what's the difference between a bird and a letter. migrating birds appearing as dots on airplane radar screens used to be a mystery and the dots were referred to as "angels" angel in Greek: messenger between a bird and a person. phylogenetically, the basal ganglia system deep within the brain is ancient and serves as the predominant motor system for birds and in humans is believed to be involved in automatic movements of eating, posture, walking, swinging arms (I initially mistyped 'winging arms') cardinal at my window, incessantly bangs into glass, hovers in fluttering suspension, back to tree till next propulsion into pane, seemingly oblivious to the pain he must be causing for the sake of this engagement with himself that he appears to believe he's having with another bird next