The first time I saw this female bluebird sunbathing I could not bring myself to photographer her because I thought she was dying. I thought that all was lost... This second time I googled the behavior and discovered many birds sun themselves in this manner and for a variety of reasons. This female is sunning in full sun during the heat of the day and preened herself immediately after.
BluebirdIowaHarold R Spencer Bluebird TrailSunbathing