The IUCN determines which animals are at risk of extinction. But is it up to the job?

Scientists on conservation frontlines publish concerns that the red list of threatened species is outdated and unreliable

Alice Hughes found the strange reptile in March. It was hanging by its long, slender fingers from the limestone wall of a cave in northern Thailand: a grey-brown gecko she believes belongs to a species unknown to science.

Hughes, a conservation biologist at the University of Hong Kong, is part of a group researching limestone systems, valuable arks of biodiversity pocked with deep caves that can shelter rare species. Many of those species are not known to science," she says. This was the group's second new discovery after a neon-green cave gecko found in Myanmar in 2017.