Rooster aggression towards one hen

[OutInTheStiks]

Our rooster seems to have singled one hen out to chase. Its not a mating chase but more of a "get the heck out of here" chase. Dell, one of our Delawares, was his main girl before going broody back in the late fall. She sucessfully hatched her eggs and then we reintegrated her back into the flock after selling the chicks. She was the top hen in the pecking order before taking her broody vacation. Now she resides somewhere in the middle of the order. There are 11 hens counting Dell with one rooster. The chicken yard they occupy is roughly 200ft by 50 ft. Any thoughts as to why he would want to chase her now?

 

[jeslewmazer]

I would take him out of the flock for about a week and let the girls get their pecking order strait first. He might just being protective and has a new favorite hen. She might take the top back with the roo out of the way for a little while. But the attacks should stop if he is reintroduced to the flock after a short separation.