ما هي الطيور المعرضة للأنقراض ؟
For a species to be considered endangered by the IUCN it must meet certain quantitative criteria which are designed to classify taxa facing "a very high risk of exintction". An even higher risk is faced by "critically endangered" species, which meet the quantitative criteria for endangered species. Critically endangered birds are listed separately. There are 634 avian species which are endangered or critically endangered. 
facing "a very high risk of exintction