Pretty sure it’s a pecking order thing.

[Crazy Horse chickens]

This gray hen ( I’m pretty sure) nothing about her points to rooster. Is 14 weeks tomorrow, she is mounting her smaller flock mates. They have been raised together the behavior started last week. Is she simply asserting her dominance?

 

[oldhenlikesdogs]

That look like a little cockeral. I've never seen an immature female bird mount another.

 

[azygous]

It's most likely what you've concluded - a pecking order thing. But there is a rare possibility she has a damaged ovary. When that happens, androgen hormones begin to be secreted, and that will cause behavior to become more aggressive.

If she never lays eggs, this will likely be the reason. On the other hand, she may be a he. Look at the tail feathers and see if you see any curved sickle feathers beginning to poke out. That would be undeniable evidence it's a cockerel, albeit a slow to mature one.

 

[Crazy Horse chickens]

I’ll keep an eye out this pic was taken a few weeks ago. She has no saddle feathers has no pointed tail feathers her tail fans out vs. standing up straight. Her comb is just now starting to turn red. My other for sure rooster has had a red comb since he was six weeks old.

 

[Crazy Horse chickens]

This is a picture of gray today. She is the one mounting.

 

[oldhenlikesdogs]

This is a picture of gray today. She is the one mounting.

That's a cockeral. You can post in the what breed and gender forum to get more opinions.

 

[Crazy Horse chickens]

Threw reading investigations and other opinions I have concluded that this is a Dominique roo. He is not a barred rock, Like I was originally thinking.

 

[Crazy Horse chickens]

And he is very good at doing him roostery things.