Bohaiornithidae of sexual dimorphism, with the feathers being used by male members of a species for courtship display. A subadult specimen of an indeterminate bohaiornithid described in 2017 preserved feathers on various parts of the head and body which were analyzed and determined to have been iridescent in life. A referred adult specimen of "Bohaiornis" was preserved with a several rocks concentrated in the stomach region. Rocks in the stomach of birds and other animals are often believed to be gastroliths swallowed to assist in the digestion of plant material. However, the rocks apparently swallowed by this specimen are much larger,
Digestion size of the meal, and the process of digestion normally takes between 24 and 72 hours. Digestion begins in the mouth with the secretion of saliva and its digestive enzymes. Food is formed into a bolus by the mechanical mastication and swallowed into the esophagus from where it enters the stomach through the action of peristalsis. Gastric juice contains hydrochloric acid and pepsin which would damage the walls of the stomach and mucus is secreted for protection. In the stomach further release of enzymes break down the food further and this is combined with the churning action of the stomach.