Why does he do this?

[Chickassan]

Yes put him in. He will be very thankful, they are not very smart at that age. You'll be doing him a solid.

 

[pennyJo1960]

My boys all go in the ameracauna rooster helps to raise the young always roosting with them but mine have tables made of pallets they roost on

 

[Chickassan]

My roo didn't roost at all for about 6 months, he slept on the coop floor. Same kind as yours Op. Your other question is he sexually mature. He is physically sexually mature but not mentally. He could sire chicks now, yes he could but he's probably still working up his courage with the ladies.

 

[chickengeorgeto]

Every night my hens go inside the coop but my rooster never does. He just lays on top of the run. Why doesn’t he go in with [them]him? .... he is about 5 months old, is he sexually mature at this age?

The hens are all under one year old. There is plenty of roosting space. When he was in the introduction coop/run he would go inside on his own.

He is skittish around the girls but they don’t pick on him. He really loves the Cochin and one of my Isa Browns.

In my mind being sexually mature means that he can father chicks. At 5 months old this is not a given. Especially healthy vigorous chicks. Also he is likely not the boss of the flock and this is a prerequisite for a cockerel to join the flock. A alpha hen will dominate a beta or omega cockerel and he will not venture into the lions den of a coop full of hens.

Don't take my word for it, perhaps someone else will speak up about the violence that goes on among a flock of chickens at bed time. I highly recommend that everyone reading this gets a comfortable chair and spend an hour watching their chickens getting ready for bedtime, it will open your eyes.

Omega cockerels very often have favorite hens. This is mostly true because only one or two hens will even give a cockerel the time of day.

 

[Trux]

The thing is he is outside of the run. On top of the coop

You should at least put him in the run or you may end up with no cockerel in the morning

 

[janiedoe]

The thing is he is outside of the run. On top of the coop

Yes. I understand. Our coop is completely enclosed within a covered run. I only worry about mine when the weather is extreme.
Is there an area inside your run near the door where you could place a tall t-post? (Maybe a tall mailbox post) Something where he could be up high and still be protected in the run. I believe he is just doing what he instinctively does and finding a high point to watch over his flock.
I have two young roosters right now and they both sleep on the roof. One occasionally goes inside but never stays. He has such large feet that he seems awkward on the regular roosts. He won't use the 2x4 roosts either though, he just goes back out to roost up top. If you put yours inside every night he may eventually start going in on his own. Good luck.

 

[Cheyenne97]

I put him in every night. I’m considering opening up another coop for him and his two favorite girls. He’s 5 months old and still doesn’t crow. (Knock on wood) I’m very pleased