Abstract
The present study elucidated the relationship between daytime body temperature dynamics in male painted quail (Synoicus chinensis) with atmospheric pressure fluctuations. Atmospheric pressure was measured by three sensors positioned at the corners of an equilateral triangle with a side length of 18-20 km. The birds and the fourth pressure sensor were positioned in the center of this triangle. We demonstrated that body temperature dynamics correlated only with atmospheric pressure fluctuations recorded simultaneously by all sensors. This indicates that the ultradian body temperature rhythms in quails within the 10-30-min period range are linked not to the direct influence of atmospheric pressure, but rather to a factor generated during large-scale pressure fluctuations, or this biotropic factor itself is the cause of the observed atmospheric pressure fluctuations. It was also shown that the phase of these ultradian rhythms depends on local solar time, indicating that they are externally determined, possibly by the movement of the solar terminator.