If there is no direct or indirect information available about a species’ current status or possible threats, this species is listed as Data Deficient (DD) on the Red List. The information about the species is so uncertain that both Least Concern (LC) and Critically Endangered (CR) are plausible categories.

Species listed as DD are of high priority for the Red List, as we have no information on whether these species have a high or low risk of extinction, or whether they may already be extinct. Therefore, we seek to obtain as much information on these species as possible, so that we will be able to categorise them.

Currently, 38 species are listed as DD on the IUCN Red List: