IUCN Red List Is Incomplete: Remote Sensing Data Shows Hundreds More Species in Danger

The International Union for Conservation of Nature (IUCN) Red List has been the standard for determining the effects of a changing world on biodiversity since it was founded in 1964. But a recent study has revealed that more than 200 bird species in six rapidly developing regions are at risk of extinction even though they are not included in the IUCN Red List.

The Duke University-led study published in the peer-reviewed journal Science Advances, used remote sensing data to map recent land-use changes that are reducing suitable habitat for more than 600 bird species in the Atlantic forest of Brazil, Central America, the western Andes of Colombia, Sumatra, Madagascar and Southeast Asia. Out of these 600 species, only 108 are to be found on the IUCN Red List and identified to be in danger of extinction.

"Good as it is, the Red List assessment process dates back 25 years and does not make use of advances in geospatial technologies," stated Stuart L. Pimm, Doris Duke Professor of Conservation Ecology at Duke's Nicholas School of the Environment. "We have powerful new tools at our fingertips, including vastly improved digital maps, regular global assessments of land use changes from satellite images, and maps showing which areas of the planet are protected by national parks."

In his support of the study, Pimm revealed that 210 of the species face accelerated risks of extinction and 189 of them should now be classified as threatened, based on the extent and pace of habitat loss documented by recent remote sensing. Pimm emphasized that an incomplete IUCN Red List is causing scientists and policymakers to overlook priority areas for conservation.

Natalia Ocampo-Peñuela, the new study's lead author, who received her Ph.D. from Duke earlier this year, stated that though the Red List currently includes estimates of the size of a species' geographical range in its assessment process, it fails to account for how much preferred habitat remains within that range.

"Some bird species prefer forests at mid-elevations, while others inhabit moist lowland forests," she said. "Knowing how much of this preferred habitat remains, and how much of it has been destroyed or degraded, is vital for accurately assessing extinction risks, especially for species that have small geographical ranges to begin with. But it's ignored in the current Red List assessment process."

Ocampo-Peñuela concluded by asserting, "Natural habitats in the most biodiverse places on Earth are disappearing, pushing species toward extinction a thousand times faster than their natural rates. Preventing these extinctions requires knowing what species are at risk and where they live," she said. "With better data we can make better decisions, and have a greater chance of saving species and protecting the places that matter."