18,000 Animal Species Are Endangered

In 2025, the number of threatened species identified by the International Union for Conservation of Nature and Natural Resources stood at over 18,000. But while animals like critically endangered orangutans or humpback dolphins are getting a lot of attention, the share of threatened mammal species stood at only 7 percent of all threatened animals.

Mammals represented 14 percent of all threatened animals species (defined by the as species listed as either critically endangered, endangered or vulnerable on the Red List) in 2007. Between 2007 and 2025, animal classes with a growing share in endangered species counts included reptiles, insects, fish and molluscs (a class including snails, slugs, mussels, squid and worms), while amphibian endangerment remained at a high level. Almost every fourth endangered species in the world in 2025 is a fish.

While the reasons for the endangerment of insects and fish are well known and include overfishing, pesticide use and monoculture, less is written about threats to reptiles and molluscs. According to the IUCN, many reptile species are concentrated in rainforest regions and are therefore threatened by deforestation. Furthermore, the species are particularly sensitive to environmental changes, including climate change. With molluscs, endangered species are mainly those who live on land and in freshwater. They are threatened by habitat destruction or are being pushed out by invasive species, according to the American Institute of Biological Sciences.