Kangaroos: an iconic species at risk
12 Feb 2014 | Lee Rhiannon
You can read the NSW nomination to list the large macropods as threatened species at: www.kangaroosatrisk.net
Senator RHIANNON (New South Wales) (20:46): In 2011, the four large kangaroos that can be commercially shot were nominated for listing in New South Wales as threatened species. That nomination, based on the government's own data, reveals a serious trend of decline in kangaroo numbers in just about every kangaroo management zone in New South Wales since kangaroo surveys began some 30 years ago. The published science of kangaroo reproductive biology and population ecology shows that the so-called population explosions described in the data-used to assert recovery from decline-are biologically impossible for this slow-breeding marsupial. Current analysis of the survey methodology and raw data is now suggesting systematic and massive inflation of kangaroo numbers, from which corresponding excessively inflated commercial shooting quotas are extracted-so that larger numbers may be shot from shrinking populations.
Two years after its submission, the NSW Scientific Committee has still not made a decision on the nomination. Meanwhile, the commercial shooting industry continues to empty local landscapes of kangaroos in what has been described as the world's largest commercial slaughter of land based wildlife. Often landowners mop up what the commercial shooters fail to kill. But it seems that the idea that macropods-various kangaroo species-might be in trouble is one that simply does not register.
We need to ask: why does this issue receive so little attention? It seems that notions of kangaroo abundance and unquestioning belief in the myth of population explosions are so firmly entrenched in the Australian psyche that we do not think to question the science behind shooting kangaroos. From 2001 to 2011, collated national population estimates across commercial hunting zones in the four mainland states recorded a 40 per cent drop. We need to ask why this is not an issue of concern. Maybe it is because there were still an estimated 34 million in 2011. But this is down from 57 million in 2001, according to the department's own collated figures. These sorts of numbers still seem to correspond with early settler accounts of 'immense flocks' and 'swarms' of kangaroos across our landscapes. That is certainly the impression many people have.
It all suggests abundance-twin myths of plague and pest promoted by a highly organised and strategic-thinking industry via an unquestioning political framework and repeated by uncritical media and unknowing Australians as common fact. Our unquestioning acceptance of those myths has, from 1975 to 2011, permitted nearly 90 million kangaroos and wallabies to be legally shot for the commercial market alone, with an unrecorded estimated additional 24.3 million joeys bashed over the head-and that is actually allowed under the code of practice-or left to die. The notion of a superabundance of kangaroos, and a complacency about the science behind the shooting of kangaroos, is pivotal to the continuing industrial scale slaughter of this internationally iconic animal.
What does the science say and what does the nomination of four large kangaroos to the NSW Scientific Committee for listing as threatened species tell us? What should be engaging the serious attention of our scientists and regulators? In discussing the scientific issues, I first add the proviso that we are talking about four different species of macropod here. This adjournment speech is not the place to cite every one of the 500 published scientific references informing the nomination to the NSW Scientific Committee. That information can be found by reading the nomination itself. But the science does raise serious questions about state kangaroo surveys-on which the commercial industry depends for government licence to operate. Considering the myths the commercial kangaroo industry is based on, some of this science needs to be put on the record.
Contrary to popular myth, kangaroos are a slow-breeding marsupial with low reproductive rates. It is biologically impossible for a kangaroo to increase its own maximum capacity to reproduce. A kangaroo doe can carry a developing in-pouch joey while nursing another at-foot dependent joey. However, it takes about 18 months for a joey to be fully weaned. Thus a kangaroo can raise only one joey to independence per year. That does not change.
Embryonic diapause, which is maintaining the embryo in a state of dormancy-something kangaroos have become famous for-is rare in eastern grey kangaroos, unknown in western grey kangaroos and confers no major reproductive advantage for the reds and the wallaroos in which it occurs. That fact needs to be reiterated. Kangaroos only raise one joey a year to independence. That is how their biology works. Certainly it is amazing that an embryo can be maintained in a state of dormancy, but often the results of that in terms of kangaroo numbers have been exaggerated.
Generally kangaroos in the wild will not start breeding and successfully raising their young to independence until about three years, with their first joey becoming independent at about four years. By 12 years-if the doe lives that long-few females are still producing offspring. A kangaroo doe, then, is biologically capable of producing in most cases no more than eight independent joeys in her lifetime.
