"You don’t have to look, you don’t have to see, you can feel it in your olfactory," sang Loudon Wainwright in a chirpy song about skunk roadkill back in the 1970s.
Likewise, it could be argued that if, as claimed, 5000 eastern grey kangaroos have died of starvation "in one season" at a Federal department of defence training site in Canberra, our noses would know about it. Do the maths. Even if 5000 kangaroos had died in one year, that’s roughly 14 animals a day, building to 98 carcasses a week. There would be, as one kangaroo ecologist dryly observed, "a murder of crows" descending on the site. If we interpret "one season" as three months, the carcass count would be over 1600 a month – which would amount to a serious health hazard for any troops using the training site as well as a unique waste disposal problem. Let’s be blunt here, as well as a murder of crows, the decaying corpses would also attract a buzz of blowflies and a heave of maggots.
Can this estimate be accurate? Or does it simply reveal the usual flaw in using walked ground surveys, or line transects, to estimate kangaroo numbers? This accuracy of this method, and the correction factors required, have been debated since the mid-1980s. These issues were the subject of a paper published in the "Australian Zoologist" almost a decade ago, which argues a case for aerial surveys to gain a better estimate of kangaroo numbers.
And are kangaroos starving at the site? If such large numbers are dying over such a short period, then are we in fact looking at a fatal virus – similar to outbreaks recently reported in northern NSW - which attacks the brain and eyes of kangaroos. Or a macropod alphaherpes virus – similar to that now attacking the immune system of koalas – which was identified in nasal swabs taken from eastern grey kangaroos that died in captivity in Queensland. Has someone done the necessary pathology?
Research in universities across Australia is revealing that macropod biology – that's the biology of more than 50 species of creatures that are usually lumped, by the unobservant, into the generic category of "kangaroo" - is far more complex than previously thought. Recent developments include the revelation that climate change is affecting the breeding patterns of red kangaroos. Heat stress is killing young animals, because they need to work harder – an increased rate of shallow panting and bigger breaths – to cool their bodies. The late Alan Newsome, a senior CSIRO researcher, also did pioneering research that found high temperatures reduced the fertility of male red kangaroos. Has anyone looked at the impact of temperature extremes on mortality rates in eastern greys? Is there a link between drought and increased gut parasite burdens?
Wildlife ecology should not be the domain of popular myth, casual speculation or media manipulation. It is a serious science, requiring mathematically based field work, an understanding of environmental complexities and a formidable intellect. At its best, it’s an enthralling, exhilarating science that’s right up there with the best of astronomy and quantum physics. It’s not about patting critters and taking a stroll through the bush.
As a nation, our politicians are mostly woefully uninformed about our biodiversity, and as a recent Australian Audit office report pointed out, our policy makers often are not fully across the complexities of environmental issues. Does anyone remember that episode of "The West Wing" (it's in the second series) where the White House deputy chief of staff (Josh Lyman) and the communications director (the usually erudite Toby Ziegler) are describing one of America's 12 subspecies of lynx as "a kind of possum’" when briefing the president on an emerging environmental issue? There's also an episode where Josh (a character with a formidable knowledge of political systems) is struggling to establish the difference between a panda and a koala.
Given Australia's vulnerability to climate change, we can't afford this kind of muddle-headed confusion among our environmental policy makers.