COMPARATIVE REPRODUCTIVE AND PHYSIOLOGICAL-RESPONSES OF NORTHERN BOBWHITE AND SCALED QUAIL TO WATER-DEPRIVATION

We compared reproductive and physiological responses of captive female northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) under control and water deprivation conditions. Scaled quail required less food and water to reproduce successfully under control conditions than northern bobwhite. Additionally, in scaled quail, seru m osmolality levels and kidney mass were unaffected by water deprivati on, whereas in northern bobwhite, serum osmolality levels increased an d kidney mass declined. This finding indicates that scaled quail may h ave osmoregulatory abilities superior to those of northern bobwhite. U nder control conditions, northern bobwhite gained more body mass and p roduced more but smaller eggs than scaled quail. Under water deprivati on conditions, northern bobwhite lost more body mass but had more layi ng hens with a higher rate of egg production than scaled quail. Our da ta suggest that northern bobwhite allocated more resources to reproduc tion than to body maintenance, while scaled quail apparently forego re production in favor of body maintenance during water deprivation condi tions. (C) 1998 Elsevier Science Inc.