Factors Limiting Deer Abundance in the Upper Peninsula

In the Upper Peninsula of Michigan, there are numerous factors that may act singularly or in combination to influence deer abundance. For instance, if food availability was greatly reduced, especially during critical times, or habitat that is essential for survival (such as deer yards) was reduced to below critical levels, it could have a drastic impact on deer populations. Likewise, if predators of deer increased to extreme numbers, deer populations could be kept low. These factors, and environmental factors can interact and can vary over space (across the Upper Peninsula) and time and can be complex to understand. Some of these factors have a greater impact on deer populations and thus are more important than others. In addition, some of these limiting factors can be managed by state wildlife agencies, while others cannot. We take an in-depth look at the important limiting factors which affect deer abundance in the Upper Peninsula and discuss the complex interactions among predators and prey in various life stages, their environment, abundance, and distribution (Appendix B, page 24). We use buck harvest as an indicator of trends in the deer population. Despite the limitations, buck harvest is the best data source relating to deer numbers that we have in Michigan (Appendix A, page 22). Much of the data in this report came from the Michigan Predatory Prey Research Project which investigated the role that winter weather, predators and habitat have on white-tailed deer survival from 2009-2020. For each graph or figure in the document, there are bullet points explaining the information. When appropriate, data sources are listed in italics at the end of each bullet point.