for me its around 6 to 7 weeks when i could tell forsure the sex of a JG but im pretty new to these guys and have only raised 17 babies but at around 7 weeks the roos will start to develop little wattles and their combs will start to out grow the pullets and also the color of the comb and...
We used to crow hunt several years ago, the call we used was a electronic call that had crows hollering and owls hooting.. more times than not a Hawk would come in to investigate what the ruckuses was all about..i think those calls you are talking about are made to deter rodents and smaller...