As of September 2016, the International Union for Conservation of Nature (IUCN) lists 783 data deficient mammalian species. 14% of all evaluated mammalian species are listed as data deficient. The IUCN also lists 30 mammalian subspecies as data deficient. Of the subpopulations of mammals evaluated by the IUCN, four species and/or subpopulations have been assessed as data deficient.