I've been thinking about how the book didn't really address the piling up issue and wondered if over time as chicks have been bred and raised under different conditions they are less able to cope--sort of what I've heard about commercial turkey breeds not knowing enough to come in out of the rain or some of the meat chicks that get too heavy too fast for their legs to hold them up. Just wondering as I try to make it work less like a factory.
I think you may be right about commercial breeds losing their survival instincts. I've only raised heritage breeds of chickens: Speckled Sussex, Dominiques, Cuckoo Marans and Welsummers. The Sussex were my favourites--even the rooster was a good boy--and they certainly seemed to have all their free-ranging skills intact. We are fortunate in living just down the road from a breeder of heritage birds. Every bird I have bought has come from there.