I would have thought moulting , except that they have already done their moult (at the beginning of our summer) and she had grown back new tail feathers - except now they're gone !!
As for increasing protein , they get fed a complete layers mix - or so the packet says - along with the usual household scraps and figs/olives that my son pulls off the trees for them , to up the protein , do you think it would be sufficient to hard boil them some eggs / feed them some mince to get it back up ??
We have one geriatric Araucana hen (shes 4/5 so maybe not ancient , but definitely past her prime and feeling her age) who is bottom of the pile when it comes to the hen hierachy. While she rarely lays (hubby wants to put her in the pot , but im rather attached to the old girl) when she does her eggs have a very very soft shell , and sometimes no shell at all , just a sort of rubbery sack encompassing the yolk/white - is there anything I can do to help harden her shells?? She has access to oystershell grit but dosent appear to be very interested in it.
No feathers on the outside of the coop , but we don't have Raccoons in NZ , we do get the odd stoat though, our cats are pretty good for killing them!