Tf. Degolier et al., Relationships of avian cecal lengths to food habits, taxonomic position, and intestinal lengths, CONDOR, 101(3), 1999, pp. 622-634
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 h
abits; were compared. Well-developed ceca occur in the Anseriformes, Gallif
ormes, Gruiformes, Cuculiformes, Strigiformes, Caprimulgiformes, and Trogon
iformes. The presence of well-developed ceca is less consistent in other or
ders and appears to be related to diet; herbivorous species whose diets con
tain large amounts of cellulose have well-developed ceca, whereas species h
aving diets rich in soluble sugars and proteins tend to have poorly-develop
ed or no ceca. We postulate that the relatively well-developed ceca in some
non-herbivorous birds are associated with conservation of critical resourc
es such as water and nitrogen.