I'm just curious if since one is larger, the wing stripes are different, and has less yellow on top of the head, could that mean that one is a male???
Anyone know or are these too small to tell?
Shipping can be rough on them. I (and many others) this year have had a lot of losses from Ideal Poultry birds - my reasoning for asking. Realistically, most commercial hatcheries & the USPS don't really care about the well being of these birds. Not preaching - I order from them also occasionally, just noting. As far as your birds in particular - it could be any number of things really - illness, nutrition, dehydration, so on and so forth. I would try some electrolytes or sugar water to see if it gives them a boost. The chick that's 'fluffed up' in the photo above doesn't look great...
That she's drinking on her own is good. Dehydration is terrible for chicks, and like you're doing you can load her up on electrolytes and vitamins via drink to help her out. Running around is a good sign as well. I just had a chick hatch from a saddle shaped air cell that needed help hatching because of a funky position. Like yours, she had to get splints to walk and such - she's up and running but still in that stage as if Im not sure she's going to make it - Actually surprised to see her alive when I tilt back the ecoglow in the brooder (always expecting a corpse). Chickens can be frustrating in that it's easy to them to fall sick and/or expire - being 3 weeks old adds some durability. Are they on medicated feed (or vaccinated for coccidiosis at hatchery)? Still in the brooder or are they outside?
Did the Silkies come from the same hatchery and in the same order?