I had an Ameraucana do this also but it caught up and feathered out eventually. Still had never seen it except from hatchery birds but he wasn't from a hatchery.
Ericinga - Yes, these are from a hatchery. We got Wyadottes for their cold hardiness - this one will need feathers soon. We can easily be in the 40's at night by Sept. (I'm in the mountains). How long did it take for your Ameraucana to eventually feather out?