Yeah I totally see it it's kind of like the males beaks head upwards in the centre and the females turn slightly downwards. It's very slight. But now that I see it I'm going to see if it's true for these guys and my newest batch when they finally hatch.
Here you go. Looking right at you lol the two on the front have a bit of a darker tip on their beak as well.
Those black beans! thats what I should have looked at.My teenagers <3 the one in the middle has started making a quacking sound but I thought I had two boys and a girl.. so he may just be confused.