Corvo Island has, per square kilometer, the larger amount of endemic species of the Azores. In total, there are 95 endemics species, of which 59 are from Azores, 19 from Macaronesia and 17 from Europe. There are also endemic invertebrates that gives this island a unique richness. Concerning terrestrial arthropods are registered 24 endemics of the Azores and 6 of Macaronesia. Stands out the presence of the rare endemic butterfly, the Hipparchia azorina occidentalis (borboleta-castanha) that only exists in Corvo and Flores Islands. There are also registered eight species of bryophytes, being one of them, Echinodium renauldii, considered one of the most endangered in the world.
The humid zone of the Caldeirão was classified as Ramsar Site in 2008, being part of the Natura 2000 Network, as its Costa (coast).