This article relates to the ongoing debate on Australian Rural & Regional News: Open for Debate: Koalas
Vic Jurskis
Forestry Australia says “The many threats contributing to koala decline, include climate change related issues such as increased occurrence and extent of intense bushfires, disease, road kills and loss of habitat due to urbanisation and land clearing. We must address all of these if we are to improve the outlook for Koalas in NSW.”
Fact is, there are many more koalas across a much wider range than there were when Europeans arrived in Australia. They are increasing faster than ever with all the soft young eucalypt shoots after the Black Summer fires. Naturally rare koalas in healthy mature forests have chlamydia but not the disease chlamydiosis. They live solitary lives in home ranges of around 100 hectares with thousands of trees.
Europeans first observed koalas in new forests which had grown up half a century after they arrived in Sydney. In the 1830s, koalas irrupted in dense young forests in the foothills of the Blue Mountains and in the Strzelecki Ranges of South Gippsland. The young forests grew up after Europeans disrupted Aboriginal burning near Sydney and European diseases disrupted it in the Strzeleckis.
Koalas didn’t appear in the grassy valleys sought by pastoralists until 30 years later. There were none in the Bega Valley when Europeans arrived in 1830. They bred in the dense young forests growing up in the foothills, and dispersed into the retained red gums in the valley. The old trees were constantly resprouting soft shoots as their roots deteriorated in the improved pastures. Koalas appeared at Bega in the 1860s and there were plagues of diseased koalas by the 1880s. A skin industry was established in response.
New South Wales’ Chief Scientist told the Environment Minister that Europeans first saw a koala near Campbelltown in 1798. In fact, a convict who’d lived with Aborigines showed an explorer some distinctive koala dung south of the Cumberland Plain and the Nepean River at Pheasants Nest. Further south, in 1802, Barallier’s Aboriginal guide Gory bartered two spears and a tomahawk for two feet – a very high price for hardly a choice cut. Koalas were rare.
Aborigines were employed to look for koalas, and the first was not brought in until 1803. Koalas did not appear on the southern fringe of the Cumberland Plain near Campbelltown until the 1890s. They irrupted in plagues and suffered disease. They were shot for their skins. The more adults that were shot, the more young that survived. They continued to irrupt until the Federation Drought frizzled the soft young eucalypt shoots that they rely upon for nutrition and moisture. Then they crashed.
In 2016, the Chief Scientist said “Koalas were historically distributed throughout the woodlands and forests of NSW but have experienced significant declines in both numbers and distribution. … The first recorded sightings of koalas by Europeans occurred in 1798 … koala populations experienced rapid growth in the decades following European settlement … Urban development in the late 19th century, combined with fire events and agricultural expansion, led to a decline in the geographic range of the koala due to the loss of habitat … Surveys in NSW indicate that since 1949, populations of koalas have disappeared from many areas (Reed, Lunney, & Walker, 1990)”.
In fact, after the plagues in rural areas crashed in the early 20th Century, koalas were declared extinct in NSW, mainland VIC and SA. The map hereunder was produced in 1934 by the founder of Sydney’s Koala Park five miles north of Parramatta. The first agricultural enterprises in Australia had begun on the Cumberland Plain around Parramatta. Eucalyptus tereticornis and E. parramattensis occurred naturally there and are now listed as primary food trees for koalas. But there have never been any wild koalas in the vicinity of Parramatta (Reed, Lunney and Walker 1990).
Koalas continued to live at low densities in mature forests and breed up in young regrowth or in forests declining for want of maintenance by mild fire .
A mail-out survey in 1949 received reports of 109 koala sightings throughout NSW over three decades. In 1975, another mail-out produced many more sightings from many more locations. In a 1976 symposium on The Koala at Taronga Zoo, forty-three experts reached “unanimous agreement that the koala is no longer an endangered species”. The editor of the proceedings stated that there were “large, growing populations” of koalas across their range. In 1986/7 a third mail out again revealed increasing sightings/locations.
But NSW National Parks and Wildlife Service (NPWS) compared the returns of sightings since 1985 against all records of koalas from the 1920s up to 1985 and wrongly declared that koalas had disappeared from hundreds of localities across the state. This was the start of The Great Koala Scam. They organised a Koala Summit at Sydney University in 1988 and commenced a very successful campaign using the koala to halt logging and transfer lands from State Forest to National Park.
This has culminated in the current Great Koala National Park proposal which a new ALP government has promised to implement if elected. The NPWS campaign has gradually been extended to use increasing koalas and their increasing dispersion into private lands, to increasingly regulate or prevent private developments. Disease, dog attacks and collisions with vehicles, alleged causes of declines, are actually symptoms of increasing numbers of koalas in forests, consequent overcrowding and their dispersal into expanding suburbs.
