Six weeks ago I got a new shipment of day-olds. I ordered five. I got six. Sorting mix-up at the hatchery, they said. So I got a free chick by mistake, no idea if it had been sexed or was straight run, no idea if it was male or female. After searching online for photos similar to my mystery chick, I decided it's probably a Partridge Rock. My daughter named this chick Elmo. (We also have Abby, Zoe, Oscar, Grover, and Chloe in this batch.)
Now the babies are six weeks old, and the five I ordered (sexed females) all appear to be developing about the same. Elmo is bigger than all the other babies, has huge feet and legs compared to the others, and is feathering out differently. There are also tiny pinkish wattles beginning to come in, and the comb is bigger and a little pinkish too. No crowing attempts yet, but six weeks is young for that anyway.
I've suspected that Elmo was a boy since about a week old, but is six weeks old enough to make that determination for sure?
With everyone else:
With Abby the Buttercup (pardon the headlessness. Elmo stretched up tall right as my shutter clicked!):