I know this question is so old..... but my curiosity is getting the best of me. I have 4 red star chicks that are almost 4 weeks old. I bought them with someone who told me that they should be female. Anyhow, 3 of the chicks are all growing wings and tails and feathering at the same rate, one is much slower in that sense. This one in particular was also the largest chick of all 4 when we received them at days old. Is this a sign of a rooster? Thanks!