As I sat at my desk I watched a covy of California quail (Callipepla californica) scratching and feeding outside of the window, plump and healthy in mid-winter. Why are these quail doing so well while other birds appear stressed? Perhaps it is due in part to the protozoans that aid the quail with digestion?
California quail are mainly seed eaters but also eat insects and other vegetation. Particularly in coastal areas and during certain times of the year, their diet can be composed primarily of greenery. Digestion of this coarse food, high in cellulose, is made possible by the protozoan intestinal fauna. In addition to breaking down the cellulose these protozoan symbionts also provide several essential vitamins – biotin, riboflavin, niacin and folic acid.
In the quail’s digestive tract the protozoans are most abundant in the caeca (two blind appendages extending from where the large and small intestines join). The size of the caeca varies depending on the diet, with birds who are eating mainly seeds having smaller caeca than those consuming more green roughage. As the diet changes the size of the caeca changes too. Quail could not survive on a diet of green plants without the aid of these protozoans in their digestive tract. According to A. Starker Leopold in the book “The California Quail” the genera of protozoans involved in quail digestion are Trichomonas, Eimeria and Eutrichomastix. These organisms are also associated with disease in man, reptiles, fish, and other birds and mammals.
Quail chicks get their original “seeding” of the protozoans by pecking at and injesting their parents’ droppings.
Protozoans also are symbionts in domestic fowl, turkeys, pheasants and other gallinaceous birds, a fact that brings up the question of interspecies transmission. . .
Perhaps I should simply watch the California quail scratch and peck.