This afternoon when I went into the coop to collect eggs and feed the chickens, I discovered Mary-a one year old Ameraucana, dead in the coop. She was lying under the roosts like she had just dropped dead in the night. My birds have outdoor and shade access as well as fresh water all day. They stay in the run in the morning and then free range til evening. I had not noticed Mary wasn't around but she may never have made it out of the coop this morning. There was no sign of injury or disease that I could see. This has happened one time previously a few months ago to one of my RIRs. Does anyone have any ideas?