Kangaroo juvenile mortality in the first year of life is similar to many other mammals in that it can be high-around 73 per cent. A scientific paper on population ecology of western grey kangaroos found 73 per cent mortality of that species. The ACT Kangaroo Advisory Committee has found mortality in juvenile eastern greys was 'high' in the ACT-although no quantitative work was undertaken in that case. A further study has found that about 50 per cent of emergent young still dependent on their mothers are taken by foxes. With 'close to parity' sex ratios in populations free from historical male bias shooting, and using averages as discussed, this needs to be considered.
A kangaroo will only effectively replace herself once in her lifetime. With her first successfully weaned joey at around four years, and an end to her breeding at around 12 years, she can produce just eight young in her lifetime. However, with 73 per cent juvenile mortality in 'normal' conditions, just two of those joeys will survive to independence. In this hypothetical world of averages, and assuming the sex ratio parity carries through to the two surviving joeys, the original female doe will only effectively replace herself once in her lifetime. I have gone into that level of detail because how the kill rate of kangaroos in New South Wales is determined needs to be brought back to those biological facts.
So, the female doe will only effectively replace herself once in her lifetime-but only if she lives her full natural breeding span without being shot, tangled in a fence or hit by a car; or succumbs to disease or injury or starvation and heat stress during drought. And only if she successfully breeds every year and her joeys do not suffer higher than normal mortality. I have set this out in detail as we need to recognise that it is time to reassess how decisions are made on commercial killings of Australian macropods.
All things considered, and without going into the science of fecundity and birth rates, age structure and other factors such as adult mortality and historical shooting biases, an average kangaroo population is biologically capable of growing around 10 per cent a year. This is in good years when these animals are relatively free of stress from lack of food and water. Studies have found that during drought up to 100 per cent juvenile mortality can occur, with up to 40 to 60 per cent adult mortality. Flooding rains also cause mass or epidemic mortality events in kangaroos, with a lack of funding ensuring the causes remain only hypothesised, including the possibility of toxoplasmosis-a zoonotic disease ever present in wild kangaroo populations and a recognised health risk to human consumers. As an example, in 1998 some 300,000 counted kangaroos died suddenly over two weeks in a 30,000 square kilometre area in south-western Queensland and north-western New South Wales.
So, kangaroo populations will increase in natural environments at a maximum rate in good years of around 10 per cent per annum, but this can crash by up to 40 to 60 per cent per annum during drought or mass mortality events during big wets. Yet quotas for shooting kangaroos sit at 15 to 20 per cent of the preceding year's survey population estimates. This generally is not changed despite population crashes due to drought, flood or fire during the year the quotas apply. Consequently quotas can represent up to 40 per cent of an estimated population during drought.
With commercial shooting rates far exceeding population growth rates over decades, and with these rates usually maintained during drought when populations are known to crash by up to 60 per cent, there should be little surprise that the nomination to the NSW Scientific Committee expresses alarm at what the survey data is showing. The New South Wales government's own data reveals that kangaroo numbers have fallen by up to 90 per cent in some individual New South Wales harvest zones in the last 10 years alone, following a 30-odd-year decline in all harvest zones across the life of these records.
There is no need to interpret the data. This is the status of various kangaroos in New South Wales today, and this is from the government's own data. As little as two per cent of some kangaroo species remain in some areas, and preliminary examination of NSW survey transect data recently released under FOI is shows some 85 per cent of five-kilometre survey transect segments returned zero counts-that is, no macropod species. If this of itself is not alarming enough, examination of the survey methodology should raise concerns about basic scientific method and validity of the data. Two reports to the New South Wales Department of Environment and Climate Change amplify these concerns. One report-'Kangaroo monitoring: design & analysis of the Northern Tablelands region helicopter survey'-appears to have been removed from the internet. The other report is 'Kangaroo monitoring: Hunter and Central Tablelands commercial harvest zones design and analysis of helicopter survey.' Both contain very important information.'
This work shows that in one case 26 actual, counted kangaroos were multiplied by 1,456 to become a final population of over 37,000 animals in the Armidale region. That occurred in 2007. In the central tablelands, 1,362 actual, counted eastern greys were extrapolated into a population of 535,600. From these inflated figures, the commercial shooting industry is then allowed to shoot a quota of 15 to 17 per cent of those populations. Again, that is why I have set out the detail of how this methodology operates or, I should probably say, 'fails'-because that quota is based on those inflated figures.
