Rooster or a Hen?

We went for a visit to Chris and Sara Guerre's farm this weekend and visited the, now almost 4 week old, chicks.  They are looking spectacular and gangly with all their new feathers and gigantic feet :)  I have to say, the beaks are the most impressive to me.

They are staying warm in a special out building that has been insulated and heated with a space heater.  In just a few more weeks they will be ready to move to the "big hen" coop.  It is fun trying to guess which ones are going to be roosters and which hens. We thought we might have heard a tiny crow while we were sitting with them in their brooder.  But it was hard to think that is even possible!  With some breeds, you can tell right away by the color of the chick what gender they are.  With these Ameracaunas it is a little trickier and mainly a waiting game.  Some of chicks are already growing combs, are they the roosters?!