In December 2020, the International Union for Conservation of Nature (IUCN) listed 798 vulnerable avian species. Of all evaluated avian species, 7.3% are listed as vulnerable. No subpopulations of birds have been evaluated by the IUCN.
For a species to be assessed as vulnerable to extinction the best available evidence must meet quantitative criteria set by the IUCN designed to reflect "a high risk of extinction in the wild". Endangered and critically endangered species also meet the quantitative criteria of vulnerable species, and are listed separately. See: List of endangered birds, List of critically endangered birds. Vulnerable, endangered and critically endangered species are collectively referred to as threatened species by the IUCN.
Additionally, 53 avian species (0.48% of those evaluated) are listed as data deficient, meaning there is insufficient information for a full assessment of conservation status. As these species typically have small distributions and/or populations, they are intrinsically likely to be threatened, according to the IUCN. While the category of data deficient indicates that no assessment of extinction risk has been made for the taxa, the IUCN notes that it may be appropriate to give them "the same degree of attention as threatened taxa, at least until their status can be assessed".
This is a complete list of vulnerable avian species evaluated by the IUCN. Where possible common names for taxa are given while links point to the scientific name used by the IUCN.
Mesites
Penguins
Procellariiformes
Procellariiformes includes petrels and albatrosses. There are 30 species in the order Procellariiformes assessed as vulnerable.
Albatrosses
Procellariids
Storm petrels
Matsudaira's storm petrel
Monteiro's storm petrel
Gruiformes
There are 26 species in the order Gruiformes assessed as vulnerable.
Trumpeters
Dark-winged trumpeter
Cranes
Rallids
Bustards
Parrots
There are 53 parrot species assessed as vulnerable.
Cockatoos
Salmon-crested cockatoo
Blue-eyed cockatoo
Psittacids
Suliformes
Pigeons and doves
Pelecaniformes
Galliformes
There are 46 species in the order Galliformes assessed as vulnerable.
Cracids
Megapodes
Phasianids
New World quails
Guineafowl species
White-breasted guineafowl
Struthioniformes
Bucerotiformes
Accipitriformes
Accipitriformes includes most of the diurnal birds of prey. There are more than 20 species in the order Accipitriformes assessed as vulnerable.
Accipitrids
Anseriformes
Anatids
Owls
There are 27 owl species assessed as vulnerable.
Barn-owls
Strigidae
Charadriiformes
Falconiformes
Coraciiformes
Passerines
There are 337 passerine species assessed as vulnerable.