Publisher Summary This chapter presents a study on the oxygen storage and blood transport as adaptations for flight in birds. In this study, three species of birds representing different levels of activity were analyzed: (1) the quail (Coturnix coturnix), (2) the starling (Sturmus vulgaris), and (3) the pigeon (Columba livia). The pigeon was studied in two different situations: (1) in confinement, and (2) in sustained flight, after progressive training, for distances ranging from 10 to 300 km in which they hold up average speeds of about 80 km/h. The hematocrit, hemoglobin concentration, red blood cell number, blood volume, and the whole oxygen affinity were determined. The following intraerythrocyte organic phosphates were also analyzed: (1) ATP, (2) inositol polyphosphates, and (3) inorganic phosphates (Pi). No differences were found between the intraerythrocyte phosphates either in the total content or in the different fractions. In the same way, the pigeon did not reflect the strong activity revealed by weight loss (9%) and the hemoconcentration (10%) either in the amount of phosphates or in blood oxygen affinity. According to study data, the flight activity of the birds analyzed does not affect the blood oxygen affinity because of variations in the phosphate level although other aspects not considered such as the increase of body temperature and hyperventilation could possibly affect the oxygen affinity. These preliminary results point toward a certain inertia in the phosphates as seen by their steady levels in birds. In the same way, they were not altered during hypoxia, which is the opposite of what happen in mammals.
J. Palomeque, M. Rivera, J. Planas
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