Water Turnover in Roadrunners under Different Environmental Conditions

Abstract

THIS study reports on the use of tritiated water (HTO) to determine total body water and the kinetics of the water pool in captive Roadrunners (Geacoccyx californianus). The Roadrunner is an interesting subject for the study of water turnover, as it occurs in the most arid regions of North America (Grinnell, 1907), consumes primarily animal material (Bryant, 1916), will drink water in the field (Sutton, 19140), but apparently does not require it (Miller and Stebbins, 1964; Ohmart, field observ.). In addition, data on its water losses and requirements are available (Calder and Schmidt-Nielsen, 1967; Calder and Bentley, 1967; Calder, 1968a, 1968b). To our knowledge, this is the first reported attempt to use the HTO (tritiated water) technique to determine body water loss in nondomesticated or desert dwelling birds under two different environmental conditions.