According to the U.S. Fish and Wildlife Service, twenty-one endangered California condors (Gymnogyps californiensis) have died of avian influenza strain H5N1.  The losses including eight breeding pairs is estimated to set back the rehabilitation program by at least ten years. Condors only mature at eight years and a pair will produce one viable chick on alternate years.

It is evident that all remaining condors in captivity should be vaccinated against H5N1. A program to trap and immunize wild condors should be considered if mortality continues or in anticipation of a subsequent outbreak.

The 2021-2023 panornitic of avian influenza strain H5N1 clade 2.3.4.4b with Eurasian genes has affected a wide range of free-living species. Among the most endangered include the Barnacle goose (Branta leucopsis) that nests on Svalbard Island of Norway but overwinters in Scotland and the Humboldt penguin (Spheniscus humboldti) of Southern Peru. It is estimated that a third of the previously declining populations of both species have died from HPAI.  Colonies of the Dalmatian pelican  (Pelicanus crispus) have been reduced in large numbers on lakes in Northern Greece and Macedonia.