title: Evaporative cooling and water balance during flight in birds.
abstract: The rate of evaporative cooling was calculated from the rate of mass loss in starlings (Sturnus vulgaris) during 90 min flights in a wind-tunnel. Evaporative heat loss ranged from 5% of the metabolic rate at -5 degrees C to 19% of the metabolic rate at 29 degrees C. Radiation and convection accounted for the balance of the heat loss. On average, starlings dehydrated during flights at all temperatures above 7 degrees C. The comparison of these results with data from field studies, which indicate that long-distance migrants do not dehydrate, suggests that migrants may maintain water balance by ascending to colder air in which convection carries off most of the heat produced.
mesh_terms: D000818:Animals; D001717:Birds / Q000502:physiology*; D001833:Body Temperature Regulation; D001834:Body Water / Q000378:metabolism; D001835:Body Weight; D004734:Energy Metabolism; D005426:Flight, Animal; D014882:Water-Electrolyte Balance