Vic Jurskis

According to NSW Office of Environment and Heritage, koalas were “conspicuously absent from the explorer Clement Hodgkinson’s account [published in 1845] of the tribes he encountered along the Bellinger River, in which he noted animals they consumed”. There were no records of hunting for skins, or historical photographs, and few oral histories of koalas at Coffs Harbour. A newspaper report from 1950 indicated that a resident in the area from 1896 to 1901 saw koalas, and there was a newspaper report of a koala crossing a road three quarters of a mile from Coffs Harbour in 1939.

In an oral history recording from 1987, an 82 year old woman recalled seeing koalas in town around the late 1920s and early 1930s. A postal survey in 1990 attracted a respondent who saw a koala in Conglomerate State Forest as a young man in 1937, another who saw koalas at Nana Glen as a child around the 1950s and a third who saw koalas in dense scrub or “up telegraph poles” in Coffs Harbour in the 1940s. Apart from the foregoing, OEH found no records of koalas in the region prior to the 1960s.

Koalas apparently irrupted in the immediate vicinity of Coffs Harbour township around 1960 with the commencement of urban sprawl and consequent reduction of grazing and burning. Koalas which had been increasing in dense young regrowth forests created by intensive post-war logging using chainsaws and bulldozers, invaded former grazing paddocks acquired for residential development.

A similar process occurred in southeast Queensland from the 1980s when the Moreton Bay District became the Koala Coast. Now it is happening in new residential areas such as Waterview Heights near Grafton. OEH found many references to koalas at Coffs Harbour after the 1960s and reported that koalas disappeared from some suburbs and localities as urban development progressed.

By 1991, koalas had become abundant in dense regrowth forests and plantations around Coffs Harbour. There were three times as many koalas in heavily logged forests (22% detection rate) compared to unlogged oldgrowth forests (6%). The regional detection rate in listening/spotlighting surveys was 16%. In 1992 NSW’s government declared them a Vulnerable species. In 1995 regrowth forests and plantations near Coffs Harbour were reserved as Bongil Bongil National Park to ‘protect’ koalas.

At that time, koalas were rapidly increasing in both young and old forests suffering decline and constantly turning over soft young shoots as a result of reduced maintenance by mild burning. They were detected at 46% of survey sites in the Upper Clarence and Richmond Valleys. They became the most common arboreal mammal in Urbenville District, occurring throughout forests where they had previously been uncommon.

By the turn of the millennium there were more than 20,000 hectares of severely declining forest in the upper northern rivers area. Koalas and a range of other species including arbivorous insects, fungi and parasitic plants increased as forests declined. So-called Bell Miner Associated Dieback (BMAD) is a facet of this more general problem.

By 2009, OEH reported that the Coffs Harbour region was one of three areas in NSW where mail-out surveys showed that koalas were increasing. Another mail-out survey in 2011 produced another increase in sightings. OEH stated that “While the raw data show an increase in the number of koalas … they do not account for the forgetfulness of people”. So, OEH “downsampled” postal survey data and “adjusted” it for “forgetfulness”.

This turned a sampled increase in koala sightings between 1990 and 2011 into “a small, yet statistically significant, decline in the number of koalas of 4% over 21 years”. OEH concluded that “habitat loss has been relentless since European Settlement and the Koala population had been reduced from its pre-European size by 2000”.

In September 2011, a Senate committee erroneously concluded that koalas were generally declining from numbers of up to 10 million at the time of European arrival. They recommended “that the Threatened Species Scientific Committee provide clearer information to the Environment Minister in all future threatened species listing advices, including species population information, and that the Threatened Species Scientific Committee review its advice to the Minister on the listing of the koala in light of the findings of this inquiry”.

In May 2012, koalas north of the Victorian border were listed as Vulnerable. In July 2012, fifteen koala experts gathered to ‘synthesise’ koala numbers and trends “in the absence of empirical data”. Using the ‘Delphi Process’, named after the legendary oracle, they decided that koala numbers on NSW’s north coast had declined by 50% in three generations. This was the largest alleged decline of any region in NSW.

In 2015, eighteen koala experts including thirteen of the fifteen aforementioned wrote: “Unpublished data indicates that the Lismore population of north-east NSW appears to be benefiting from the planting of eucalypt trees as windbreaks on the region’s orchards (S.P., pers. obs.), and a long-term data set from Coffs Harbour, also on the north coast, showed the population change was best characterised as stable to slowly declining”.

In July 2016 a “Document prepared by Martin Predavec”, an officer of OEH, stated that “the koala population of Coffs Harbour … is best characterised as stable to slowly declining”. In December 2016, NSW Chief Scientist’s “Independent Review into the Decline of Koala Populations in Key Areas of NSW” found that the “Coffs Harbour population can be best characterised as stable to slowly declining”.

