I found this exercise to be more difficult. My brain wanted to go back and draw the whole outline of the sparrow. I stuck with the process. I really focused on the negative space and it made a huge difference as far as proportion and the relationship of the wing, head and tail to the body. I am pleasantly surprised with the results.
This exercise was really hard for me. My eyes constantly wanted to shift down to the paper. By the fourth drawing I had better control at concentrating on the subject. I also found myself rushing through the drawing. I will need to practice more so that I can control this.