Yes, definately the bowing and cooing can be a big give away of a male, plus the hip bones. Also a good tip I got previously was to place the pigeon in question alone with a mirror, if they bow and coo at the mirror they are male, if not they are female, again this is not 100% certainty but will give you a good indication. It is quite difficult sometimes to tell, but following the above should help you have a rough idea