their numbers but I don't think it is solely to blame for their extinction.

That's the government bounties between 1888 and 1909. What about the bounties by Van Diemen's Land Company which were introduced in 1830, almost 50 years earlier?

Yep. Sorry icefest - I did forget about that bounty. I couldn't find any info on how many bounties were paid out by them however I did find the following: Between 1878 and 1909 a total of 4,821 Thylacines were slaughtered. http://www.tasmaniantimbers.com/thylacine.html I assume that number is only the known ones. Even if you quadrupled that number for that period (less than 20,000) and quadrupled it again for the period of the Van Diemen's Land Company bounties until 1878 (80,000) that is a total of 100,000 animals in 79 years. Surely a lot more Thylacines existed over that period of time.

I don't know enough to know whether the shooting was the cause. Thomas et al in 2006 estimated the pre-european population to be between 2000 and 4000 with a maximum growth rate of 0
.3405. At that size and growth rate shooting could potentially have an impact. http://onlinelibrary.wiley.com/doi/10.1 ... .12029/pdf

[MickyB]

Thomas et al in 2006 estimated the pre-european population to be between 2000 and 4000

If this is correct perhaps they were destined for extinction even if Europeans didn't arrive.

[north-north-west]

... that is a total of 100,000 animals in 79 years. Surely a lot more Thylacines existed over that period of time.

We don't know. That's the problem.
We don't know how many there were, how their removal has affected the island's ecosystems, how much effect colonisation had on their disappearance . . . we really just don't know. All we can say for sure is that colonisation certainly didn't help their chances of survival.

[vicrev]

Thomas et al in 2006 estimated the pre-european population to be between 2000 and 4000

If this is correct perhaps they were destined for extinction even if Europeans didn't arrive.

Destined for extinction ????...they certainly were......they lived in harmony with other now, or, near extinct life forms, for thousands of years,once the European settlement,or some say occupation happened, that sounded the death knell for Fauna as it was up until that time...........it is still happening,we really haven't learnt much........

[Gadgetgeek]

NNW, I agree with your point that we don't know, and that's one of the reasons I think more people should know about it. MickyB, the hardest part of making those estimates is that it would be impossible to know how much those deaths disrupted the population. Not only gestation and birth-rate but there are other factors, some animals don't do well with parent loss, we don't really know how important that was, others get extra stressed by range changes, or when population ratios get really weird. male grizzly bears are much more likely to predate cubs when the male ratio is too high, or kill loaner young males, where as when there is more balance they are more chill. Not saying that is what happened, or that you are wrong, just that bounty numbers are a pretty tough stat to start from.

[MickyB]

I do totally agree that shooting Thylacines would have had a huge impact on their numbers. I just think that it can't be solely to blame to their extinction and disease might have played a small role. Of course this is just my opinion and I could be totally wrong.

there are other factors, some animals don't do well with parent loss, we don't really know how important that was, others get extra stressed by range changes, or when population ratios get really weird.

That is a very interesting point Gadgetgeek and something I had never really thought about. I have read somewhere that Thylacines could drop dead from apparent shock when captured by humans. Perhaps they were an animal that could not handle stress so the points you made may have had an impact.

[north-north-west]

That is a very interesting point Gadgetgeek and something I had never really thought about. I have read somewhere that Thylacines could drop dead from apparent shock when captured by humans.

Stress myopathy is quite common amongst some marsupial species, although generally more with the herbivores.

[Gadgetgeek]

White tail deer are prone to it, one of the reasons that they didn't do well as a farmed species. Elk do much better, but since they are a herding animal, and much larger, the handling is a greater challenge.

[stry]

While we are exchanging guesstimates of likely population levels, it would be helpful to remember that the thylacine was at the top of the Tasmanian food chain.

As such, the maintenance of a viable population would have required far fewer thylacines than those animals below the thylacine in the population pyramid. A few thousand may well have been a balanced and viable population.

The same is true of such top predators as lions, tigers, and many bear species.

[empireman87]

I agree with most of the posts on this photo. The animal is to small and stripes aren't spaced out quite like the thylacines are.

[Travis22]

http://www.heraldsun.com.au/leader/sout ... 7431009385


Travis.

[SDB]

As causes for presumed extinction, don't forgot:
- habitat clearing
- 1080 baiting
From all the evidence I suspect that Tasi Tigers survived long after the 1930's, but the more recent extensive 1080 baiting program is likely to have wiped them out. I'm not suggesting that there was another easy answer to the fox problem, but ultimate extinction of the Tiger is probably an unfortunate consequence.
Mainland populations were probably doing just as well as in Tasmania following the suspected release of 6 breeding pairs in around 1910 up until the 1080 baiting program kicked off in the early to mid 1990's. There have been a significant reduction in Victorian sightings since this time with almost none after the mid 2000's around the suspected release area.
There could be a simple solution to allow continued 1080 use, but still allow protection of any Tasmanian Tiger populations based on the larger jaw size of the Tiger compared to the fox, but possibly it is too late already...