My chicks are 5.5 weeks old (straight-run) and we're not 100% sure on boys vs. girls yet. This is our first time having chickens and this board has been a HUGE help so far. On some of the questionable ones, can I assume they're boys at this point if they square up against another boy chick, fluff out their neck feathers, stare them down and start chest-bumping? Or is this not necessarily indicative of a boy? I would HATE to give away any of my hens by accident...especially since I paid more for the Black Copper Marans, Lavender Orpingtons, etc. and have worked so hard at keeping them happy and healthy in the past 5 weeks!! Sarah
Behavior at this point is not really a reliable indication of gender, no. I would not re-home anyone at this point that I was not 100% certain was a cockerel (massive red comb/wattle development). There is nothing to lose by keeping them to the point where you are certain (crowing, development of sex feathers, etc) - and everything to lose by re-homing one too soon.