I have seen young cockerels doing their practice bluffing/fighting very early. In fact, last night I saw two of my 11-day old chicks puffing up their chests at each other--just for a moment--and then turning and walking away. Sometimes they make the motions of crowing really young, too, even though no sound comes out. Boys......
*** I should probably add that these are only \"tips\" and not definite rules. I raise all of my chicks to adults unless they have a physical problem, so I only use these observations for entertainment and not any culling purposes.