is it cannibal behavior

[lady birds]

I only have 6 hens in my coop/ run: 2 Ameraucana, 2 black Maran, 1 Faverolle and 1 blue andalusian. The later 2 of these stayed in the brooder a bit longer as they were 1 and 2 weeks younger (DOB Mar-7 12 and 18/ 2014). It was a bit of push away for the younger newcomers and then all was FINE. We went away for a week and they were cared for the a live-in dog sitter. I noticed both times when I returned the rim of the water was dirty and the Faverolle's neck feathers were dirty. There was a heat wave while we were gone. THE PROBLEM IS THE YOUNGEST, Andalusian, is picking all the feathers off OLDEST, Maran. I NEVER SAW THE BEHAVIOR STARTING BUT SHE CRIES OF I TOUCH HER
What shall I do???

 

[Judy]

Please look at this post and its links, which discusses much the same problem:

https://www.backyardchickens.com/t/922400/pecking/0_20#post_14045742

Hopefully, since this is such a new thing and only one bird doing it, you will be able to get it stoped. I wish you luck!