The continual increase in human activity and land use will put more than 1,700 species of birds, mammals and amphibians at risk of extinction by 2070, according to a recent study by Yale ecologists.

“Our study shows that depending on the specific future pathway, land-use changes will have severe consequence for biodiversity,” said Walter Jetz, co-author of the paper and professor of ecology and evolutionary biology and of forestry and environmental studies.

In the study, which was published in the journal Nature Climate Change on March 4, Jetz and co-author Ryan Powers, a former postdoctoral fellow in the Jetz lab, used glocal decadal land-use projections up to the year 2070 to evaluate the potential losses in habitat and to assess the risk of extinction for approximately 19,400 species.

Jetz explained that the 19,400 species were selected for the study because Jetz and Powers had the distribution and habitat data for those birds, mammals and amphibians. According to the study, the study identified significant declines in habitat for approximately 1,700 species worldwide as a consequence of land-use change alone. The research also highlights certain South American, Southeast Asian and African countries in need of particularly proactive conservation planning.

“Our findings establish a vital link between plausible socioeconomic futures and their implications for biodiversity,” Jetz explained. “Specifically, they provide a tracking of how political and economic decisions and their associated changes to the global land cover are expected to cause population loss in species worldwide.”

The study operates through a projection of moderate changes in human land-use and predicts that the 1,700 species of concern will lose roughly 30 to 50 percent of their present habitat ranges by 2070. These species of concern include 886 species of amphibians, 436 birds and 376 mammals.

Several species are highlighted in the research, including the Lombok cross frog, whose range is restricted to the Indonesian islands of Lombok and Bali and who is projected to lose half of its suitable habitat range by 2070. Another species, the Nile lechwe, is expected to be moved to critically endangered status by 2060.

To help their audience develop a visual understanding of the data and its significance, Jetz and Robert Guralnick, a professor at the University of Florida, along with a team of students and faculty from across the country — including Powers — have created a website called Map of Life. On Map of Life, visitors can scroll through species or look for specific species and examine their current ranges and their projected ranges by a specific year. The projections show as splotches of bright color on a map, and toggling between years like 2015 and 2070, the projections for most species show a major shrinkage of viable habitat.

“Through the integration with Map of Life, these species’ consequences can be examined by anyone,” Jetz said. “This begins to enable a transparent accounting of the biodiversity implications of future political and economic decision-making, something the conservation organizations or other stakeholders can use as they make their case.”

The study was funded by grants from the National Science Foundation, the Natural Sciences and Engineering Research Council of Canada and the National Aeronautics and Space Administration.

The study was a four-year effort, according to Jetz.

Madison Mahoney | madison.mahoney@yale.edu