Pullets or Roos?

[AUFan]

Can you tell by their feathering?? I got 26 straight run Delawares(they hatched on the 28th so they are a week old) and then my one silver laced polish. About 15 of them have lots of wing feathers and their tail feathers are starting to come in. The other 10 have short stubby feathers on their wings and no tail feathers. My lone polish has lots of wing feathers too....SO my question is could I tell which were pullets and which were roos by their feathering? And if so which is which? THANKS!

 

[silkiechicken]

Some birds are bred for fast feathering females and slow feathering males, however, if you don't know that as a fact, looking at feather growth will be a 50/50 shot in the dark.