Hello chick experts! Always love to hear from you. Thought I would post my observations this year on determining the sex of my 10 Speckled Sussex. I got them from Ideal. Supposed to be pullets, but I know sexing is difficult. I wanted to explain what I am seeing and why I am nearly certain I have 3 Roos. Here is what I see at 1 week old. 1) In the ones I see as pullets, their bodies are more neatly shaped with smooth lines from shoulder to tail. 2) Pullets with full wrapping wings to the back. Wings appear to have the longer feathers toward the top when folded. Wing tips go all the way to their tails. When out-stretched the feathers are nearly even. 3) Pullets are getting tail feathers straight out the back end. 4) Pullets peep softly and chatter, often in one tone. 5) Pullets have a dark brown dorsal stripe that starts on the top of the head, is connected down the neck to the back, and either wide, crooked, or even very narrow. 6) Now for the Roos. I see a stocky body like a football player. Broader at the shoulders of the wing (for lack of a better description..haha). 7) Wings are much shorter when folded with the longest wing tip appearing at the bottom, which clearly sticks out. They do not extend to the tail. The outermost (shorter) wing feathers are very short. The left wing from side view is in the shape of an "L". When outstretched, the long feathers do not lay even with the upper feathers of the wing. It is very clear! No mistaking it. 8) No tail feathers. More of a fuzzy rump. 9) Back of the head is much fuller and fluffier than the pullets. 10) The dark brown dorsal marking is different. All three Roos (or what I think are Roos) have a brown spot on the top of the head. This spot is disconnected at the neck and starts again down the back. 11) All three Roos have a distinctive loud chirp, and it is not one tone. It is usually a loud chirp, then chirp-chirp-chirp. One of these boys even stands up tall and arches his neck when he chirps. I do not see pullets doing that. 12) The combs on the Roos do look slightly bigger, but very hard to tell this early. 13) Body color on the 3 Roos is generally lighter than all the others (although on this breed I think pullets can be lighter, too). This is only my second batch of SS babies. I had only 4 pullets last year with other breeds. However last year all 4 looked exactly like the pullets this year, and definitely not like the roos. I'm no expert. But, I will be surprised if I'm wrong. Anyone else have any ideas? I would enjoy any feedback. My biggest characteristic of all has to be those wing feathers, as they are drastically different in how they are placed. If this is a true tell-tale sign, then I will feel quite confident telling the sex of this breed at 1 week old! Thanks everyone! I hope this is helpful to someone else. This is a beautiful breed.