For example, during a decade before the start of the Millennium Drought, koalas within the expanding urban footprint on the Koala Coast increased from much less than 0.4 ha-1 to 0.7 ha-1 despite high levels of disease, dog attacks and roadkill. As the Millennium Drought intensified after 2001, they crashed back down to the maximum long-term sustainable level of about 0.1 ha-1. As they crashed, disease remained at around 52 per cent of hospital admissions whilst vehicle injuries declined from 30 per cent to 10 per cent and wasting increased from 3 per cent to 20 per cent.1
Dense sub-populations crash when they run out of food during droughts. But irruptions continued near Bega and around Sydney, Coffs Harbour and Lismore-Tweed during the Millennium and Black Summer Droughts, including in areas burnt by megafires, because they haven’t yet reached maximum short-term densities. Tweed Shire recently reported 30 vehicle strikes and dog attacks in just three months.
The Chief Scientist’s 2016 “Independent Review into the Decline of Koala Populations in Key Areas of NSW” was based largely on “NSW koala population case studies, July 2016. Document prepared by Martin Predavec”. Predavec was an officer of NPWS / Office of Environment and Heritage (OEH) but this was not acknowledged in the document.
The review wrongly reported on numbers of koalas in the ‘key areas’ as follows:
- Coffs Harbour “stable to slowly declining”
- Pilliga-Gunnedah-Liverpool Plains “a decline of over 80 per cent since the 1990s”
- Campbelltown “a low density population that is persisting”
- South Coast [Bega Valley Shire] “30 – 60 individuals remaining in the north-east corner”
Koalas at Bega, Coffs Harbour and Campbelltown were still increasing and the unsustainably dense sub-population in northwest NSW had obviously crashed in the Millennium Drought, as it had previously during the Federation Drought/Great War Droughts.2
After Black Summer, in September 2021, the Commonwealth Threatened Species Scientific Committee (TSSC) finalised an assessment that QLD, NSW and ACT koalas are an Endangered Species even though it is the same species as in VIC and SA where it is not even officially ‘vulnerable’. There are koalas living on the NSW-VIC border that are Endangered one day and not the next as they move around their home ranges.
My offer to consult with TSSC on the assessment was rejected. Dr. Brad Law of NSW Department of Primary Industries was one of 84 experts consulted. At the time, Law had data showing: that koalas at Gunnedah had once again irrupted to very high densities of 0.6 ha-1; that the so-called Campbelltown koalas extended across the upper Nepean and the Southern Highlands to Canyonleigh; that the koalas near Bega were at just as high densities as the well-known ‘population’ at Bongil Bongil near Coffs Harbour.
Dr. Law had already published data showing that the koalas near Bega were at higher densities than on the north coast generally. As co-editor of Australian Zoologist he was undoubtedly aware of the 2015 paper in that journal by Robert Close, Steven Ward and David Phalen suggesting that the so-called Campbelltown population extends all the way through continuous forest to Victoria.
None of these three scientists who’ve conducted a long-term study on the increasing sub-population of koalas south of Sydney are on the list of experts consulted by the TSSC. Evidence given to NSW Koala Inquiry by Dr. Kellie Leigh indicates that the ‘Campbelltown koalas’ extend through the Blue Mountains to the Hunter Valley. Dr. Leigh was consulted by TSSC.
I have no way of judging whether either the Commonwealth or State TSSCs have been exposed to the incontrovertible scientific evidence that NSW koalas are neither endangered nor vulnerable to extinction. All sub-populations from Victoria to Queensland are currently increasing. The Chair of the Commonwealth TSSC, Dr. Helene Marsh said that she read my peer-reviewed ecological history published in CSIRO’s Wildlife Research. But I was not given the opportunity to present TSSC with more recent information including changes through Black Summer.
The TSSCs apparently preferred expert guesses to scientific data. Forestry Australia certainly hasn’t troubled to look at the data. “Science-based active forest management approaches” would make no difference to the security of the species. They would restore healthy open forests with a much lower, but sustainable, carrying capacity for koalas. This would not only reduce the suffering of koalas currently going thru boom and bust, but also improve the security of truly endangered species reliant upon sunshine, air circulation and diverse ground layers.
A good example is the endangered broad-headed snake whose habitat near Campbelltown and through Morton National Park to the south is being choked out by scrub.
1. Reed, P., Lunney, D., Walker, P. 1990 A 1986–1987 survey of the koala Phascolarctos cinereus (Goldfuss) in New South Wales and an ecological interpretation of its distribution. In Biology of the Koala. Eds. A. K. Lee, K. A. Handasyde, G. D. Sanson. Surrey Beatty, Sydney. pp. 55-74.
2. Jurskis, V. 2017 Ecological history of the koala and implications for management, CSIRO Publishing, Wildlife Research
Many related articles on these issues can be found at Open for Debate: Koalas
Vic Jurskis has written two books published by Connor Court, Firestick Ecology and The Great Koala Scam.
