The frustrating thing about the dog is that this behavior had been stopped when she was a puppy and she didn't even look at chickens for almost a year, could have cared less.
Then she had a litter of pups and of course the puppies would chase the chickens, but not in a mean way, just a game. To a puppy chickens are the ultimate squeaky toy, and sometimes the chickens were in the puppy food too, so there was a little food aggression to work on. So while I am concentrating on correcting the pups mom decides that she needs to get in on the act and chase the chickens too.
At first I thought maybe she was trying to chase the chicken away from her puppy, wishful thinking on my part. I don't think that was her intention at all.
When I have found her with a bird that is wounded or dead it it almost as if she is guarding it. She will carry it either under the barn or onto a pile of hay that she likes and they lay there with it besides her. The other dog can't touch it. I am not sure if she IS truly guarding it because it is injured or if she is guarding her next meal. But she doesn't eat them.
Livestock guarding dogs have next to no prey drive and they are very protective of their charges so it is hard to read her. I did put the electric collar back on her a few times when I was home, and when the collar is on she doesn't have any interest in chickens. Smart dog, darn it.
It has been about 3 weeks since the last fatality and she is with the chickens all day. I am hoping that my beating her with the dead bird last time made an impression. She is a very tender hearted dog and really wants to please me so maybe she got the point.
We will be fencing more pasture in the next month or two so I am hoping that more room with her to run with her goats will help too. Maybe she is just bored.