What is this? Is this pecking or something else?

[Wlorraine]

The first hen is fine (the one on the left). The hen that is in front looks awful. Looks to me like somewhat is pecking at her. But I have no rooster. I have 3 ducks, 3 bantam hens, and 5 guineas. I afraid I will lose another bird. We lost a large rooster the same way last summer. And now here we go again.

 

[Judy]

Hens will also peck and pull feathers. Too little space and too little protein in the diet are the most common causes. She could have a bad case of lice / mites, which will kill a bird if severe enough. There are other skin / feather conditions as well. I've never had guineas or ducks; I have no idea, really, but I wonder if one of them is doing some damage.

http://ohioline.osu.edu/vme-fact/0018.html