Update: Cockerel started going after a second 18-month old layer and bloodied up her comb pretty good. Was def not a mating issue. She is a very sweet, very productive lavender orpington. I watched him chase her around and around and attack several times. He was still going after the Easter...
I have 12 chickens--6 1 1/2 yo layers; 5- 6 month old pullets and an "accidental" 6 month old splash ameracauna cockerel. He is human friendly, and generally flock friendly. Totally mixed flocked. All laying except several layers are in molt.
Coop is 12x9 with a suspended roof and ceiling...