Parlor roller pair is setting third time on eggs. Still nulliparous. Why?

[bantyshanty]

Okay, I don't know if that term applies to squeakerless pigeons, but they haven't had any luck brooding.

This is my only pair. They're about 9 months old now. Had them since 3 months. They set 2 eggs in April, gave up after 3 weeks, and I candled. Nothing in the eggs. Clear. No development.
They did the same thing in May. Same result. This time, they set 3 eggs, and during our few cool days this month, each bird was on eggs. SInce the hot spell came, it's just the male days, the female at night. They are on a largely millet diet, mixed red & white, with some dried greens, kelp, fruit bits, other seeds, etc. They have a 5x5x8' aviary to themselves in a detatched porch, with a nice 3 sf nesting area. They take a water w/ vinegar bath almost every day. They roll well & stroll about between attempts.

Is the male just not doing his job right? Does this happen to parlor rollers? I had someone ask me if he's male. He definitely is male. Suggestions? I'd like them to have a reason to stay around when I roll them, as we have no grass on or property, just acres of forest to get lost in if they chose.

 

[Narragansett]

It is extremely rare for pigeons to lay more than two eggs. What is much more common is for owners to insist that they have the correct sex, when they don't. There are several other possible causes of infertility, but before wasting a lot of keystrokes, I'd like to know what makes you so certain that you have a male and a female.

 

[bantyshanty]

I think that I have a pair because, first, I was sold them as a pair by a man who's bred rollers for a long time. Second, the bird in question is darker and has lots of iridescent spots on his/her breast & sides. Third, I have seen "him" stand on top of the hen as f to mate, although I haven't actually seen them mate. I know this isn't very conclusive. Here is a picture of them. Unfortunately, the bird in question will not leave the eggs during daylight hours, and only switches with the partner at twilight, when I can't get a clearer shot. The "male" is dark chocolate. The female s light chocolate. Does this help?
Boy on left? See iridescence on head? Girl on right.

 

[bantyshanty]

The "boy" covers three eggs while his/her mate is gone, then gives the last one back when she is done feeding & preening.

 

[larrylofts]

you have two hens sorry but the breeder made a mistake good thing is better to have extra hens than males and easier to get extra males color size has no indication of sex

 

[bantyshanty]

Okay, thanks, larrylofts, I was going with the impression all this time they were a pair. As a still newbie, then, how can one determine sex of rollers?