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

Muscle fibers come in three main types. It basically comes down to slow and fast twitch. Slow twitch gives more power and longer duration, fast twitch gives just that, fast contraction but tire quickly. Birds typically have more of the twitch type that cause the quick jerky movements.