| Michigan proudly boasts an elk herd heavily utilized by a wide array of stakeholders from across the Midwest with varying recreational interests. Recently, significant changes have occurred within and surrounding the elk range, which have created concern among elk managers that historical techniques and management strategies may no longer be adequate to address the current issues facing Michigan's elk. This project was initiated and designed to gain valuable information and develop new techniques that will provide elk managers with the knowledge and tools for successful management of one of Michigan's most unique natural resources. I developed a new population estimation procedure based on a sightability model framework using fixed-wing aircraft, which allowed for correction for visibility bias associated with missing elk groups. Incorporated into this technique was the ability to estimate group sizes, which reduced bias of population estimates and resulted in near nominal confidence interval coverage. Using this technique I estimated the Michigan elk herd to be approximately 905 (SE = 125). I collected 13,923 locations using triangulation procedures, and 728 visual observations of 58 radiocollared elk. I estimated individual home ranges for each animal using fixed-kernel estimation procedures, and determined that mean bull home range size (9,587 ha) was significantly larger than cow home range size (6,349 ha). Additionally, kernel surfaces were averaged to allow for population level inference about range use patterns. Analyses showed an uneven distribution of range use with many peaks in valleys in the probability density surface. There was considerable joint space use between elk from different summering areas based on dispersal patterns from capture sites, movement data and by examining the joint density surfaces calculated from the independent kernel density functions for each individual elk. Two large ranches in the center of the elk range, Black River and Canada Creek, received substantial use by elk throughout the year although use varies seasonally. Elk use within these ranches was highly localized, and changed in response to habitat manipulations. Also, movement patterns of bulls inhabiting Canada Creek Ranch indicated that these bulls are likely breeding bulls from across the range. Using the averaged kernel density surface, I demonstrated that management efforts focused on maintaining and enhancing wildlife openings are having the desired effect as elk used managed openings with a significantly higher probability than unmanaged openings. The elk range unfortunately lies within the endemic region for bovine tuberculosis (TB), which infects free-ranging deer in this area. Using the averaged kernel density with historical TB prevalence data, I identified high-risk areas for elk being exposed to TB. Three high-risk areas were delineated, and these areas corresponded well with locations of known TB positive elk. Lastly, I examined the range use patterns of a radiocollared cow that was infected with TB and her joint space use with other elk in the region. Results showed that this elk had a home range of 8,856 ha, potentially exposing numerous other individuals and species to infection either through direct or indirect contact. Elk population and management decisions must account for the dynamic movement patterns that exist in this region of the elk range to accommodate diverse recreational objectives. |
