|모든 저자 / 참여자:
C J Martinka
||Fig. 1. The study area, Bear Paw Mountains, north-central Montana.
Fig. 2. Seasonal observations of white-tailed and mule deer on various habitat types May, 1965, through September, 1966.
A study was conducted from June, 1965, through March, 1967, in the Bear Paw Mountains of north-central Montana to obtain quantitative data on range use and food habits of mule deer (Odocoileus hemionus) and white-tailed deer (O. virginianus) on areas of cohabitation. Observations of 641 mule deer and 437 white-tailed deer were recorded on 134 vehicle and foot trips through the study area. Mule deer utilized the bunchgrass habitat type more consistently than other types. Use was less during summer when increased use was made of willow-meadow and alfalfa types. Alfalfa reached maximum importance during fall. White-tailed deer showed a more distinct preference than mule deer for alfalfa and woody, deciduous-leaved habitat types. They used principally bunchgrass, aspen, and alfalfa types during spring and willow-meadow and alfalfa types during summer. Use of the aspen type increased during fall; it received nearly ¾ of the recorded winter use. Rumen samples from 27 mule deer and 25 white-tailed deer were analyzed. Relative use of forage classes by season was comparable for the two species with some minor differences. Many species of browse, forbs, and to a lesser extent grass, were eaten by both whitetails and mule deer during spring, summer, and fall. During winter, when forage was least available, browse formed the largest portion of the diets. White-tailed deer fed mostly on western serviceberry (Amelanchier alnifolia) and quaking aspen (Populus tremuloides). Mule deer utilized these species plus creeping juniper (Juniperus horizontalis). Differences in range or forage use during most seasons precluded competition between the two deer species. There was potential competition for western serviceberry on the shrub type during mild winters and on the bunchgrass, pine-bunchgrass, and shrub types during more severe winters.