Eli5 Why do birds have such twitchy movement?

Question

Compared to mammals, birds seem to have this jerky, almost robotic quality to the way they move. I was wondering if there’s any explanation for this

In: 1836

Answer 1

Taking the questioner seriously, birds mostly have separate vision on the left and right but each eye had a wide angle of vision. The head control for a comparatively light head allows rapid movement to closely examine a new interest or danger and it is my belief that they cannot scan slowly like humans and most if not all large mammals.