My Plymouth Red is losing feathers around her neck. She will be one year in February. The feathers are around on the ground and not being eaten by the two other chickens (Sicilian Buttercup & Dutch Bantam) so I determined it's not a calcium deficiency. I have not witnessed any bullying, but it occurred behind closed doors in the coop. It happened last night as yesterday she was fine.
Approx one week ago she "flew the coop" for the first time and didn't come home one night. She stayed in the neighbors yard overnight but was promptly found the next morning. Since then, I believe she has not laid any eggs as I am only getting one per day as opposed to the usual two. I also changed the shavings in the coop to hay (as I had some) the day we found her. Lastly, I "grounded" her after she returned and she hasn't free ranged in a few days. We inspected her for mites, lice and sores and don't see any. We also dusted about three months ago.
I have a feeling it's boredom pecking or stress from a week ago, but wanted the opinion of the rest of the flock.