Overcoming the Linnean shortfall: Data deficiency and biological survey priorities

Abstract

Knowledge of biodiversity is woefully inadequate. Only a fraction of the planet's species has been described by science (the “Linnean shortfall”). Even for described species, scientists often have only fragmentary information about their distributions (the “Wallacean” shortfall). These shortfalls in biodiversity knowledge place serious limitations on the ability to conserve biodiversity in the face of the ongoing extinction crisis. Here, I test the hypothesis that data deficiency may be used to guide surveys and inventories to regions that would increase the probability of discovering new species. I compiled global distribution maps for all Data Deficient amphibian species (species described up to 2004) and constructed a Data Deficiency (DD) surface (the DD surface was based on distribution information obtained from the IUCN Red List). Then, I compared the type-locality sites of new amphibian species descriptions (species described between 2005 and 2009) with the DD surface in order to check if new species discoveries were significantly more abundant within the DD surface or not. Even though the amphibian DD species surface covers only 8% of Earth's land area, 79% of the amphibian species discovered between 2005 and 2009 were within the DD surface. The results suggest that directing surveys towards areas of known data deficiency will likely result in the discovery of species new to science, helping to address the Linnean shortfall. Incorporating DD information from the IUCN Red List may provide an efficient methodology for strategically targeting surveys and inventories, maximizing the chances of obtaining high conservation benefits from them, and helping minimize the costs associated with such endeavours.