FINCHforum

I came across this while looking at the various society finch mutations:
Sexing Bengalese 2

Of course singing is the best method, but has anyone tried this and found it reliable?

Never tried this before. I always just wait to see who sings and who doesnt.

Icearstorm

Nope.
I always go by singing.

I also go by under the beak/bill.The male is a C curve and female in shape of a V

But also Male has a bigger shaped beak overall.

You can also sex them by the position of the eye relative to the side of the beak, but it is not 100% reliable. When I see a really pretty bird, I instinctively know that it is a cock bird, but by selective breeding, I have bred some very good looking hens.

Never tried i use the song way. In the next clutch i'll try the beak way

A few people identified my white hen, Pyewacket, from photos using beak/head shape as being male.

She is most definitely laying eggs now.

To be fair, that was from not very good photos posted on the internet and was probably strongly influenced by my report that she was doing a sort of abbreviated "song" (but not really the dance part and definitely she never went pair-shaped).

Looking at my birds right now, knowing one is female and one is male (they are currently sitting on 5 hopefully dud eggs and Bambi DEFINITELY does the full mating ritual including going pear shaped) I cannot see any difference between them as far as head shape, beak shape, where the eyes are, or how "attractive" they are. They're all attractive to me, even poor Bambi and his permanently plucked tail feathers.

I'm sticking with song-and-dance, or actual genetic testing. Its only about $15 or $20, though the blood collection method is rather hair-raising IMNSHO.

Finch farm marks that way way up - $100 for DNA testing.

EDIT: Unintentional pun there. Pear shaped, not pair shaped, LOL! Though he has to go pear-shaped to pair with Pyewacket, LOL even more!

Sojourner
I also have a society finch that may have been identified as male had it not been for the egg-laying. I call her Finch the Finch (most of my pets have weird names), and she kind of acts like a male. As I often see with my male finches, she will fly right up to another female immediately after that female was mating, and proceed to mount her and flap around as a male does when copulating. It's as if she thinks she's competing with the male for her share of baby-making. But I saw her lay an egg, so now I can be sure she's female (unless she's a chimera, but that is extremely unlikely).