You are here
Home > Environment > Kangaroo Archive > Hushed up in 2006: Flawed science, wishful counting as kangas die for pet food

Hushed up in 2006: Flawed science, wishful counting as kangas die for pet food

by Maria Taylor

In 2006, Glenys Oogjes, Executive Director of Animals Australia, publicised the alarming findings of that year’s Commonwealth State of the Environment report. Biodiversity in general was taking a hammering from human land clearing and development. But equally revealing was what she learned about the Australian kangaroo meat and skin industry.

The 2006 State of the Environment report revealed “government decisions relating to wildlife are being made devoid of any substantive data and are having a dire impact on the welfare and numbers of Australian wildlife”, she wrote.

Soon thereafter, Oogjes told the Canberra Times (and since confirmed to the Bulletin), the environment report was altered after she contacted senior officials in the Howard government to discuss the ethical and environmental implications of this assessment.

“We believe the report was changed after pressure from the minister and possibly interests within the commercial kangaroo industry. This is morally wrong. It is meant to be an accurate, independent national report,” she told the Canberra Times.

The original version said “There are insufficient data available on actual kangaroo populations and population characteristics to demonstrate that harvesting does not have a detrimental impact either on the harvested species or their ecosystems”. In particular there was not enough information on population trends, structure or distribution to show a sustainable industry. The final report was changed to read: “Commercial kangaroo harvesting in Australia has been sustainable for more than 25 years….. Current management plans incorporate provisions appropriate to the current drought. Kangaroos have the ability to adjust their reproductive cycle very rapidly to changing environmental effects.”

Drastic population drop mid 2000s, harvest continues unaltered

The original analysis by departmental staff linked the reader to Commonwealth population estimates starting from 1991, which did little to show this was a sustainable ‘harvest’. Instead the Commonwealth numbers (taken from state surveys), indicated an alarming population drop of almost 50 percent for kangaroo species in just one year, between 2002 and 2003:  from 43,845,532 to 28,214,521 animals nationally.

The biggest shown drop was in NSW during these gathering drought years. Queensland also had a major decline. So what were the “provisions appropriate to the current drought”?

According to the 2006 figures, quotas and ‘harvest’ sanctioned by the Commonwealth didn’t budge. Almost four million kangaroos (3,905,277) were shot in 2002. In 2003, despite the 50% population crash over one year, 3,474,483 were still killed nationally. The deleted 2006 analysis noted that harvesting numbers had increased by nearly a million since 1991 and by 2006 were at their highest level ever. Quotas offered the industry have not decreased since.

To put this in context:  in 2001, almost 58 million kangaroos were estimated nationally. Nine years later in 2010 the figure was a little over 25 million, having dropped further from the 28 million counted in 2003. There has been no population recovery with better conditions since. Instead, new shooting areas continue to be opened up in NSW and Queensland (including this south-east region since 2004), keeping the quotas and harvest figures up.

Declining populations throughout NSW

Population monitoring data and myths about kangaroos, including about population ‘explosions’ have been examined by consulting ecologist Ray Mjadwesch, who independently picked up on the same problems as the 2006 analysis.

Based in Bathurst, Mjadwesch started looking at the NSW picture after very publicly questioning the Bathurst city council about the shooting of the resident kangaroo population on Mt Panorama to facilitate a car race in 2009. “There were hardly any kangaroos left in the Bathurst basin,” he says.

Mjadwesch spent the next two years delving into the statistics, population trends and published science of kangaroos. His findings are sobering and have led him to file state and federal threatened species nominations for the four harvested macropod species in NSW: Red and Eastern Grey Kangaroos, Wallaroos/Euros and Western Greys.

The nominations trigger a scientific review of the evidence behind current harvest policies. Mjadwesch hopes this may stem further decline and possible collapse of populations. It has happened before in Australia from koalas to fisheries with ‘commercial harvesting’. His analysis of massive datasets from government agencies found declining population trend lines in every NSW kangaroo management zone.

“It’s a mess,” he says flatly. “Everyone has accepted the state department data as valid and not really looked at it on a zone by zone basis.”

Nor have many questioned the counting methods and population ‘explosion’ assumptions.

How they count

Kangaroo numbers are sampled out of airplanes, then multiplied by a theoretical ‘correction factor’ (based on vegetation type).  A desktop study defines ‘high’, ‘medium’ and ‘low’ kangaroo density areas. On this basis, estimates of kangaroos are then calculated across the whole potential range of the species.

“They often apply their density calculation to landscapes which are completely devoid of kangaroos. Often kangaroos only persist in isolated pockets in farming or grazing landscapes, a tiny fraction of their potential range,” notes Mjadwesch.

“For example kangaroo researchers allocated high densities to the Bathurst basin, an area of 450 square kilometres where there are nearly no kangaroos. This has inflated figures in the Central Tablelands [a new harvest zone] by tens of thousands of animals.” Across NSW this method could be inflating animal counts by the hundreds of thousands, aided by generous estimates from conservation zones.

His trend analyses show counts sometimes fluctuate wildly from year to year with 100 percent and even 300 percent increases suddenly popping up. Biologically that is impossible for a kangaroo population (even pigs with litters of 10 piglets can only attain a growth rate of 86 percent and goats, which frequently bear twins,  can only increase at 50% per annum).

Single births, high infant mortality

He says “the population growth rate for kangaroos during good conditions is likely to run at between 3-8 percent. Kangaroos can have a single joey per annum and 75 percent of joeys don’t make it under ‘normal’ conditions.  A study in the ACT found 50 percent joey mortality from foxes alone.” Drought makes this worse and adult mortality can rise to 25 percent a year.

“Simply put, kangaroo populations cannot ‘explode’ or naturally increase to ‘plague proportions’–– this is a biological impossibility; however they can crash, and that is what we are seeing now. During the last drought, when populations were already declining, shooting devastated kangaroos in western NSW.

Nevertheless, the NSW kangaroo management unit of the Parks and Wildlife Service (which Mjadwesch notes is tied to harvest tags for funding) still offers more than 1.5  million kangaroos annually to the industry, which today manages to shoot  a fraction of that number after a highpoint in 2002. The 2012 quota is 1,518,628 and the 2011 take/harvest was 289,659, indicating there are less animals to be found.

Classic pattern: they ‘harvest’ smaller, younger animals

Mjadwesch says what happens is “they shoot longer hours; they travel further; they shoot smaller animals; they open new harvest zones [which makes the raw figures look stable]. That’s why the Northern Tablelands, Hunter, Central Tablelands and South-East kangaroo harvest zones have been brought on line.

“You can shoot a lot of kangaroos for a long time, but soon enough they are not there to shoot. You move on to the next property, and maybe come back to mop up survivors next year, however this cycle eventually creates a landscape where kangaroos are few and far between.”

The detailed evidence gathered by Ray Mjadwesch, Kangaroos at risk, can be accessed at www.kangaroosatrisk.net

 

Similar Articles

Leave a Reply

Top