By Mick McCarthy & Hugh Possingham (This article was first published in the November 2012 issue of Decision Point, The Monthly Magazine of the Environmental Decisions Group, and is a modified version of a discussion that appeared recently on the website The Conversation)
At current levels of funding, it is not possible to save all threatened species in Australia from extinction. You might not like that (we definitely don’t) but it is a fact of life. Indeed, to secure all species, the increase in funding might need to be tenfold (see for example McCarthy et al., 2008). Consequently, trade-offs are required. For example, managers could concentrate efforts on the most threatened species, and this is a common approach in many countries. But the price we will pay is that more species will slip onto the threatened species list, and few if any species will be removed from that list.
Alternatively, managers could let the most threatened species go extinct, and concentrate on recovering less-threatened species or focus on stopping other species becoming threatened. Of course, many people will say it’s unacceptable to let the most threatened species go extinct. However, with the resources currently available, it is not possible to do both—that is save the most threatened and stop more species becoming endangered.
The technical aspects of this trade-off are relatively straight-forward. For example, recent research has estimated the effectiveness of different management actions to save species in the Kimberley (see Decision Point #47, p7). The Kimberley is a region containing Australia’s only intact mammal fauna and it seems we have a fair chance of saving it if we as a nation are prepared to spend $40 million per annum (see Box 2 and Decision Point #65, p3).
Weighing up decline against extinction
So the question is: How should the decline of one species be weighed against the extinction of another? Or, a variant on this, how happy would we be if we could keep a species forever in zoos, in contrast to that species having a small chance of persisting in the wild? If preventing the extinction of species is emphasised to the exclusion of preventing declines or promoting recovery, then we are implicitly committed to an increasing number of threatened species.
The best way to allocate effort among species depends a lot on what is valued. It depends on how we value declines versus functional extinction (when a species persists but is well below its normal abundance) and extinction. It’s also about how we value the extinction of one species versus another.
The realm of values is not really a technical issue but a social one: the public largely funds the conservation of species and benefits from their persistence, so it should be for the public to decide what it values. Therefore, the public has a critical role in determining how limited conservation resources are spent.
Unfortunately, nationally and internationally, there has been little public discussion about values in species conservation. Such a discussion is critical, but it needs to be informed to avoid surprises. Without an informed discussion, we might find that only the cutest species are given the highest priority, while some species that are vitally important for ecosystem function could be neglected if they are less charismatic. Fungi, bats and invertebrates come to mind as examples of potentially neglected groups of species that are nevertheless important (often critically important) to the ecosystems on which humans rely.
A simple way of getting a numerical ‘value’ for a species is to google its name and see how many hits you get—arguably this is how much society is interested in that species. But this tells you nothing about its role in an ecosystem nor how important it might be from an evolutionary perspective.
Box 1 Species are not equal
We care about different species to different degrees, and a good example of this is the composition of our threatened species lists.
Approximately two-thirds of species in the world are thought to be insects, while vertebrates make up a tiny fraction (probably less than 1%). If insects and vertebrates had the same extinction risk there should be about 100 times as many threatened insects as vertebrates, but insects are relatively rare in threatened species lists.
Given the paucity of insects in threatened species lists, one might think that they are somehow extremely robust to extinction. Of course, that discrepancy is simply a function of the attention they have received. Species are only listed when there is sufficient information to assess them. Insects and other invertebrates, while loved by some, get much less attention than their abundance, biomass and functional roles deserve.
Triage is honest decision making
The idea of determining which species to save is referred to as conservation triage and it’s all about allocating priorities. The concept of triage arose in the medical arena and it was used during World War I to determine the level of medical effort for different casualties. The aim was to save the most lives with the limited medical resources available. Casualties who would be likely to live or die regardless of the level of urgent medical attention were given less emphasis. Priority was given to those individuals whose outcomes would be greatly improved by immediate medical assistance.
Conservation triage is analogous to medical triage, but it also reflects the fact that not all species are equally valued. For example, efforts to prevent extinction of Anopheles mosquitoes that transmit the malaria parasite would receive little support regardless of how effective those efforts might be.
Further, there are degrees of persistence to consider; species close to extinction might be already functionally extinct, and not playing an important role in the ecosystem. Alternatively, the persistence of the last few individuals of a species is often valued very highly, even inspiring books, radio and television series (consider the program ‘Last Chance to See’). This is to be expected, the idea of losing an animal or plant forever stirs up strong emotion and enormous passion in people.
Species triage essentially boils down to answering a few basic questions:
- How much is the rate of extinction, decline and recovery of different species influenced by the resources that are spent?
- What is the budget available to allocate among species?
- Are there any opportunities available to improve conservation of multiple species or increase the available funding?
- How does the public value different species, and how does the public weigh extinctions of species against further decline and recovery?
This last question essentially determines the management objective—;what the public wants to achieve with the available budget. Then it is a matter of determining which species are funded and the level of funding that optimises this management objective.
This same discussion about species triage can apply to conserving other levels of biological organisation (e.g., genetic diversity, or ecosystem diversity), and also to making trade-offs across these levels. For example, we might ask how best to distribute funding between breeding orange-bellied parrots in captivity versus restoring saltmarsh vegetation in their wintering range. The latter strategy would influence a community of species, but might have less influence on orange-bellied parrots than the former.
Or, we could simply spend more
Of course, to alleviate some difficulties of trading off among species we can simply spend more on species conservation. For example, approximately $3 million is spent annually on conserving threatened Australian birds. This is less than 1% of the weekly defence budget for Australia. Our research suggests that tripling the resources allocated to Australia’s threatened bird species could reduce the number of extinctions over the next 80 years to almost zero, and reduce the number of threatened species by about 15%.
To make this trade-off of costs even more explicit, consider the following. If Australia didn’t fly one of its FA18 fighter bombers for six months per year then we would save enough money to prevent the extinction of all of Australia’s bird species over the next 80 years. We would also have a good chance of recovering 15% of them well enough to remove them from the threatened species list.
Box 2 Honest decision making in an age of extinction
Medical triage is practiced everywhere. It’s not easy or nice, but it’s accepted as a reality of life. Conservation triage, on the other hand, is still seen by some as being immoral and repugnant. But the reality is it’s simply a form of open, honest decision making in which our limited resources are best applied. Anyone expressing outrage at the notion of conservation triage should be obliged to defend what happens without it. Here are some background papers and stories in Decision Point that are worth considering on the topic.
“Anyone expressing outrage at the notion of conservation triage should be obliged to defend what happens without it.”
Around 770 bird species occur in Australia of which around 260 are of conservation concern. Our analysis indicates that an annual budget of $10 million (that’s an average of $37,000 per species of conservation concern) can be expected to reduce the number of threatened species in 80 years time by approximately 15% while limiting the number of extinct species to one. It should be noted that this level of spending is approximately three times what is being spent at the moment.
Prioritising our resources solely on the basis of how close a species is to extinction is poor decision making. It doesn’t take into account your chances of success or the value of alternative actions.
Bottrill MC, LN Joseph, J Carwardine, M Bode, C Cook, ET Game, H Grantham, S Kark, S Linke, E McDonald-Madden, RL Pressey, S Walker, KA Wilson & HP Possingham (2008). Is conservation triage just smart decision making? Trends in Ecology & Evolution 1007:1-6.
The wildlife of the Kimberley is likely to be secured with an initial and immediate investment of $95 million, followed by an ongoing investment of $40 million per annum. The approach we’ve used should help ground conservation investment in the region in a defensible and rigorous framework.