Call them the cinderellas of conservation, the 'known unknowns' - species that we know are out there, but which haven't been discovered yet. Conservationists are quite rightly focused on saving the many known species, which are already under threat. But what about losing a species before we even have a proper handle on its existence - that would be tragic, too.
So how do you go about saving these 'missing species'? One approach that conservationists take, so as to apply their limited resources for the maximum effect, is to concentrate on so-called 'biodiversity hotspots'. These are the parts of the globe that we know to be rich in a diversity of life, but which are also under threat from habitat loss. But how do we know if those biodiversity hotspots have lassoed themselves firmly around those unknown 'missing species', that we have yet to discover?
You might think that identifying whether such undiscovered species lie within these high-priority areas was nigh on impossible. But that's just what an international research team believe they have done, with the release of a study into nature's 'known unknowns', published in this week's Proceedings of the National Academy of Sciences.
Lead author of the study, Lucas Joppa, now at UK-based Microsoft Research, in Cambridge, phrased the problem like this : 'If we don't know how many species there are, or where they live, then how can we prioritize places for conservation? What if the places we ignore now turn out to be those with the most unknown species?'
The team, which also included Stuart Pimm, a Professor of Conservation from North Carolina's Duke University, tackled this thorny issue by building a computer model of the rates of discovery of new flowering plant species, across the globe and over the decades. Flowering pants are considered a good proxy for an area's wider biodiversity.
This model was then used to infer the proportion of species that remain undiscovered, for all parts of the globe. The authors then cross-referenced the places where the model indicated many unknown species were, with the already-identified biodiversity hotspots. Significantly, this produced a good match - 70% of the unknown species appear to be in such hotspots. These include parts of Central America, from Mexico to Panama; most of Colombia; the Ecuador/Peru region; a zone southwards through Paraguay and Chile; southern Africa; and much of Australia.
"It was a huge relief that those places in which we are already investing our resources are also those which house the majority of the world's undiscovered species," said David Roberts of the University of Kent. 'It didn't have to turn out that way!' The bad news is that, despite the conservation focus on those areas, they are by definition some of the most threatened parts of the planet.
Taking a glass half-empty slant on the research results, Pimm said ''We show that the majority of the world's 'missing species' are hiding away on some of the most threatened landscapes in the world. This considerably increases the number of threatened and endangered species around the world.''
Top Image: Australia rain forest © Magann