20 percent of reptiles, from king cobras to geckos, are endangered

According to the first-of-its-kind global reptile assessment, about 20 percent of reptile species are threatened with extinction, largely due to human taking their habitat for agriculture, urban development and logging.

The study found that at least 1,829 species of reptiles, including lizards, snakes, turtles and crocodiles, from inch-long geckos to the legendary king cobra, are endangered.

Study, published Wednesday in Nature, adds another dimension to the vast body of scientific evidence pointing to a human-induced biodiversity crisis similar to climate change in the enormous impact it could have on life on Earth. “This is another drumbeat on the road to environmental disaster,” said Bruce Young, co-leader of the study and senior scientist at NatureServe, a nonprofit environmental research group. Such a collapse threatens people because healthy ecosystems provide essentials such as fertile soil, pollination and water supply.

Among reptiles, tortoises, nearly 60 percent of whose species are endangered, and crocodiles, half of which have been particularly hard hit. In addition to habitat loss, both groups are depleted by hunting and fishing.

But the results also brought a sense of relief. Scientists knew much less about the needs of reptiles compared to mammals, birds and amphibians, and they feared that the results would show that reptiles were escaping as they required other conservation methods. Instead, the authors were surprised at how neatly the threats to reptiles overlapped with the threats to other animals.

“Protecting reptiles is not difficult, we have all the necessary tools,” Dr. Yang said. “Reduce deforestation, control illegal trade, increase agricultural productivity so we don’t have to expand our farmland. All this will help the reptiles, as well as many, many other species.”

The authors found that climate change played a role in the threat faced by 10 percent of species, suggesting that it is not currently a major driver of reptile extinction. But the implications may be underestimated, Dr. Yang said, because scientists simply don’t know enough about many reptiles to determine whether they are threatened by global warming in the short term.

What is clear is that the toll of climate change, reptilian and otherwise, will rise sharply in the coming years if world leaders fail to properly curb greenhouse gas emissions, which mainly come from the burning of fossil fuels. Last September, the Komodo dragon, the world’s largest lizard, was classified as critically endangered in large part due to rising temperatures and sea levels caused by climate change.

The reptile assessment involves 52 authors, with more than 900 experts from all over the world participating. It took over 15 years to complete, in part because funding was hard to come by.

“Reptiles are not charismatic for many people,” said Dr. Young. “There was just a lot more focus on some of the more furry or feathery species.”

Ultimately, the team evaluated 10,196 species. Between 2004 and 2019, at 48 workshops, groups of local experts gathered and assessed the species one by one. The results for each reptile were analyzed by a scientist familiar with the species but not involved in the assessment, and then again by the International Union for Conservation of Nature’s Red List of Threatened Species, the most comprehensive global catalog of animal health. and types of plants.

21% of species have been found to be endangered, with reptiles at higher risk than birds (of which about 13% of species are endangered) and slightly less than mammals (25%). Amphibian species that have suffered from severe diseases in addition to other consequences are faring much worse: about 40 percent of the species are endangered.

The study confirmed the results previous analysis this extrapolated the extinction risk of reptiles based on a random representative sample.

The authors found that if all reptiles were threatened with extinction, they would take 15.6 billion years of evolutionary history with them. “Now that we are aware of the threats that every reptile species faces, the global community can take the next step by integrating conservation plans with a global political agreement, investing in overcoming an often-over-underestimated and severe biodiversity crisis,” said Neil Cox, co-lead author research, and leads the Biodiversity Assessment Panel, a joint initiative by IUCN and Conservation International to expand the coverage of the Red List.

This year, the countries of the world are developing a new global agreement to combat biodiversity loss. While the threats to species are clear – such as deforestation for beef cattle and palm oil production – it is much harder for countries to agree on how to stop them. A meeting in Geneva last month ended in disappointment for many scientists and activists, who described a lack of urgency from governments after two years of pandemic-related delays. Organizers have added another meeting in June in hopes of making progress ahead of the final meeting in Kunming, China later this year.

The reptile survey has identified hotspots for endangered reptiles in Southeast Asia, West Africa, northern Madagascar, the northern Andes and the Caribbean.

The assessment fills an important gap, said Alex Pyron, an evolutionary biologist at George Washington University who focuses on reptile and amphibian biodiversity and was not involved in the study. “This allows us to paint a much more detailed picture than was possible before,” Dr. Pyron said.

The scientists said they were particularly struck by the fact that habitat loss due to deforestation, agriculture and other causes poses a much greater threat to most reptiles than factors such as pollution and climate change. Dr. Yang, one of the leaders of the study, said addressing such problems would require significant changes in human behavior and the economy, given that “human consumption is the ultimate cause.”