Dark brahma chick growth/development question

[dreamofwinter]

Hi all!
Among the day-old chicks I ordered this year, I got 4 straight run Dark Brahmas. They are all 4 weeks old now. Three are well feathered and, based on what I've read here, two of them are almost certainly are pullets. One may be a roo, as her wing feathers are much darker/more solid than the other two.

It's the fourth one - almost certainly a roo as his few wing feathers are coming in almost solid black - that I'm worried about. Compared to all my other chicks, he is quite small. He's always been a little off - he would hide under the heating plate and yell while everyone else was out playing and eating. Last night I had a good look at him and realized that aside from his primaries, his wings have no feathers yet; and he's only just sprouted the beginnings of a tail. Poor little naked guy! All the other chicks can fly around my mudroom and he's stuck on the ground.

Is this normal for a brahma roo - slow feather growth and a little dorky? Or should I be worried there's something else going on with him?

 

[dreamofwinter]

For comparison, some photos. This is one of the brahma pullets:

This is Brad:

Here they are next to each other (ignore that huge Barred Rock in the background... same age, but a big chonky girl!)

Same hatch date. I think he'll catch up eventually but in the meantime I hope the ladies let him snuggle up when they move outside in a couple weeks!

 

[dreamofwinter]

Following up on my post about my Dark Brahma roo's weird feather development. He's 13 weeks old now and looks totally normal except for a few primaries that grew in upside down:

"normal" side:

He's not quite as broad-breasted as our other DB roo, but seems happy and healthy in every way. Hoping that when he next molts those bad primaries they'll grow in with normal aligment.
Has anyone seen this with their own flock? Any idea what caused it? Interestingly, his feathers were horrible and ugly till we moved them outside around 6 weeks, at which point he became handsome almost overnight. Maybe a deficiency that living on grass helped fix?