For centuries the art of keeping and breeding birds has been practiced by aviculturists, who enjoy the companionship, beauty, and behavior of canaries, finches, parrots, and other aviary and cage birds. The science of aviculture is, however, still in its infancy except for some gallinaceous birds (chickens, turkeys, pheasants, and quail), domestic pigeons and doves, and some ducks and geese. For these food and game species, our scientific knowledge is good or sometimes excellent; for example, the nutrient requirements of poultry are well known, as are the effects of deficiencies or excesses of nutrients. In contrast, most companion birds are poorly understood with regard to needs for growth, maintenance, and reproduction. Some reasons for this disparity in information reside in the nature of the bird business, with its diversity of species and sizes of production units; the dependence of dealers on the supply of certain imported, wild-caught birds instead of on local breeders; and the difficulties of studying altricial birds, which depend entirely on their parents for early care, as compared with precocial birds, which can feed themselves immediately after hatching.

Dr. Grau has been a regular contributor to California Agriculture on the subject of poultry nutrition. His first article. “It's no longer ‘just chicken feed’,” appeared in the December 1946 issue, Volume 1, Number 1.