This occurs because of a deeply flawed methodology. The number of transects has often doubled from one survey session to the next. Transect widths have been narrowed without a corresponding lowering of detection factors. Transects overfly national parks and other non-shooting areas, with those numbers applied to surrounding empty landscapes. For example, roughly half the transects in the central tablelands shooting zone overfly national parks and other non-shooting kangaroo habitat. Those non-shooting areas are removed from the equation to further inflate extrapolated densities of empty landscapes. Transects that continually show no kangaroos over regional landscapes have been dumped. This has happened for parts of western New South Wales. Finally, correction or detection factors, a number by which actual, counted numbers are multiplied, are continually increased. This can result in the multiplying of actual counts by up to 300 to 500 per cent. So this flawed methodology is how we see biologically impossible jumps in the number of kangaroos-the so-called population explosions.
In the Bourke kangaroo management zone, the latest survey report asserts that from 2011 to 2012, a year bookended by drought in rural New South Wales, kangaroo populations apparently increased by 249 per cent. Yet this nonsense of a population growth rate of 249 per cent in one year has not been challenged. Growth rates of 50 per cent or more are regularly reported by the department's consultants, but that would require true male-female parity, every female successfully raising young to independence and no animals at all dying for 12 months. Growth rates of between 100 and 300 per cent continue to be asserted.
The systemic nature of this absurdity is illustrated in Queensland's 2013 quota submission to the federal government for export approval of Queensland's kangaroo management plan. For the shooting block of Emerald, it shows a fanciful 371 per cent increase in wallaroos per year for two years, from 2010 to 2012. Little wonder, then, that the industry boasts about its environmental credentials-because its 'take', it argues, can be as little as three or four per cent of the kangaroo numbers it is allowed to shoot. But we now know those numbers are regularly a gross overestimation.
The industry is working hard to access kangaroos in new areas by extending commercial shooting zones across Australian states, including the ACT and Victoria. That is where it wants to go. It is worth noting that Victoria actually stopped commercial shooting in 1982 because 85 per cent of the state had less than one kangaroo per square kilometre. It would be a tragedy if kangaroo shooting started again in that state. The industry is working hard to shift the market for kangaroo from cheap pet food to the more profitable meat for human consumption. This continues despite the unambiguous health risks of toxoplasmosis and other zoonotic diseases associated with undercooking this meat, something often recommended by the industry.
There is growing concern about how the Kangaroo Industry Association of Australia shapes government kangaroo policy, with trade, foreign affairs and environment ministers actively going overseas to promote this market. That is work that, clearly, a lot of public money goes into.
The 2011 New South Wales nomination of kangaroos to the New South Wales Scientific Committee raises serious questions about the operation and sustainability of the commercial kangaroo industry. The issues and realities of kangaroo slaughter sit at the edges of public awareness; I do acknowledge that-but it is not surprising, considering the myths that are perpetuated here. So ingrained are these myths of the abundance and pest status of our kangaroos that they are frequently repeated without examination of the facts. It is not considered that the trashing of water points and waterways, the 95 to 98 per cent clearing of grassy woodlands-prime kangaroo habitat-along with heavy predation by foxes and humans, habitat division by roads and fences, and introduced endemic disease have made life pretty hard for the kangaroo, this amazing creature.
These myths are carefully nurtured by the industry via a well-honed communications strategy that has embedded itself into an unquestioning political framework that lobbies overseas politicians, the media, the market and the consumer. Scientific concerns are diminished by industry's advice to government as the work of activists, and evidence of the cruelty to and suffering of regularly mis-shot kangaroos is labelled as 'extreme'. Meanwhile, the industry commissions its own work to produce explicitly industry-biased materials which are then presented as independent research to overseas governments and an unsuspecting Australian public.
The links between the KIAA and governments and their partnered funding of marketing and promotional research reveal a powerful web of interests, a lack of independent oversight or peer-reviewed science, and a closed shop of industry-funded 'scientific expertise'. This decades-long, highly successful strategising and marketing by industry has diverted attention from the compelling concerns raised by the nomination to the New South Wales Scientific Committee that kangaroos are indeed at risk. It is time that federal and state governments actually engaged with this issue independently, scientifically and in good faith. Given the historical antipathy towards our iconic species, histories of other so-called superabundant species suggest this needs to happen urgently. Thank you.