Stork
It depends on the bird.
No.
no
The bird caused the death of the frog by eating it, but the bird's death was accidental and not intentional.
rapidly
A black bird symbolizes death.
No, bird flu is a disease caught from birds.
Crows and Ravens
Bird flue and salmonella
Death rates can change unexpectedly due to disease, wars and catastrophes, or advances in medicine. Birth rates are declining too.
Black swan
No, death is not a disease. Death is a natural and inevitable biological process that occurs as a part of life. While diseases can lead to death, death itself is the cessation of all biological functions.