The female has now laid her fourth, and likely penultimate, or final egg.  The pair stays close to the nest box with the female performing over 2/3’s of the incubating duties.  The male is seen nearby the nest and frequently does a flyby on any nearby intruders to let others know that they are not the least bit welcome in the air space around the Clock Tower!  This image shows the male after making numerous aerial loops preparing to land atop the ball at the peak of the weathervane.