The growing use of public lands for nature-based recreation has prompted a demand for research evaluating recreational use and its direct and indirect effects on wildlife populations and their habitat. Although a growing body of research has reported numerous negative effects that recreational use can have on wildlife resources, recent research has demonstrated that suitable habitat may mitigate the effects of human-wildlife interactions. In Michigan, the Pigeon River Country (PRC) and Atlanta (ASF) State Forests serve as the core range of Michigan's elk (Cervus elaphus nelsoni) herd. The PRC is a Special Management Unit that limits certain trail-based recreation types (e.g., equestrian use, mountain biking) to designated trails and prohibits some motorized vehicles (e.g., ORVs). Our primary goals were to examine the interactions among elk space-use and resource selection patterns, habitat suitability and potential, and summer trail-based recreation on public lands in the Michigan elk range. For our first objective, we developed habitat suitability index (HSI) and habitat potential models for elk within the Michigan elk range. Our HSI models indicated areas of high habitat suitability and potential for winter thermal cover, winter food, and spring food throughout the elk range. For our second objective, we quantified and compared the intensities and group sizes of common summer trail-based recreation types (i.e., equestrian use, hiking/foot-traffic, mountain biking, ORV use) at different temporal scales (i.e., year, month, day, hour) in the PRC and ASF. Recreation was monitored using trail cameras and we captured 11,412 recreation events during 263,664 hours of monitoring in the PRC, and 5,034 events during 266,184 hours in the ASF from May⁰́₃October, 2016⁰́₃2018. Greater recreational intensity was detected for all recreation types in both regions during September, weekends, and mid-day (11:00⁰́₃16:59). The most frequently detected types of recreation were equestrian use (58.8% of events) in the PRC and ORV use (51.8% of events) in the ASF. Our third objective was to evaluate and compare space-use and resource selection patterns for Michigan elk in response to habitat suitability and the intensity of summer equestrian use, hiking, mountain biking, and ORV use at different temporal periods. Global positioning system (GPS) collars were placed on 27 cow and 26 bull elk from 2016⁰́₃2018. Dynamic Brownian bridge movement models were used to quantify elk space-use patterns, and elk resource selection was modeled at landscape- and home range-scales. Elk home range sizes in May were 1.3⁰́₃2.0 times greater (P < 0.05) than in June⁰́₃September. Weekends accounted for 36% of the greatest daily elk movement distances. Elk demonstrated changes in the proportional use of cover types within home ranges during peak periods of recreational intensity. For our fourth objective, we evaluated the behavioral responses of elk to experimental recreational events. During September 2018, we monitored 69 equestrian use and 3 mountain biking events using handheld GPS receivers. We evaluated elk responses to encounters with recreation events that occurred within 2 times the average documented flight distance (60 m) for elk in Michigan. We recorded 4 encounters with the same cow elk during our events, and found no responses or changes in habitat use from encounters with recreation events. Our results highlight the need to consider the varying effects of different types of recreation on wildlife populations and the amount and quality of habitat components that may mitigate negative effects of interactions between wildlife and recreational users. Achieving a balance of interactions among wildlife, wildlife habitat, and recreational users is essential for ensuring long-term sustainability of wildlife populations, habitat, and recreational opportunities on public lands.
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