G.G.Sill, A Handbook of Symbols in Christian Art , Touchstone, p. 59. The bald spot on Francis's head is not male pattern baldness. It is a tonsure, which is a deliberate removing of hair from the top of the head. The first ordination a person could receive was Tonsure. It was the first of the minor orders and functioned as a reception into the clerical state.
Major orders are deaconite, priesthood, and episcopacy.
There would have been legal consequences because a cleric would be subject to church law and courts rather than those of the state. Always look at the hands, because they are often as expressive as the face. Here one hand is down and open. It shows a peaceful trust that welcomes the birds presence but also their attention. The other hand is raised with three fingers fully extended and the last two folded.