Sexing 6 Week Old RIR and Blacktail Chicks

[OpheliaM]

Could anyone help me out with sexing these chicks? Lighter one I think is a blacktail and darker one is RIR. I won't put what I think their genders are so I don't influence anyone! Any suggestions appreciated!

 

[pozees2]

If it's just the two birds I think the lighter one looks girlish right now and the darker one looks boyish but could be fast maturing bird. How old are they? What do you mean by a Blacktail? Where did you get them?

 

[OpheliaM]

If it's just the two birds I think the lighter one looks girlish right now and the darker one looks boyish but could be fast maturing bird. How old are they? What do you mean by a Blacktail? Where did you get them?

One Columbian Blacktail (cross between Sussex and RIR) and one Rhode Island Red. The pictures are the same 2 chicks just from different perspectives. They are just under six weeks. We incubated the eggs and they hatched at the end of May.