Publication update 3: The SAFE Index – what it is and what it isn’t

A conservationist’s work is all about saving endangered species. We all know that. Most of us in the business are also familiar with the IUCN Red List, which categorises species according to how threatened they are.

But have you ever wondered just how close a species really is to extinction? What does it mean exactly, when a species is endangered? And are all endangered species equally endangered? What if you had a limited amount of resources – a bit of funding here, a few members of staff there, and a whole bunch of species that need saving.

Or perhaps it all comes down to a choice between two different species. They’re both endangered. But you can’t save them both, because the resources you have simply aren’t enough. You have to choose. How do you choose? Wouldn’t you want some method to help you decide which species you should invest your resources and effort in?

This is what the SAFE Index is all about.

Devised by Reuben and his colleagues, this new method outlines a novel approach to determine which endangered species have a higher likelihood of bouncing back from the brink. By comparing actual population numbers against a threshold population number required for long-term persistence, you don’t just identify which species are simply endangered, you can also identify which species can actually still recover.  In fact, the SAFE index better predicted the IUCN threat category of a particular species than percentage home range loss, a previous proxy of how close the species is to extinction.

The SAFE index can go a long way towards helping conservationists when it comes to prioritising and decision-making – after all, it’s a sad truth that conservation is perpetually underfunded, and conservationists are too few and far between. And unless the rest of the world starts taking this seriously, this isn’t likely to change soon.

However, at the end of the day, the SAFE Index is merely a guiding tool, and its usefulness really depends on how you choose to interpret and use it. In anticipation of misinterpretations that may lead to outrage and criticism, we hope that you will take note of the following points:

• The SAFE Index is NOT proposed as a replacement for the IUCN Red List. It is meant to COMPLEMENT the Red List.
• As a tool, the index itself cannot tell you what to do. It merely equips you with the necessary information, provided you have the necessary data to begin with. If you are already focused on saving a species on the ground, we’re not asking you to stop! In fact, you’re doing more than most armchair conservationists are doing…
• We’d like to save everything, but in this era of limited conservation resources, we can’t. The index is based on probability, and some species can bounce back with enabling conditions. The paper is simply saying that species with a more negative SAFE index are more likely to go extinct. Practitioners of conservation triage should therefore take heed.
• The index should not be viewed as simply an ‘either-or’ approach. Besides being used to choose between different species, it can also be used to identify whether a particular species of interest is so close to extinction that it requires immediate attention, or species at tipping points like the tiger. Some species on the brink have bounced back due to conservation efforts. However, do bear in mind that by channelling resources to a species that is closer to extinction, you may be overlooking another species that might have a higher chance of recovery.
• Ideally the index should not be used in isolation, and other relevant factors must be taken into consideration as well to put things into context. For example, a species that is still on the brink despite sustained (and expensive) conservation efforts is not the same as a species on the brink which no one has tried to save just yet.
• The paper’s recommendation of using 5000 (based on meta-analyses of many other population studies) as a threshold is, again, only a guide in the face of uncertainty and insufficient data. Ideally it should only be used for species with larger population sizes that normally occur above that threshold. The threshold should obviously not be used for species that occur at naturally low population sizes of less than 5000. For these species, particularly where data is available, species-specific thresholds MUST be used instead.

Feel free to drop us a line if you have any further questions or comments. We hope you enjoy the paper, and if you work in conservation we hope that you’ll find the SAFE Index useful for what you’re doing! Download SAFE index paper