Movements and Habitat Use of White-Tailed Deer in Minnesota

Abstract

Radio transmitters were placed on six white-tailed deer (Odocoileus virginianus) in the winter of 1963-64 and eight deer in the winter of 1964-65 and their movements followed with an automatic tracking system. Winter home ranges were between 400 and 1,200 acres. Monthly home ranges were between 422 and 576 acres for the months January through March, 1964 and between 83 and 576 acres for the same months in 1965. Home ranges decreased with increased snow depth. The mean percentage of time associated with a cedar swamp changed from 74 percent during the day in January, 1964 to 17 percent during the night in March, 1964, while it changed from 73 to 88 percent during the same periods in 1965. Migration of seven radio-tagged deer occurred shortly after snow melted in fields in midApril, 1965, but was between late April and early May for three deer in 1964 when snow was mostly gone in March. Does and juveniles moved with practically no meandering from their winter to summer range while adult bucks seemed more inclined to wander. This paper reports on winter home ranges, gross analysis of vegetation types within these home ranges, and spring migration of white-tailed deer in east-central Minnesota. Data were obtained by placing radio transmitters on the deer and following them with the automatic tracking system located at the Cedar Creek Natural History Area (CCNHA) (Cochran et al. 1965). Six deer were radio-tagged during the winter, 196364 and eight during the winter of 1964-65. In addition, three deer were ear-tagged in February, 1965. Much of our data is relevant to the phenomenon of during the winter. However, our objectives were to determine gross movements and gross habitat usage of deer in the area, and the study was not designed to determine how and why deer yard. Ozoga (1968) has reviewed the relevant literature on yarding and reported on microclimatic differences that exist among 1 Supported by the U. S. Atomic Energy Commission, COO-1332-43, and by PHS Training Grant No. 5 to 1 GM01779-01 from the National Institute of General Medical Sciences. Computer time was provided by the University of Minnesota Numerical Analysis Center. 2 Present address: Department of Wildlife Ecology, University of Wisconsin, Madison, 53706. 366 various food and cover components of a conifer swamp deeryard. Although radio transmitters would be a valuable aid in a deer-yarding study and in relating deer behavior with microclimatic conditions, locations based on triangulation (Heezen and Tester 1967:126) would in most cases not be accurate enough for microclimate interpretation. Portable receivers would be needed to determine exact locations (whether the deer was under a tree or beside it). Because getting exact locations usually disturbs the animal, and because we tried to keep human influence on our study area to a minimum, we settled for gross determinations. Habitat within the study area has been described in detail by Pierce (1954), Bray et al. (1959), and others. For purposes of interpreting use of the available habitat by deer in winter, the types of communities in the 16 square miles containing and surrounding CCNHA were subjectively categorized as follows: 64 percent upland (23 percent woods, 41 percent fields); 32 percent lowland (18 percent marsh, 14 percent wooded swamp); and 4 percent open water. White cedar (Thuja occidentalis) of varying density occurs in about one-fourth (350 acres) of the wooded swamp; the remainder MOVEMENTS OF DEER IN MINNESOTA Rongstad and Tester 367 is characterized mainly by alder (Alnus rugosa) and tamarack (Larix laricina). About half of the fields in the area were cultivated while the others had been retired from cultivation for various periods of time. The main crops were corn (Zea mays), soybeans (Glycine max), alfalfa (Medicago sativa), and rye (Secale cereale). Corn was usually all picked by December 1, but enough waste corn remained to provide food for deer. Deer were present on CCNHA throughout the year, but the number increased during the winter when animals moved into the area. We suspect that this movement is related to the cedar swamp which is the only conifer swamp cover for many miles around. Ozoga (1968) found that mature swamp conifers offered deer the best protection from cold and the least hazardous snow conditions of six habitat types studied. We are grateful to K. L. Heezen and J. C. Moulton who captured and marked the deer as part of their thesis research, and to the many personnel of the Radio Tracking Project who assisted them in both field and laboratory aspects. W. H. Marshall and A. Peterson of CCNHA provided facilities and field assistance. D. B. Siniff generously assisted with computer processing of the data.