Most people feel braver, or sometimes they have no logic to their actions.
Explanation:
For example, sometimes if im ever half awake, or between slepping and awake, my mind starts to just have weird thoughts, like stuff I wouldnt do, like fight someone, or just randomly ask someone out.
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 .