A couple of people have emailed me to say that males have no role in nest building or anything to do with raising the young so my assumptions were apparently purely speculation. One of them stated that a male would mate with any female that is willing. But also that there is no pairing up, which certainly doesn't seem to correspond with what I appear to be witnessing. My male is very tolerant of only one of the females that I have at my feeder. However, there could be alternative reasons for that.

Rod Gilbert