Also, when you cut the head off it severs the spinal column which makes them harder to pluck. After bleeding for a minute they say to stick a small blade in the mouth of the bird and cut the back of the brain to release the feathers better. I wish I could get a chicken to smoke a cigarrette with a blind fold on. Especially if it was a marans. Need to get better with graphic design.One school of thought on using an axe or clippers to sever the head is that you are crushing blood vessels and tissue so you may not get as good of a "bleed out" as if you slice the jugular with a very sharp blade.
I have done both (sample size 10 birds) and found that the bird acted much calmer bleeding from the cut jugular. It was also easier to control the mess and there was less blood left in the body.
Hope that wasn't too graphic.
I appreciated your warnings at the end about the smell and feel while butchering. Really nice job.