Seasonal changes of food and water consumption and urine production of the marmot, Marmota flaviventris.

In early spring, food and water consumption and the excretion and clearances of urine and solutes reached maximal rates. Water consumption exceeded food intake and urine production and plasma osmolality was lowest. Toward early and late summer, water intake decreased faster than food consumption and urine production. Urea excretion and clearances diminished with food consumption, while creatinine clearance decreased only slightly. Plasma osmolality increased. The data are consistent with rehydration soon after hibernation is completed, followed by a period of weight gain and dehydration in preparation for the next prolonged period of hibernation.