Bans on kangaroo products are a case of emotion trumping science
Since 1984, four species of kangaroo — the Red Kangaroo, Eastern Grey Kangaroo, Western Grey Kangaroo, and Common Wallaroo — have been harvested for their meat and skins across large areas of Australia, under management plans approved by the Australian government. This harvest is opposed by critics who claim that it is unsustainable and puts kangaroos at risk.
The critics may be winning the debate. Their latest victory has been to convince – through a flurry of lobbying and social media campaigning – the state of California to bring back a ban on imports of kangaroo products.
But the evidence suggests that this ban isn’t justified.
The kangaroo harvest is sustainable
In fact, Australia’s kangaroo industry is one of the best-managed wildlife harvests in the world. It stands out for three reasons.
First, it is based on a sound understanding of the ecology of kangaroos, in particular the way their populations fluctuate in Australia’s variable climate. The harvest is regulated on the basis of CSIRO-led research that developed robust models of kangaroo population dynamics, and used them to simulate effects of harvest on long-term abundance. Many studies have since extended this knowledge and measured the impacts of harvesting.
Second, the harvest strategy is appropriate for variable environments and robust to uncertainty. Many harvests of wild populations use fixed quotas, meaning that if the population declines the relative impact of the harvest increases, which can rapidly drive abundance to dangerously low levels.
In contrast, the kangaroo quota is adjusted each year to represent a constant proportion (10-20%) of population size. If abundance falls, so does the harvest quota.
There are other built-in safeguards: refuges such as national parks function as no-take zones; harvest rates are well below quota in areas remote from tracks or processing facilities; regulators are government conservation departments whose overriding objective is to maintain viable populations, rather than support an industry; harvesting ceases if populations drop below a pre-determined threshold; and population estimates are conservative.
Third, population size of the harvested species is monitored. Often, wildlife harvest programs use harvest statistics themselves to indirectly infer changes in population size, but population size of kangaroos is determined directly, using reliable survey methods that are independent of the harvest.
This allows us to test whether the harvested populations are in long-term decline. They are not. The harvested species remain abundant and widespread. While numbers fluctuate, sometimes dramatically, this is mostly due to the impact of drought on survival. Data on population size and quotas for harvested species are publicly accessible.
Kangaroo harvesting and biodiversity conservation
It is certainly true that some kangaroos are at risk. But these are not the commercially harvested species.
Of 58 species of kangaroos and their allies (families Macropodidae and Potoroidae) that were in Australia at European settlement, eight are now extinct and a further 14 are threatened with extinction. The loss of these species is part of a wave of extinction that has seen at least 29 species from Australia’s unique mammal fauna disappear forever.
While this is a dire problem, exploitation did not drive these losses, and the species that are now threatened are not harvested. They are small and medium-sized creatures that have declined because of predation by introduced foxes and cats, and, in some cases, habitat degradation.
The ongoing argument over sustainability of the kangaroo harvest is a misguided and poorly informed distraction from the genuinely urgent task of preventing further extinctions of species like these and helping the survivors to recover.
Worse, if these critics were to succeed in ending kangaroo harvesting, the quality of habitat for threatened species could decline further.
Across much of Australia, the abundance of large kangaroos has increased since European settlement. Probably the most important reason for this is suppression of dingoes, which are formidable kangaroo hunters. Provision of water for livestock and clearing for pasture also helped make habitat more suitable for these large kangaroos.
In many areas, overgrazing by kangaroos is now reducing habitat quality for other species. High abundance of kangaroos reduces vegetation cover, making small native animals more vulnerable to predation by foxes and cats; rare species find it even harder to survive.
Australia faces a biodiversity crisis. More native species are likely to go extinct unless public support for conservation increases and conservation management improves. This should be informed by good science, not emotive campaigns.
We welcome the concern for Australian wildlife expressed by opponents of the commercial kangaroo harvest. However, it is misplaced and misleading. Biodiversity conservation would be better served if that concern were directed to the plight of the many Australian species that really are in trouble.
This article was written with the help of Dr Tony Pople of Biosecurity Queensland.
Christopher Johnson, Professor of Wildlife Conservation and ARC Australian Professorial Fellow, University of Tasmania; John Woinarski, Professor (conservation biology), Charles Darwin University, and Rosie Cooney, Visiting Fellow, Institute of Environmental Studies, UNSW Australia