Relationships of Avian Cecal lengths to food habits, taxonomic position, and intestinal lengths
Body mass, intestinal lengths, and the occurrence and relative size of ceca from 154 species of birds representing 21 orders and a diversity of food habits were compared. Well-developed ceca occur in the Anseriformes, Galliformes, Gruiformes, Cuculiformes, Strigiformes, Caprimulgiformes, and Trogoniformes. The presence of well-developed ceca is less consistent in other orders and appears to be related to diet; herbivorous species whose diets contain large amounts of cellulose have well-developed ceca, whereas species having diets rich in soluble sugars and proteins tend to have poorly-developed or no ceca. We postulate that the relatively well-developed ceca in some non-herbivorous birds are associated with conservation of critical resources such as water and nitrogen.
DeGolier, Teresa F.; Mahoney, Sheila A.; and Duke, Gary E., "Relationships of Avian Cecal lengths to food habits, taxonomic position, and intestinal lengths" (1999). Biological Sciences Faculty Publications. 19.