It is the first study of its kind on reptiles and involved 961 scientists in 24 countries on six continents and lasted 15 years.
Similar global assessments for other animal classes found that 40.7% of amphibians, 25.4% of mammals and 13.6% of bird species are threatened with extinction.
“Through work like this, we publicize the importance of these creatures. They are part of the tree of life. Like any other that also deserves attention.”
Habitat loss due to logging, agriculture and urbanization, as well as competition with invasive species, is the main threat to reptiles. Other factors have played a role for certain species such as their use in traditional medicine. The climate crisis also poses an uncertain challenge, the study adds.
Threats to reptiles were most acute in forest environments, according to the study.
Crocodiles and turtles were among the most endangered species in need of targeted conservation efforts, with around 57.9% and 50% of those assessed being threatened, respectively, according to the study.
The authors said a lack of data on reptiles and their habitats had limited conservation efforts, although they noted that many measures put in place to protect mammals, birds and amphibians would also protect reptiles.
The researchers applied the International Union for Conservation of Nature’s Red List of Threatened Species criteria to 10,196 reptile species. The team found that 1,829 (21%) of the species were threatened with extinction (classified as vulnerable, endangered or critically endangered according to IUCN criteria).
Widespread and highly publicized species such as the king cobra were threatened, the survey found.
“It was suspected that it might be in decline, but without the Global Reptile Assessment we wouldn’t have known it was actually vulnerable,” said co-author Neil Cox, unit lead. Biodiversity Assessment, a joint initiative of IUCN and Conservation International in Washington, DC.
Delegations from governments around the world are expected to meet in Kunming, China, later this year to agree on a new biodiversity action plan.