Observed Use of Forage and Plant Communities by Black-Tailed Deer

Abstract

During 1964, 6,746 observations were made of known numbers of black-tailed deer (Odocoileus hemionus columbianus) within an enclosure on the Cedar Creek watershed within the Tillamook Burn, Oregon. These observations provide a basis of insight into the deer's use of vegetation within the enclosure. The interpretation centers around feeding and bedding behavior in relation to forage availability and plant communities. Indices of preference by deer for plant communities showed a spatial and seasonal nonrandom distribution of deer. Red huckleberry (Vaccinium parvifolium) was the principal browse plant; vine maple (Acer circinatum) and red alder (Alnus rubra) were unimportant as browse. Browsing of Douglas fir (Pseudotsuga menziesii) began with the first snow. Sightings of deer in the vine maple (Acer circinatum/Polystichum munitum) community were high every month. Deer presence in the huckleberry (Vaccinium parvifolium/Gaultheria shallon) community increased in late winter, peaked in May, and declined the rest of the year. In the big-leafed maple (Acer macrophyllum/Symphoricarpos mollis) community, deer sightings increased in late winter, declined in March and April, increased during the summer, and peaked in October. Relatively few deer were observed in the bracken fern (Pteridium aquilinum/Lotus crassifolius) and thimbleberry (Rubus parviflorus/Trientalis latifolia) communities. Occurrence of deer in the alder (Alnus rubra/Rubus parviflorus) community was highest in spring and fall. This study relates direct observations on feeding and bedding behavior of blacktailed deer to measured environment within an enclosure on the Cedar Creek watershed within the Tillamook Burn, Oregon. Interpretation of the data seeks insight into the deer's use of vegetation. Previous studies on the Burn were not based on direct observations of deer (Einarsen 1946, Chatelain 1947, Lightfoot and Hines 1960, and Crouch 1966). Acknowledgment is made to Dr. Thomas G. Scott, Department of Fisheries and Wildlife, Oregon State University; to Dr. Arthur W. Bailey, Weed Science and Crop Ecology, University of Alberta; and to William W. Hines, Division of Wildlife Research, Oregon State Game Commission, for critical reading of the manuscript. THE STUDY ENCLOSURE The study enclosure is in the Coast Range Mountains of northwestern Oregon, approximately 18 miles inland from Tillamook, on the Cedar Creek watershed in that portion of Tillamook County known as the Tillamook Burn. The elevation within the enclosure ranges from 800 to about 2,000 ft, measured from mean sea level. The enclosure is west of the summit, and it receives a mean annual precipitation of 130 inches, based on a 25-year average at Glenora 3 miles east of the study area (U. S. Weather Bureau 1936). Maritime influences result in cool, wet winters with prolonged snow cover sufficient to restrict deer travel at elevations above 2,000 ft. The summers are usually dry and hot, but small, permanent streams occur in the study