Steve Wilcox was the lucky person who had a pair of Western Bluebirds build a nest in his birdhouse. Here are the parents, with the male on the left.
Western Bluebirds are thrushes. When they aren't breeding they like to travel in flocks, being very social birds! To hear their calls, here is a link to the Cornell Lab of Ornithology: https://www.allaboutbirds.org/guide/Western_Bluebird/sounds
Thanks to Steve for allowing me to share his photos with you here.