He was only 6-7 feet over head of me, and I was happy that it didn't fly away. Looking down on the ground I found the reason, a dead squirrel lying in the grass next to the pavement. My theory is that the hawk had previously killed the squirrel but had not had time to finish it, and now the hawk waited impatiently for me to get going so that he could finish his or her meal.
On the way back I looked under the tree. No sign of either squirrel or hawk.