Feather growth and telling chicks apart, questions at 3 weeks

So the chicks will be 3 weeks old on Wednesday. The brooder has been moved to the coop since temps at night aren't so cold any more. The past few days they get to run around in the coop most of the day. They are having lots of fun and growing very fast.

My 5 ISA Browns have very different rates of feather growth. They are supposed to all be female (although I know mistakes happen). Do you think there are issues with any of them. The two with the fewest feathers seems to want to "nap" more than the others. Here is one of those, with a few other pics below for comparison.





Also, when the chicks were really small I could always tell all ten apart. You would think that with the varying stages of feather growth that I could still do that but they change so much every day I am having trouble telling which yellow chick is which, and that makes it hard to name them. My brown unknown breed chicks are all distinctive enough even as they change to have names. Will the yellow ones be easier to tell apart when they are all fully feathered?

Here are a few more pics including some of the other chicks just for fun.

I band my chicks with zipties. This one has two bands as a reminder that she's a keeper not a for-sale.




Just remember to change the bands regularly as they grow.

Thanks.

Anyone else with comments or suggestions? Especially about the two with slower feather growth.

TX Chick Noob said:

Thanks.

Anyone else with comments or suggestions? Especially about the two with slower feather growth.

Click to expand...

Isa browns are sex links which means it's almost impossible to get the gender wrong. However depend on the parents of the individual chicks, they could feather in faster or slower according their genetics.

Well I guess this one didn't mind too much getting a leg band....

TX Chick Noob said:

the two with slower feather growth.

Click to expand...

There is a gene that controls how fast chickens grow their feathers.
Some breeds are all slow-feathering.
Many breeds are all fast-feathering.
And some have a mix of both types.

The fast/slow feathering can be used to sex chicks, if someone plans the parent matings properly. But the next generation gets random feathering speeds. So the hatchery might be using feather-sexing for the parent stock, and color-sexing for the chicks they sell to you. That would cause the color-sexable chicks to have a random set of feathering speeds.