Bellbirds have also irrupted across NSW’s north coast in response to irruptions of psyllids in declining trees. Psyllids constitute plentiful, nutritious food for the birds. Now there are not many coastal forests where you can travel any distance without hearing bellbirds. At the same time, there are many places where you can smell koalas as you walk along, as if you were walking past an enclosure in a wildlife park.

Dense scrub-infested forests, megafires and plagues of arbivores are all consequences of lack of ecological maintenance by mild fire. Between 2015 and 2017, aerial surveys by NSW Dept. of Primary Industries identified 44,000 hectares of ‘BMAD’ on the north coast, comprising about 4% of the survey area. This is a huge underestimate of the area of declining forest, representing only areas of dead or near dead canopy. Forestry Corporation has identified that about a third of the forest area has impenetrable understorey. Much more is thickly scrubbed but not yet impenetrable, and other areas of declining forest have thick litter layers or groundstoreys. The majority of the forest is declining in health.

During the same period, Dr. Bradley Law and colleagues from DPI “sampled a broad range of timber harvest intensities and times since harvesting, at both site (~ 300 m radius) and a larger landscape scale (1 km buffer), together with old growth forests for comparison” across the north coast. They found (male) koalas at 64% of sites irrespective of: whether there had been any logging; the intensity of logging; or time since logging. Koalas have increased throughout the declining forests since 1990, occurring at densities of more than 0.03 per hectare. That is more than three times the density of natural populations in healthy mature forests. They are no longer associated with young regrowth.

DPI said that koala densities were five times more than expected based on previous surveys using alternative methods. They were indeed four times higher than those recorded by listening and spotlight surveys 26 years earlier. Koalas were still concentrated in the coastal forests, with occupancy ranging from 75% at 10 metres above sea level to 13% at 1300 m asl.

These data were all available to TSSC when they recommended that northern koalas should be listed as an Endangered Species.

Meanwhile, OEH’s ineffective mail-out survey technique has morphed into “internet-based participatory mapping survey” otherwise known as “geographic citizen science”. In 2018 five universities, four regional councils, OEH and Friends of the Koala, collaborated in a north coast koala study which produced no data from which credible population estimates could be derived.

They reported “that crowdsourced wildlife observations, if sufficient in number and geographic scope, can be used to cross-validate and update wildlife distribution models. Wildlife populations, such as the koala, are dynamic, especially in a study area experiencing significant pressures on the populations from loss of koala habitat, human-induced mortality (e.g., from cars and dogs), and the spread of infectious diseases”.

In plain English – a recent unbalanced, i.e. biased, set of casual observations of a cryptic species was tested against a model based on earlier biased casual observations, and found to be better because there were more observations. This was despite supposed pressures from clearing, cars, dogs and disease. The most important implication is apparently that more observations can be used to update models that are, in any case, of no real use.

I suggested, in The Great Koala Scam, that balanced sampling using an efficient survey technique that actually works in the bush would be a more scientific approach. In the meantime, accumulation of more casual sightings in a shorter time period indicates that koalas are increasing as revealed by previous field surveys.

Obviously, that’s not how the experts see things. They concluded that: “the north coast of NSW has almost every koala conservation and management problem that exists … detailed, on-ground, labour-intensive surveys are not feasible except in a few locations. Geographic citizen science provides a way forward so that government can gain a reliable grasp of the conservation and management issues facing koalas”.

However, a consultant’s report to OEH, obtained under the Government Information (Public Access) Act, states that data obtained from such surveys are biased towards rural and regional centres, and State Forests where there have been field surveys, whilst they underestimate koalas’ occurrence in existing National Parks. So they can be very useful to anyone who might like to use public concern about koalas to support calls for an increase in National Parks at the expense of State Forests.

On 11^th February 2022, Environment Minister Susan Ley announced that koalas north of the Victorian border are officially Endangered. This declaration relied on expert advice to TSSC that north coast populations had declined by 50%. This advice was contradicted by other advice by many of the same experts which was also not based on empirical data.

New information from field surveys on NSW’s north coast was published on 15 February and 10 March 2022: DPI recorded koalas at 97% of survey sites in north coast forests in 2019. After Black Summer they found that koalas were lost where high fire severity dominated, but were returning within a year. Where moderate severity fire dominated, koala density was reduced by about 50% in the first year. In areas dominated by low severity fire, there was no impact on koala numbers. Ten percent of the landscape was burnt by mostly high-severity fire and six percent by moderately severe fire, so there was about 13% loss of koalas in the fires according to DPI.

Given that koalas on the north coast increased by about 29% in two years before the fires (75% occupancy in 2017 to 97% in 2019), there was a net gain of about 15% despite the fires.

Numbers are now increasing faster than ever because of increased recruitment of young koalas in all the soft young growth from the fires.

Koalas are not declining anywhere. Some unsustainably dense sub-populations crashed in the Millennium Drought just as many did in the Federation Drought a century earlier. Koalas are a rare species in healthy mature forests. Where they are in plagues, their numbers must inevitably crash when chronically declining trees succumb to drought, and fires will inevitably explode when dense scrub is ignited by accident, arson or lightning in extreme weather.

