Can A rooster tell if A hen is fertile?

[Mattl12]

1 of my roosters is finally acting like A still mostly failed rooster after 5 months and I noticed him mounting the smallest hen. Said hen has very little waddles and virtually no comb, I cannot verify she is laying nor does she "squat" like the other 2 I know are laying. Does A rooster know? Put another way will A rooster mount an infertile hen?

 

[IvysAnimals]

I don't think they can really tell...And unless you know for 100% they're infertile, they can really be infertile and / or not lay eggs.

 

[nuthatched]

They typically don't try to mount an unsubmissive Pullet but they will if they're particularly hormonal

 

[Mattl12]

They typically don't try to mount an unsubmissive Pullet but they will if they're particularly hormonal

Yet to see either of the roos try to mount the alpha hen or her slightly smaller "companion" for lack of A better word. My 10 week old Bresse roo tried .......... That didn't go his way. Funny as hell though to see he thinks that highly of himself.

 

[Wyorp Rock]

1 of my roosters is finally acting like A still mostly failed rooster after 5 months and I noticed him mounting the smallest hen. Said hen has very little waddles and virtually no comb, I cannot verify she is laying nor does she "squat" like the other 2 I know are laying. Does A rooster know? Put another way will A rooster mount an infertile hen?

Is this Rooster only 5 months? Then he's a cockerel and he will try to pretty much mate anything. So yes...a cockerel will mount a pullet, he will bully a pullet a lot of times.
If he's being a major pest, then ensure you have plenty of space, some places for the hens and pullets to get away from him. Or you could separate him for periods of time to give the girls a break....
Pullets at 5 months are generally not too keen on mating. Older hens (more than 1yr old) are not always that keen on a cockerel mating them.

A Rooster (more than a year old) that is mature *should* take more note of who is ready to mate (in lay) and who isn't, doesn't always work 100% of the time. For the most part my Brood Cocks won't mate pullets that are not in lay. Oh, they will flirt with them, but they won't mate them. Pretty much the same with hens that are molting, flirt but no dice.