Differences in nutritional quality between herbaceous plants and bark of conifers as winter food for the vole Microtus pennsylvanicus.
Abstract
During winter 1987-88 and 1988-89 in Quebec, food quality (protein, total non-structural carbohydrates (TNC) and phenolics) was much greater, and varied less, in herbaceous plants (16 species) than in conifer bark (Picea abies, Pinus resinosa, Picea glauca and Pinus strobus). Ratios involving protein/phenolics and TNC/phenolics were up to 50× greater in herbs than in bark. Bark gnawing is attributed to a lack of good quality alternative food rather than food preference.