Is this a particular type of chicken or just a mixed breed

[Tinydinomomma]

In this picture there is a hen in the back near the chicken door with a red head and a grey backside. Is this a particular type of chicken or just a mix breed? I have like 3 of them like this. Thanks.

 

[Ecarroll]

In this picture there is a hen in the back near the chicken door with a red head and a grey backside. Is this a particular type of chicken or just a mix breed? I have like 3 of them like this. Thanks.

Where did they come from?

 

[Tinydinomomma]

Where did they come from?

I got them earlier this year from a guy up the road from where I live who bought fertile eggs and hatched them off.

 

[JedJackson]

It's a mix. I'm guessing blue Orpington x Rhode Island red, but who knows for sure.