It helps create suspense because a vulture is not a very likely used animal to portray something very pleasant such as a humming bird. A vulture is more looked upon as a threat or very creepy .
Most common Archetypal characters in Literature are:
-The Hero
-The Villain
-The Journey
-Doppelganger
-The Innocent Youth
-The Mother Figure
If you need the definitions, go to the website literarydevices
they have good definitions.