The study compared the daily mean intensity of one-minute-step fluctuations in intensity of the secondary cosmic rays reflected by neutron count rate and dynamics of body temperature, motor activity, as well as concentration of glucocorticoid hormones in birds and rodents. A positive correlation was established between body temperature oscillations and neutron count rate fluctuations. A similar correlation was observed between physical parameter (neutron count rate), on the one hand, and daily mean motor activity and concentration of glucocorticoid hormones in the animals. The periods and phases of these processes presented in synchronous time series coincided. The facts of simultaneous variations or disturbances of the periods in dynamics of biological and physical parameters attest to their relationships. The study concluded that the infradian rhythms with the periods of 3-5 days depend on some external environmental factor related to fluctuations in intensity of secondary cosmic rays.