I've been away from BYC for a while now, only just logged back on and noticed the RIR and Black Australorp photos you added to my collection (here: http://www.backyardchickens.com/a/rirs-and-black-australorps). Cool!! I didn't even know if it was possible for another member to add photos to this gallery, so great to realise that you can.
Am I right in thinking that all apart from the first Australorp turned out to be pullets? With the benefit of hindsight, would you be able to arrange the photos by individual chick, so that they chronicled its development up until the time that gender was obvious?