Comparative Winter Diets of Elk in New Mexico

Abstract
Winter diet quality of C. c. nelsoni was studied in the Jemez Mountains, New Mexico, during Jan.-April 1980 on a recently burned montane area (BURN) and an unburned upper montane area (BACA). Grasses dominated diets in the BURN, but nearly equal proportions of browse and grass were eaten in the BACA. Botanical composition of diets did not vary during the study at either site. Crude protein and in vitro digestible organic matter (IVDOM) in forages did not differ between locations. Grasses were more digestible than browse, but crude protein content was similar between forage classes. IVDOM and protein increased significantly in grasses with advancing season but not in browse. Dietary protein ranged from 3.5 to 7.2% in the BURN and from 4.7-7.5% in the BACA and was consistently superior in the BACA. Diet IVDOM in the BURN surpassed that in the BACA. Increases in diet quality were correlated with changes in quality of grasses ingested by elk. Forage quality was more variable than was diet quality, indicating the ability of elk to maintain relatively constant diet quality when confronted with large fluctuations in forage quality.