Koalas on NSW’s north coast are the same species with the same ecology as koalas in Victoria’s supposedly last natural ‘population’ in the Strzelecki Ranges and the same as koalas introduced to Kangaroo Island. Both natural sub-populations have similar unnaturally high densities of more than 0.03 animals per hectare. The Strzelecki koalas have experienced 20 megafires in 200 years, including the First Australian Megafire around 1820, Black Thursday 1851, Red Tuesday 1898, Black Friday 1939 and Black Saturday 2009. When clearing commenced in the 1870s there were plagues of dingoes feeding on plagues of koalas in the 20 year-old and 50 yo. stands.

Scientific data from historical reports and field surveys show that there are many more koalas over a much wider area than there were when Europeans arrived. They are an irruptive species in no danger of extinction.

References

These data, up to the end of 2020, are fully referenced in my Ecological History of the Koala  CSIRO PUBLISHING | Wildlife Research and THE GREAT KOALA SCAM: green propaganda, junk science, government waste & cruelty to animals — Vic Jurskis (connorcourtpublishing.com.au)

New data published since the inappropriate and unscientific listing of northern koalas as Endangered are available here:
Regulated timber harvesting does not reduce koala density in north-east forests of New South Wales | Scientific Reports (nature.com)
Fire severity and its local extent are key to assessing impacts of Australian mega‐fires on koala (Phascolarctos cinereus) density – Law – 2022 – Global Ecology and Biogeography – Wiley Online Library

Australian Rural & Regional News asked a few further questions of the author, Vic Jurskis who responded as follows:

Vic Jurskis: Dear Editor, Thank you for your interest and willingness to have a discussion. Here are my responses to your questions:

ARR.News: You state that “koalas are not declining anywhere”.
Until there is reliable, empirical data on koala numbers across Australia over a period of time – which appears to be a key problem – this claim is impossible to substantiate, indeed, as impossible to substantiate as a claim that koalas have declined everywhere. Do you agree?

Vic Jurskis: No! There are abundant reliable empirical data showing that koalas were rare and confined to dense forests when Europeans arrived. They irrupted after Aboriginal burning was disrupted and invaded the areas originally occupied by European pastoralists and now increasingly by suburbia. There are also abundant reliable data on consequent cycles of boom and bust. I’ve referenced the data in my publications.

Bureaucracies and NGOs have successfully manufactured, misrepresented or even hidden data to achieve their goal of Lock It Up and Let It Burn ‘conservation’. It’s working fine for the species and the industry but not so good for individual koalas that are suffering. More importantly it’s an entirely preventable environmental and socioeconomic disaster.

ARR.News: What figures are you relying upon to support the 0.03 animals per hectare in the Strzelecki Ranges and Kangaroo Island?

Vic Jurskis: I said nothing about koala densities on Kangaroo Island. I assume they were much higher than 0.03 in blue gum plantations before Black Summer. The maximum density measured in the Strzeleckis is 0.29 koalas per hectare, but “densities are much lower outside these areas of good quality habitat” (Wedrowicz et al. 2017). Koalas irrupting north-east of Bega occur at 10 times the density of those in the rest of the Eden region. A conservative estimate for the Strzeleckis as a whole is one tenth of the maximum or 0.03 per hectare.

ARR.News: What is your proposed “balanced sampling using an efficient survey technique that actually works”?

Vic Jurskis: Balanced means sampling various lands in proportion to their area. An efficient technique that actually works is listening for or recording male bellows in springtime. Forestry staff and volunteers used playback of recorded bellows and listening in a survey which detected koalas throughout the Eden Region in 1997. We identified the high-density sub-population using young regrowth forest in the northeast (Jurskis et al 2001).

ARR.News: What ultimate outcome are you hoping for from your research and criticism? What is it that you want to see happen?

Vic Jurskis: Sustainable fire management to restore a beautiful, healthy, safe, resilient and diverse landscape. Eucalypt forests need mild fire at intervals of 3 to 6 years to achieve this.

References

129-138_human_fire_maintains_a_balance_of_nature.pdf (bushfirecrc.com)
Jurskis, V., Douch, A., McCray, K., Shields, J. 2001 A playback survey of the koala, Phascolarctos cinereus, and a review of its distribution in the Eden region of south-eastern New South Wales. Australian Forestry 64, 226-31. doi:10.1080/00049158.2001.10676193
Wedrowicz, F., Wright, W., Schlagloth, R., Santamaria, F., Cahir, F. 2017 Landscape, koalas and people: A historical account of koala populations and their environment in South Gippsland. Australian Zoologist 38, 518- 36

Vic Jurskis has written two books published by Connor Court, Firestick Ecology and The Great Koala Scam. 

Related article: Koalas: How threatened? Threatened how?