A Vulnerable species is one which has been categorised by the International Union for Conservation of Nature (IUCN) as likely to become Endangered unless the circumstances threatening its survival and reproduction improve.

Vulnerability is mainly caused by habitat loss or destruction. Vulnerable species are monitored and are becoming threatened. However, some species listed as "vulnerable" may in fact be quite abundant in captivity, an example being the Venus Flytrap.^{[citation needed]}