Beak colour in tibetan coturnix

[nikirushka]

Just wondering if anyone's birds follow the theory. On the old coturnix colours thread, there's a theory mentioned that male tibetans have light coloured beaks, and females dark.

I only have two adults, one of each, and they do follow it. Both my tibetan chicks have dark beak tips so I'm really hoping it's true - has anyone else noticed the same thing?