Question: does significant human intervention during the setting, incubation, and raising of a brood negate its 'naturalness'?
How natural is it, really, if the human keeper controls a lot of the parameters? Or is 'natural' here just standing for 'using a broody rather than an incubator'?
I believe you will get many different answers to this.
Since my chickens are domesticated I consider "natural" to mean minimal intervention by me.
My birds are always protected by fencing. Broodies are given a private space from incubation until the chicks are a few weeks old. When the hen seems ready to leave the chicks on their own, this is when they mix with the flock.
This is as natural as it gets for me.
We are in a rural area with coyote, bobcat, red fox, gray fox (these climb trees), raccoon, weasels, mink, skunk, very large black snakes, couple types of hawks, eagles, vultures and occasionally black bear.
There are lots of chicken keepers in my area. Most that free range loose many birds each year and just plan on replacing often. I just can't do this. So I give my birds a large run and don't overstock so they have lots of room. I give them veggies from my garden since they can't free range. This is the best I can do for them.