The female (in the forefront) comes and goes quite a bit. The male (in the background) flies around outside keeping close watch for them. And we have noticed that when she is out, he will sit on the perch and look in, sometimes until she comes back. Why?
There are two eggs that we can see. And once they hatch and leave the nest, the mother may lay another bunch! And the other box in the yard? She builds a nest in that one too, to keep out any rivals. Amazing.