This article provides many reasons for choosing heritage breeds instead of industrial production breeds for one's flock, such as foraging ability, disease resistance, broodiness (which some see as a positive thing, while others view it as a negative trait), appearance, predator awareness, and productive longevity. Most of these traits are valuable in a free ranging flock, but their usefulness to penned birds is less obvious, and heritage breeds do not always fare well in confinement, so some discussion of the environment in which the flock is to be kept would be appropriate.
