Contribution of gular flutter to evaporative cooling in Japanese quail

Oxygen consumption, body temperature (Tb), and evaporative water loss (mwe) were determined in intact Japanese quail (Coturnix coturnix), and in quail in which the hyoid musculature responsible for gular flutter had been surgically transected several days prior to study. Abolishing gular flutter reduced total mwe by an average of 20% at air temperatures (Ta) above 40 degrees C. Treated birds developed a significantly greater degree of hyperthermia during acute heat stress than the controls and, unlike the controls, were unable to maintain Tb less than Ta above 40 degrees C. These data demonstrate that gular flutter represents a significant cooling mechanism in heat-stressed quail.