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The importance of value in species prioritisation – a holistic approach to the problem.

By Harry Stephens


Discussion surrounding the ‘Noah’s Ark Problem’ (Weitzman 1998, Perry 2010, Small 2011) – a parable for conservation triage, has received heightened attention in recent years. This corresponds to an accelerated increase in species loss worldwide and subsequent costs associated with protecting many that are threatened (Butchart et al 2010). In conservation, ‘triage’ is the prioritisation of limited resources to maximise returns, relative to the goals, under a constrained budget (Bottrill et al 2008). Practically, it entails treating the ‘most valuable’ first, then dedicating fewer resources or abandoning the ‘less valuable’. The problem lies in taking values from an array of professional backgrounds, then determining comprehensive conservation objectives and management practices from these. Humans differ in their interest and attitude toward nature and naturally, approaches will be conflicting.

Obtained from

A traditional Noah’s ark scene from which modern day triage is based. Obtained from

The meaning of ‘value’

Fundamental to triage is recognition that scarce resources should not be wasted on the severely injured as they are unlikely to recover – we have to set priorities based on economic, ecological and aesthetic factors (Small 2011, Arponen 2012). There is not ‘one fits all’ criterion to determine where resources are allotted, as the definition of ‘conservation benefit’ depends on a various set of human values and beliefs. For example, the conservation scientist’s ‘value’ of a species generally refers to ecological or functional importance and is the key factor in prioritisation (Perry 2010). However, politicians may view a species based on economics, public expectation or aesthetics, sometimes dividing scientists and policy makers (Wittmer et al 2013). This has been observed in Australia and New Zealand, with the Office of Environment and Heritage and DOC respectively, demonstrating the difficulty in establishing an appropriate basis for decision-making around threatened species (Kilham and Reinecke 2015).

Science alone cannot dictate decision-making

Often, it has been suggested that prioritisation is not a scientific matter; rather it depends on what is valued (Arponen 2012). Furthermore, the fact that most funding for conservation comes from public sources (AEDA 2012), justifies people having more input into triage style decisions. Scientific research alone cannot be a robust foundation on which to implement conservation decisions, as it is based on imperfect information in a dynamic environment and thus, will always be questioned by political, economic and public bodies (Marris 2007, Kilham and Reinecke 2015). There is also uncertainty regarding species biology and population dynamics (Marris 2007, McDonald-Madden et al 2008, Arponen 2012), which has associated ecological risks like species interaction disruptions if science was to ‘get it wrong’. Even the most thoroughly studied organisms like Drosophila spp. have only been observed over a relatively short evolutionary time and there is still a lot to learn; the influence of a changing climate means that the cost and benefits of preserving species is also changing (Arponen 2012).

Species appeal and people power

Humans are programmed to like certain beautiful or decorative features of nature like flowers, fur, feathers and antlers (Small 2012). The idea of using charismatic or flagship species bearing these appealing characteristics to support other projects has received little acknowledgement from the scientific community (Andelman and Fagan 2000, Small 2012). A study by Brambilla et al (2013) on Italian bird species even suggested that conservation based on appeal could see species more susceptible to human influence from an Anthropogenic Allee Effect, exacerbating their threatened status.

However, species appeal may be the most effective driver in generating conservation dollars. Flagship, iconic and charismatic species like Grizzly bears (Ursus arctos), Californian Condors (Gymnogyps californiacus) and many large, African mammals may not have as much of a perceived value ecologically, but their appeal produces revenue from tourism and hunting, among other means (Arponen 2012). They also serve as highly visible examples of global conservation, and the public is willing to donate toward their management (Clough 2010, Small 2011). Indirectly, they are important for education and raising awareness which together increase the value of ecosystems and assist in funding projects for their more ecologically beneficial relatives (Perry 2010, Bennett et al 2015).


Just as Noah was limited by space aboard his Ark, decision makers are limited in the amount of biodiversity they can apply resources to. The ultimate objective is to preserve biodiversity, though the approach needs to equally recognize the biological, social and economic elements that reflect ideas of the involved parties. Tools like the Project Prioritisation Protocol (PPP) (Joseph et al 2008, Kilham and Reinecke 2015) are widely used and integrate these aspects based on trade-offs of ecological benefit, cost, success and species value resulting in a rank-ordered list of management actions. Inclusive tools such as the PPP are likely to become more common, as subjective and value-driven opinions concerning priority setting cannot be formed without unbiased consideration.


Andelman, S. J. and Fagan, W. F. 2000. Umbrellas and Flagships: Efficient Conservation Surrogates or Expensive Mistakes? National Academy of Sciences. (97) 11:5954-5959.

Applied Environmental Decision Analysis research hub (AEDA), 2012, On triage, public values and in­formed debate. Decision Point, No.65, p. 4.

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Joseph, L. N., Maloney, R. F., O’Connor, S. M., Cromarty, P., Jansen, P., Stephens, T. and Possingham, H. P. 2008. Improving methods for allocating resources among threatened species: the case for a new national approach in New Zealand. Pacific Conservation Biology. 14:3.

Kilham, E. and Reinecke, S. 2015. “Biggest bang for your buck”: Conservation triage and priority-setting for species management in Australia and New Zealand. Invaluable Policy brief 0115.

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Wittmer, H. U., Serrouya, R., Elbroch, M. and Marshall, A., J. 2013. Conservation strategies for species affected by apparent competition. Conservation Biology. 27:2. 254-260.


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