I've got a year+ Speckled Sussex doing the same thing. Her sister was killed in the coop by a raccoon over the weekend, and somehow Lucky Penny survived. Now she has 2 new sex-link pullets (still cowering in the dog kennel) and she's been crowing the past 2 mornings. I take it as a sign that there's a predator near, and keep them in the (now) secure coop for the day.
