Australorp chick question

[iam4hymn]

I have two 3 week old Australorp chicks that were hatched on October 13. One is growing/feathering quite well (chick 1), the other one has tiny wing feathers and most of its down(chick 2). She is the tiniest one of the group but is eating and drinking just fine. The rest of the chicks I got are growing and feathering out nicely, but this little chick just looks like a larger newborn. Any particular reason she is lagging behind?

Chick 1

Chick 2 with nubs for wings!

 

[tj74roberts]

I'm guessing that its a cockerel. They feather slower than pullets

 

[shortgrass]

Some are just smaller; might have been a smaller egg, different genetics, the runt, etc.

Cockerels can be slower to feather, but it would be easier to look for cockerel by comb development at this point.