BirdLife International says 200 migratory species face extinction, with shorebirds and seabirds suffering particularly severe losses.
Australia has recorded 354 positive bird flu events in wildlife, including 203 in South Australia, according to official figures.
Warning comes days after Australia confirmed its 1st case of bird flu in a mammal.
Flowers can become points of infection when different bee species begin sharing the same plants as glacier retreat changes ecosystem.
Authorities launch mass penguin vaccination in Victoria as bird flu reaches a mammal for the first time in South Australia.