I agree with that completely!! We've had -18 temps and I have not heated, mostly because I want my birds to be hardy... if they don't survive the cold, then I don't want them.. Of course, they have a coop that is protected from the wind and such, but no extra heat... Interestingly, I've only lost one chicken this winter, a hatchery RIR pullet.... survival of the fittest I guess
While I completely agree with survival of the fitest...I have no choice but to use a heat source for -40 below here! Its only a few days each winter...and mostly -30 thats an extreme weather condition and for that they need heat...when it gets above -15 -10 heaters go off...