I've found the crowing happens (4 adult roos before) when they're released from the coop for breakfast (some inside when waking up, not all night): come out, look about, crow "all well", move about, grab a bite or 2, crow again after checking another area.
When an alert warning goes out, crowing occurs when whatever set them off has cleared. This is where I've heard 2 different calls for birds flying around. One call is very similar to the "MOOOMMM! The neighbor cat is visiting, come remove it! It's not afraid of us!" I hear this one for any bird Robin sized or larger, including crows and magpies. The other call is much more rawkus(sp?) And seems to mean DANGER IN THE SKIES. It's used for any hawk (little merlins up to red-tailed) and includes turkey buzzards and any other large bird flying through if the bird is an unknown. The first call results in heads popping up and all eyeing the intruder, all poised to run for cover. The 2nd results in instant flash freeze with NO ONE moving until "all clear" is called. When littles are about, the "DONT MOVE" is repeated periodically but in much quieter tones. "All clear" is again crowing.
Sentinel duty is also when I hear it. Periodically the sentinel roo will crow, I think simply to reassure the ladies that he's seen nothing to worry about, carry on with what they're doing.
I don't hear much crowing around bedtime. Instead I hear "shut up and go to bed" chooka-chooka-chooka (when there's some disputes about where to sleep) or purring when most are settled (maybe equivalent of singing a lullaby?)
