Hop into roo before it's too late
A call for Australians to eat kangaroos to combat climate change might be a case of tuck in now before it's too late, research by an Australian biologist suggests.
Writing in the December edition of Physiological and Biochemical Zoology, Dr Euan Ritchie, of James Cook University in Queensland, says population numbers of the iconic Australian marsupial are at threat from climate change.
Ritchie, from the School of Marine and Tropical Biology, says a rise in average temperatures in northern Australia of just 2°C could reduce suitable habitat for kangaroo populations by as much as 50%.
His findings follow a recent call by economist, Professor Ross Garnaut, of the Australian National University, that Australians help fight climate change by swapping their beef-eating habits for a taste of Skippy.
Ritchie, who admits to being a committed roo eater, says his findings should not deter people from kangaroo steaks and may even help the animal survive.
"The species [of kangaroo] currently being harvested are very well monitored," he says.
"So it means we will pick up differences [in range and population] very quickly and will be in a position to respond to that."
According to the study, the kangaroo species under greatest threat is the antilopine wallaroo.
Ritchie says it is more vulnerable because it has a very defined range across the tropical savannas of far northern Australia from Cape York in Queensland across to the Kimberleys of Western Australia.
Using climate change computer modelling, Ritchie and co-author Elizabeth Bolitho, also of James Cook University, found the 2°C temperature increase, predicted by 2030, would shrink the antilopine's range by 89%.
A 6°C increase, the upper end of temperature increase predictions to 2070, may lead to their extinction if they are unable to adapt to the arid environment which results, Ritchie says.
He says the main threat of climate change is not on the kangaroo itself, but on the habitat that sustains its populations.
Among the impacts that will affect their geographic range are increased prevalence of fires and changes to vegetation and the availability of water.
He says a 0.4°C increase would reduce the distribution of all species of kangaroos and wallaroos by 9%.
An increase of 2°C saw the geographic range of the kangaroos reduced by as much as 50%.
Weathering the changes
However the news is not all bad.
By contrast to the antilopine, Ritchie says the eastern gray kangaroo is in a strong position to weather climate changes because of its predominance in the cooler eastern seaboard of Australia.
And he says the red kangaroo and common wallaroo are better adapted to sustain hotter climates.
Professor Lesley Hughes, of the Climate Change Ecology Group at Macquarie University in Sydney, backs Ritchie's findings.
"Virtually every time we do bioclimatic modelling you get this result [of species under threat]," she says.
However she says few studies "go up to 6°C" because "the more you extrapolate into the future the more doubt you have".
Hughes adds however that a 6°C rise in temperature would "wipe out" most native Australian species.