Avoidance of High-Potassium Diets by Captive Meadow Voles

We investigated whether meadow voles (Microtus pennsylvanicus) avoid high-potassium diets as a possible means of minimizing the physiological effects of high intake of potassium. When presented simultaneously with two diets of differing potassium content, captive voles consistently consumed more of the diet with lowest potassium content; selectivity increased with increasing disparity in the potassium content of the two diets. This selectivity occurred despite the lack of effect of dietary potassium content on survival or maintenance of body mass.