Free The Best Australian Science Writing 2015 by Heidi Norman

preventing herbivores such as wombats and wallabies from eating out the habitat faster than it can regenerate.
    On this basis alone – its unique role in its environment – the pipistrelle might have had trouble getting aboard the ark. Bats have been around since the time of the dinosaurs, at least65 million years. Australia has about 75 types of native bat and microbat. Losing the Christmas Island pipistrelle was not going to cripple the local ecosystem.
    Not so the endangered southern cassowary. Despite bad press about its antisocial behaviour (the imposing flightless bird has been known to attack and, on at least one occasion, kill humans), it is a vital seed distributor for 238 plants and trees in its north Queensland rainforest home. It is also the only representative of its subspecies on the continent. While habitat loss, cyclones, cars and dogs have reduced its numbers to less than 1000 in the wild – largely concentrated around Mission Beach, Cooktown and Cape York – a medley of local, state and national governments are working with community and Indigenous groups to turn things around for the giant bird.
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    All this being said, the greatest contributors to the health of an ecosystem still frequently miss out on conservation attention. A federal government committee told a senate inquiry in 2014 that mammals, birds and flowering plants were represented in greater numbers in conservation efforts than animals that literally have never grown a backbone. Non-flowering plants, which play a vital role in ecosystems and biodiversity, are simply overlooked.
    The prehistoric-looking Lord Howe Island stick insect is an unusual invertebrate, in that it is listed nationally and internationally as critically endangered. It also has a dedicated captive breeding program. Not all threatened insects are so lucky. ‘Invertebrate animals are 95 per cent of all animal biodiversity but very few invertebrate are listed as threatened species, even though it is likely that many species would qualify for listing if nominated,’ the threatened-species committee told the inquiry.
    Hugh Possingham believes that rather than assessing bats,frogs and Tasmanian devils according to the odds of them vanishing from the planet, governments should manage biodiversity by weighing up the cost and chances of success against the unique nature, or taxonomic distinctiveness, of the animal. Echidnas and platypus score highly on this taxonomic scale, while a medium-sized wallaby would get a low score given the variety of members in its family tree.
    It sounds drastic. But for Possingham, this is how M*A*S*H medics make their life-and-death decisions. ‘Biodiversity is being lost at roughly a hundred to a thousand times the natural rate,’ he says, almost in exasperation. ‘If we are losing species at up to a thousand times the natural extinction rate, then we are effectively in a war zone.’
    Opponents say it is not that simple, and that triage amounts to assisted, unnatural selection. The Australasian Bat Society argues that no one has the right to play God. The independent, non-profit Australian Wildlife Conservancy maintains that if funds are invested correctly, we should be able to save everything. Threatened-species scientists Deborah Ashworth and Todd Soderquist argue that applying triage to animals and plants risks placing the most feasible and affordable projects at the top of the list, while letting the more complicated, long-term or expensive slide to the bottom. ‘The simplicity of this approach is very seductive,’ they warned in their senate submission.
    But governments are coming around to Possingham’s way of thinking. In 2005, Queensland was the first state to introduce a triage test, called Back on Track. The logic underpinning the plan was to recover the greatest number of threatened species. Similarly, Tasmania has focused on 171 threatened species it says can be saved over 50 years