It used to be required for any man entering the monastery or the clergy to be have their head partially shaved as the first part of the ceremony. The style of the tonsure varied from order to order and from region to region, but one common form was to shave the crown of the head, sort of like imposing male pattern baldness. Long hair was fashionable for men throughout most of history, so the idea behind the tonsure was to defer to Paul:
Does not nature itself teach you that if a man wears long hair, it is degrading to him — 1 Corinthians 11:14
An elderly lady bought a parrot to keep her company. After a week or so she decided the parrot looked a little lonely, so she bought another parrot of the opposite sex to keep it company.
But then she discovered she couldn’t tell the male from the female because they both looked so similar in coloring and size. Then she hit upon a solution. She watched them and when the male mounted the female she snatched it up and pulled all the feathers out of the top of his head.
Later that day the local parish priest came by to see how the lady was doing. When he came in he bowed down and removed his beanie thus exposing his shaved head.
The parrot, observing this, said:
Did she catch you doing it too?