What went wrong with the Eastern Quoll?

Eastern Quoll

The diaries and newspaper reports left for us by the Australian's in the 19th century depict a land where the quoll was in great abundance. Stories of quolls in peoples kitchens, chook yards, the local church, and everywhere in between were a regular theme. Advertisements offering eastern quoll skin rugs and waist coasts were even found in city newspapers, and up until the 1890s it seemed that the quoll wasn't going anywhere.

And then it disappeared.

By 1963 the last eastern quoll ever seen on mainland Australia would be found dead on the road.

So what went wrong, and what continues to go wrong, and how can we stop the eastern quoll going the same way as the Tasmanian Tiger?

It is likely that a population of foxes released just west of Melbourne in the 1860s had established themselves and dispersed through much of Victoria by 1880. By 1888, foxes were crossing the NSW border and by 1903 foxes had colonised most of NSW and were moving towards Queensland. By 1911 foxes were being reported north of Brisbane, and from then on, foxes have been a part of the landscape of eastern Australia.

At the same time newspaper reports were beginning to appear, describing the disappearance of the eastern quoll.

While the fox has always been suspected as causing the decline of the quoll, newspapers were also describing a mysterious epidemic sweeping across Australia, killing thousands of marsupials; including the quoll. Some thought perhaps they weren't being seen much because the newlyintroduced rabbit had become their primary food source, and they had followed their new preferred meal away from the settled districts. Some blamed rabbit fur as being too dense for quolls to digest, resulting in their untimely death. In 1871 an article in The Colonist discusses eastern quolls as being able to exterminate rabbit population if in sufficient densities. It also notes that quoll numbers had been greatly reduced by poisoning and shooting over the previous 50 years; allowing a chink in the armour of the Australian landscape, and allowing rabbits to establish themselves free of a potential predator. The article then goes on to discuss the pros and cons of introducing foxes to Tasmania to control rabbits, however then wisely suggests that this "cure may be worse than the disease". This is probably the first newspaper reference in Australia lamenting the release of the fox onto the mainland.

Whatever the truth is; either the fox, poisoning and shooting, an epidemic, or perhaps a combination of these factors, resuted in the eastern quoll becoming exceedingly rare in most parts of mainland Australia from about 1900 onward.

Populations seemed to hang on however, giving Australian's another 50 years of time to save this species from disappearing from the mainland altogether.

The sad thing is that nobody seems to have done a thing to save them.

Newspaper reports become less numerous as the decades pass. By 1948, when an eastern quoll turned up in Kew, near Melbourne, it seems that most people in Victoria haven't seen a quoll for 30 years. Quolls were still being reported and collected around the suburbs of Sydney, which suggests that perhaps the eastern quolls final mainland strongholds were those areas of bushland protected from foxes by the less penetrable city fringes, may have slowed the now ubiquitous urban fox population. It may have also been a barrier to the poisoning of quolls, which would have regularly occurred in more rural areas, or acted as a barrier to whatever epidemic may have struck the quoll at the turn of the century.

In a little more than 60 years from its initial population plunge, the eastern quoll would be extinct across its entire former mainland range.

Though seemingly secure for another 50 years on the island State of Tasmania, the past decade has seen the quoll population decimated by up to 50%, and local extinctions across its Tasmanian range is now in full swing.

Why?

In 1996 a Tasmanian devil was captured on a field expedition that had grotesque tumours growing over much of its face. In the following decade the numbers of Tasmanian devils plummeted. Extinction of the species in the wild is now a real threat. At around the same time reports of foxes being introduced into Tasmania surfaced, and it was feared that, following the decline in numbers of the devil, the fox would be able to fill the niche of the devil, and colonise the State. Wildlife managers had no other option but to lay 1080 poison baits en masse in the hope that the small population of foxes would be exterminated.

It was thought that with the commencement of baiting for foxes, and the potential for wild dogs to also be destroyed via uptake of the baits, combined with the demise of the devils, that the eastern quoll would fare well, having a greater share of resources available when scavenging through the bush.

What has now become clear is that Tasmanian devils were suppressing feral cat numbers at levels that allowed eastern quolls to persist in the environment.

This 'trophic cascade' of events; whereby the damage to an ecosystems top order predator impacts on other species within the environment, now threatens the survival of the eastern quoll in Tasmania. If devil numbers do not recover, and perhaps even if they do, then the decimation of the eastern quoll and its eventual extinction may mirror the mainland experience.

What this demonstrates is that the current environment of mainland environment is probably even more easily damaged than the island State of Tasmania. Mainland Australia lost its population of devils likely as a result of aboriginal hunting over the last thousand years. With this extinction, a strong line of defense from invading cats and foxes was gone.

The Tasmanian experience demonstrates that if NSW and Victoria are ever to reintroduce the eastern quoll, at least on a landscape scale, we must first reintroduce the devil - in a hope that a healthy devil population would suppress cat and perhaps fox numbers, allowing the eastern quoll to have a chance to survive in the wild.