Sexing hecks finches, your methods?

[finchbob]

I recently bought 13 hecks finches, unsexed. I need to figure out their sexes, and that's proving difficult. The information I have is that the males have a larger bib. Not a great help since depending on the position they are in the bib may sometimes seem very wide or very thin.

[dfcauley]

I think that if you take them one at a time and put them in a cage in another room it won't be long before the males sing. Mine sings ALL the time.

I did that today with an owl and it wasn't long before he was singing because he could hear the other birds.

[lovemyfinch]

They don't even need to be separated, I double banded one of mine today as soon as I caught him singing.