As of December 2020, the International Union for Conservation of Nature (IUCN) lists 46 data deficient avian species.
[1] 0.47% of all evaluated avian species are listed as data deficient.
No subpopulations of birds have been evaluated by the IUCN.
This is a complete list of data deficient avian species evaluated by the IUCN.
Includes petrels and albatrosses ("Crane-like")