I received a shipment a month ago today (arrived 12/3/14) of straight run RIRs. By now they are all sporting most of their feathers. But they are still peeping. It seems that there are some characteristics that go together. One Type: larger (proto) comb, shorter tail feathers, more aggressive at the feeder Other Type: smaller (proto) comb, longer tail feathers, less aggressive at the feeder These characteristics are consistent, i.e. a chick that has one has all three. My questions are these: 1) Are these reliable predictors of sex and 2) which is which? I'm assuming the more aggressive feeding would be the males, but want some confirmation if I'm not on a "wild goose" chase here.