Effects of Corn Food Plots on Wild Turkeys in the Upper Mississippi Valley

Abstract

The hypothesis that corn food plots enhance overwinter survival of wild turkeys (Meleagris gallopavo) was examined in southeastern Minnesota. Two distinct populations of wild turkeys were studied during winter, one occupying an area where corn food plots were present and one in an area where they were not. Data were recorded for 328 birds captured and 154 that were radio-tagged. Five parameters were examined: activity patterns, home range size, habitat use, body weight, and survival. No differences in weight or survival were evident between the 2 populations during a winter of little deep snow. During a winter with persistent deep snow, birds relying on natural food resources showed substantial weight losses (P < 0.05) and mortality exceeded 60%. Birds using corn showed no weight loss and mortality was less than 10% of the population. J. WILDL. MANAGE. 44(2):456-462 Winter conditions have been recognized as having marked effects on wild turkeys in northern regions. Investigations in the past 10 years have shown that the critical facet of the winter environment is snow depth. Specifically, snow depths in excess of 25 cm limit the bird's ability to move (Austin and DeGraff 1975) and, therefore, its ability to locate and exploit food resources. Prolonged periods of deep snow can result in extensive mortality (Wunz and Hayden 1975, Wanless 1976). Turkeys in the upper Mississippi Valley inhabit a region where snow often restricts them to less than 10% of their normal range (Porter 1977a). Further, spring seeps, which have been shown to be important feeding habitat in the eastern United States (Healy 1977), do not occur commonly in this region. Production of mast, another important food resource, is frequently poor. As a result, historical populations fluctuated violently, periodically going extinct (Schorger 1942). In the past century, land-use patterns have altered the environment in the upper Mississippi Valley and have created a new food resource potentially important to turkeys. Throughout this region hardwood forests are interspersed with agricultural fields. At times, these fields contain an abundance of unharvested or waste grain. Partial fields of standing corn are frequently left on publicly owned lands or purchased on private lands under the auspices of the regional whitetailed deer (Odocoileus virginianus) management program. Corn is a highly nutritious food for domestic turkeys (Waibel and Burke 1973), and small fields of standing corn could constitute an important food resource for wild turkeys. Early work in Minnesota suggested that turkeys would use small fields of stubble or standing corn during the winter (Porter 1977b). This paper examines the hypothesis that small fields of standing corn (0.5-5.0 ha) placed near winter cover would enhance overwinter survival of 1 Research supported by National Institutes of Health Training Grant 5 T01 GM01779, The Minnesota Department of Natural Resources, the Minnesota State Archery Association, and the Special Projects Committee of the Minnesota Big Game Club. 2 Present address: College of Environmental Science and Forestry, State University of New York, Syracuse, NY 13210. 456 J. Wildl. Manage. 44(2):1980 This content downloaded from 207.46.13.51 on Tue, 21 Jun 2016 05:18:41 UTC All use subject to http://about.jstor.org/terms EFFECTS OF FOOD PLOTS ON WILD TURKEYS. Porter et al. 457 turkeys. The paper is taken from a more general study of the ecology and behavior of the turkey in southeastern Minnesota (Porter 1978). We acknowledge D. B. Siniff, J. R. Tester, and H. B. Tordoff of the University of Minnesota; and H. Shepperd, R. Johnson, N. Gulden, and G. Meyer of the Minnesota Department of Natural Resources for support of this project. We thank B. Neil, P. Loegering, T. Keefe, P. Owicki, C. Hutchison, and K. Haroldson for field assistance.