Can you tell chick gender by tail feather development?

[therichhens]

We have a pair of Buff Brahma chicks (3 weeks old) and a pair of Speckled Sussex (two weeks old) and I'm wondering if the tail feather development is any way to tell the genders apart? In each pair, one chick has developed tail feathers dramatically faster than its counterpart. These were straight run and we've only ever bought sexed pullets before.

Here they are, the Brahmas first then the Sussex:





I'd love to hear your thoughts!

 

[Fred's Hens]

Many times, with some breeds, yes.

When this "works", the no tail is a cockerel and the long tail is a pullet. However, do not bet the farm on this. It is merely an indicator, not a certainty.