Thanks! It's good to be here, and I'm glad to hear I might be on the right path!
We're actually down to 1 rooster. The other was quite aggressive with the new chicks, not to mention the dominance issues between the two. This guy is quite big and I've seen more than one feather lost as a result...
Quick update. After realizing it might be my rooster at the end of my post last night, I checked another one of the new girls today, his favorite, and she's got similar bald spots but also on her sides. After researching that specifically, I'm even more convinced this is the likely cause...
tl;dr Trying to figure out what this is
Backstory: In early winter last year, my two adopted girls started what I thought was molting, but they only seemed to lose feathers between their back and tail area.
Here:
Older girls around Jan-Feb (started maybe Nov or Dec)
new girl today...