My impression is that Tasmanian Tigers live (or lived) in family groups and that there would also be solitary animals.

If we consider the types of grouping we might expect for a dog-shaped animal, we might then be able to consider whether it applies to the Tasmanian Tiger, or Thylacine (Thylacinus cynocephalus).

Firstly, most of us would be familiar with the Northern Hemisphere’s wolves living in packs. Such packs may number into a dozen or dozens of animals - each with a role within the pack. There is nothing in historical literature to suggest the Tasmanian Tiger - also sometimes called the Tasmanian Wolf - ever formed packs in the manner of the placental wolves of the northern hemisphere.

Next would be to consider smaller groupings - such as a family unit. There are some historical accounts - in particular, referenced by Col Bailey in his re-telling of “Tiger Tales” told to him by “old timers” that had first-hand experience with the species (trapping, etc) before the 1930s - that talk about Tasmanian Tigers hunting co-operatively. By some accounts, some tigers (two, say) would pursue a prey animal, such as a wallaby. Tigers were said to have excellent stamina, if not direct speed, so they are sometimes described as “pursuit predators” - “doggedly” pursuing prey until the prey animal collapses.

In any case, the description of a hunt has these two or so “chasers” pursuing a wallaby or mob of wallabies, and they would gradually steer the chase into a wide arc. For example, they might continually align themselves toward the left side of the prey animal so as to guide the animal to veer off toward the right.

In the meantime, others of the family unit would actually cut across this wide arc in a direct line - and therefore be ready to intercept the wallaby or prey animal as it came past, being pursued by those chasers.

If this account is correct then it suggests at least two tigers hunting co-operatively: one chaser and one cutter that cuts across that pursuit arc, and perhaps as many as three or four or more.

If we interject for a moment to consider some of the descriptions of the vocalisations made by tigers, they were said to issue a double “yip” call whilst hunting. In some accounts this is described as communication between hunting tigers - such as in the example above. In other accounts it is said this is between a parent and a young animal as it teaches the young to hunt. So in this hunting scenario we still have communication between at least two individuals - either co-operative hunters, or parent and young.

All of the above suggests that Thylacines co-operated in small numbers, at least while hunting.

If we now take a moment to consider the Thylacine’s life history - tigers probably lived about 8 years or so in the wild. A tiger has four nipples and could theoretically produce and raise four young at once. I think typically though, when mother Thylacines were killed with pouch young, there were smaller numbers of young present - say typically two or three.

It is easy to imagine that as the young tigers develop they would leave the pouch and explore their newfound independence for a while - and I mean minutes - then retreat back into the safety of their mother’s pouch soon after. This kind of behaviour is typical of marsupials and easily seen with, for example, kangaroos.

Over time - some months - the young would become more and more independent, gradually learning hunting skills. Perhaps whilst really small, they might be left in a den while the adult or adults hunt, but soon enough they would join in as described in those stories of adults yipping at young during hunts.

Eventually however, as is the way with just about everything else, the young would leave the parents. In some species, siblings band together for a while in small groups whilst in other species, siblings part ways and travel independently until they can find a mate. I am not sure that I have read any descriptions on how sibling Thylacines behave when becoming fully independent of their parents. It is quite reasonable to assume though, I think, that at some point these tigers become solitary individuals - searching out their own territories, and then mates, which is when they would pair up and begin the family cycle again.

Something else to consider with this scenario of solitary tigers is that we don’t really know how large a tiger’s home range might have been. Estimates vary widely from just a few square kilometres to some tens of square kilometers. If the basic social unit was the family - capped out at perhaps two parents, a couple independent young, and perhaps some new pouch young, but those adults and semi-independent young disperse themselves throughout the territory - perhaps re-uniting each dawn before resting communally, then if a single tiger were caught in this situation, there might be nothing at all to indicate to a trapper that there were other tigers nearby.

What I am saying is that when people caught solitary tigers, it is entirely feasible that there were other tigers in a family relationship with that one, but they were miles away.

Having said that, there are also other stories of trappers or hunters securing one tiger and then remarking that before long its mate or young would come through that way too and they could secure the whole family.

All of the above is based on my impression from a wide range of readings. I don’t have any specific references to hand, but my basic impression is the Thylacine generally lived in small family groups numbering anywhere from solitary animals entering adulthood, to a full family party of about 6 or so animals as just described: adults, independent young, pouch young.

Others answering the question have made a point about the species’ listing status as extinct, so I will add a short comment here also: it is true the species is listed as extinct. Whilst there are countless claims of sightings, no evidence has been accepted as credible enough to reverse that extinct listing. This said, some of the evidence does merit consideration, in spite of official listing status.

Some time ago I drafted an answer to the question of whether the tiger might still persist and you can read about whether the Tasmanian tiger still exists, here on Quora.

Since that time, however, I have gained newer insights into this question. All I will say at this stage is that for me, based on my own research, the picture is shaping up that the Tasmanian Tiger persisted well beyond 1936 and almost certainly into the 1980s and 1990s. (This statement today is based on more than just the evidence considered in the question I linked above.)

As I wrote earlier - if the tiger can persist from 1936 to, say, 1990 (some 54 years) without our being able to “prove” it (and yes, that’s a big “if” - and a vast majority believe it hasn’t survived), then it’s conceivable it could persist from 1990 to today (some 29 additional years) without our being able to prove it.

All that said, in counter-argument, I recently came across a paper investigating Lazarus mammal species - those mammals believed extinct, then rediscovered. It looks as 187 mammal species that had been identified as extinct (or missing). Of these, 67 species were rediscovered. The author notes that of all these 187 species, the one with the greatest search effort (25 searches, as at 2009) was the Thylacine. The article then states “None of the missing species subject to more than 11 rediscovery attempts have been found”.

These stats do not bode well for those believing the Tasmanian Tiger persists!

How, then, can I write that I feel now - even more than a year ago - that it seems so likely the Tasmanian Tiger survived until at least the 1980s? In my mind it depends on what was considered acceptable evidence of persistence in that study. With many Lazarus species we finally lay hands on a definitive body, or camera trap video footage, or similar. The lack of such evidence with the Thylacine is not necessarily evidence of a lack of Thylacines and so, for example, you have David Fleay (world-renown naturalist and champion of conservation in Australia) reporting Tasmanian Tiger tracks stretching for 100 metres in south-west Tasmania in 1945. You have Nick Mooney, Tasmanian Parks and Wildlife Officer writing in 1984 that he concludes Tasmanian Tigers were present in the state’s north-west until at least 1982 (based not only on another Park’s Officer’s sighting - Hans Naarding - but other sighting accounts he took into consideration as he headed up a two year search).

Personally, it’s this juxtaposition between credible people concluding the species is there - even publishing such conclusions as late as 1984, just two years before the species gained its “extinct” status - and the truth that we simply don’t actually have a body or clear camera trap footage, that is so frustrating when considering the question of whether the Tasmanian Tiger persists.

In any case, I hope the above is helpful in considering whether and how Tasmanian Tigers might have lived and moved around in groups - in my opinion, they most likely did, in family units, and most likely also had a solitary stage of life.

You can find out more about Tasmanian tigers - including the examination of the evidence for many sighting claims - at my website Where Light Meets Dark or follow along on Facebook Where Light Meets Dark.