Hematological Studies in Birds

Hematological studies carried out on several aspects of the biochemistry and physiology of birds have been increasing, in particular those concerned with the determination of normal values of blood parameters. Avian hematology has been used in ornithological studies, because it gives biological data for these animals, their biology, and the detection of possible pathological states. Determination of nutritional and physiological condition, by the use of some biochemical components, can be very important in the understanding of ecological and behavioral problems. Nevertheless, some precautions must be taken. Hematological values, including chemical components, are known to be influenced by many factors: physiological state, age, sex, nutritional condition, circadian rhythm, seasonal changes, and others (Okumura and Tasaki 1969; Twiest and Smith 1970; Gee et al. 1981; Chaplin et al. 1984; Ferrer et al. 1987; Garcia-Rodriguez et al. 1987a, 1987b). So, when we try to study the effect of one of these factors, we must be sure that the others are under control.