Hen being chased back into coop by the rest of the flock

[Kodapop17]

Hey everyone, I did some searching on here and could not really find the situation I am having. I have 7 birds (6 hens and a rooster) The coop they are in currently is almost 200sqft and the outdoor run is a little larger. One of my oldest hens (3 years old) the last couple weeks has started to get bullied by all of the other birds in the flock but what is strange is they do not seem to be attacking her relentlessly but rather they seem to be jumping on her and chasing her until she runs back into the coop and then they leave her alone until she tries to come back outside again (which she has basically stopped doing at this point). I have been unable to identify a primary aggressor although it seems like it might be the rooster (he is great with all the other hens and allows me to pick him up without issue, has shown no other aggression) I am wondering if it is related to him mating with her. Not sure how to handle the situation and was hoping someone here may have some advice.

Thanks

 

[aart]

Might try isolating the male and see what happens.
Does your run have 'hiding' places?
Good ideas for hiding places:
https://www.backyardchickens.com/threads/a-cluttered-run.1323792/

 

[Kodapop17]

I do not but that's a good idea for a consideration Right now I have them all free ranging in two separate areas (the main flock in one and the bullied bird in a different) they both have there own food and water dishes as well as trees, shade, sun, and plenty of grass to roam around in. I am hoping boredom may be a contributing factor as the bullied bird is walking around scratching and pecking at the grass just normal and even took some treats so it does not seem like she is ill. Probably a little bit naive on my part but I am hoping some time apart in the free ranges will help

 

[Perris]

One of my oldest hens (3 years old) the last couple weeks has started to get bullied by all of the other birds in the flock but what is strange is they do not seem to be attacking her relentlessly but rather they seem to be jumping on her and chasing her until she runs back into the coop and then they leave her alone until she tries to come back outside again (which she has basically stopped doing at this point). I have been unable to identify a primary aggressor

the bullied bird is walking around scratching and pecking at the grass just normal and even took some treats so it does not seem like she is ill

In my experience, when this has happened (everyone in the flock driving off one bird that has hitherto been a normal member of the flock) the bullied bird has something that the rest view as a threat; they don't want her near, so drive her away. There is no aggression if she stays away. My flock tolerate a bird with an idiopathic illness (one that is no threat to them, e.g. a reproductive tract issue) but not one that has something they think they might catch from it. So I would examine her for symptoms of illness and signs of parasites, even if she seems OK; chickens are very good at hiding illness, to avoid attracting the attention of predators.