We estimated heat production in Japanese quail (Coturnix coturnix japonica) by measuring oxygen uptake using open-circuit respirometry as ambient temperature was decreased gradually from 26 to 3.5 °C. At the same time, the intensity of shivering was estimated in both the leg muscles and the flight muscles by measuring electromyograms. Metabolic heat production increased in a linear fashion as ambient temperature decreased. Shivering intensity increased at the same linear rate in the leg muscles as in the flight muscles as ambient temperature decreased. The leg muscles produce a substantial fraction (about 1/4) of the total shivering heat production at low ambient temperatures. Shivering occurred in bursts; the onset of a burst in the leg muscles was precisely synchronized with the onset of a burst in the flight muscles.

Japanese quail's leg muscles contribute significantly to heat production at low ambient temperatures, with shivering occurring in bursts and synchronizing with flight muscles.

Contribution of shivering in leg muscles to heat production in Japanese quail

Key Takeaway: Japanese quail's leg muscles contribute significantly to heat production at low ambient temperatures, with shivering occurring in bursts and synchronizing with flight muscles.