Lake Tear of the Clouds
Gregory O’Mullan Andrew Juhl hiked into the High Peaks of the Adirondacks to collect water samples at Lake Tear of the Clouds and then downstream from the source to Newcomb. Source: Riverkeeper

Two in every five amphibian species in the world, or around 40% of 8,000 species, are categorized as threatened—a much higher percentage than other classes of animals, a new assessment has found.

In a paper published in the journal Nature on Wednesday, researchers looked at 20 years’ worth of data on nearly every amphibian species on Earth, compiled by more than 1,000 scientists—a follow-up assessment to a similar one conducted in 2004.

The paper finds that amphibians around the world are “deteriorating rapidly”—and that climate change poses much more of a risk to them than it did in the first analysis, responsible for 39% of species getting closer to extinction compared to just 1% in the 2004 work.

“They don’t have any protection in their skin,” Patricia Burrowes, a professor of biology at the University of Puerto Rico, told NPR. “They don’t have feathers, they don’t have hair, they don’t have scales.”

(NPR, NBC, USA Today, Washington Post $, AP)