Method of marking/ID'ing chickens

[Savitar]

I have 4 Blue Ameraucaunas, about 10 weeks old. At least one has started crowing, but they all look identical to my eye. Is there a safe method to identify each one so, when one crows, I know it's time to find them a home. They all have the same feathering, and such tiny combs. Possibly one of them has a slightly lighter color comb, but they are all red/pinkish at this stage. No saddle feathers or any other male identifying feathering yet, but they seem pretty full feathered. Based on temperament, I'm afraid I got all roosters. This is in addition to 3 out of 4 of my Salmon Faverolles turning out to be roosters, and likely 3/6 of my Appenzeller Spitzhaubens being male. Not winning the lottery this year!

I post pics soon, but in the meantime, wondered if there was something I could place on a leg that would help me ID the crowing one sooner.

 

[DobieLover]

something I could place on a leg

Yes. A leg band.

I just banded my Ameraucanas last night with these.

 

[Savitar]

Thanks, looks like I'll be ordering some!