Initial movements and disturbance response of a newly reintroduced elk herd in the Missouri Ozarks
Abstract
Initial movements of reintroduced wildlife populations can determine shortterm restoration success. Managers need ways to encourage animals to exhibit high release site fidelity so that they can mitigate suboptimal breeding, reduce mortality rates, and minimize human-wildlife conflicts that are sometimes associated with low site fidelity. We studied initial movement ecology of adult and yearling elk (Cervus elaphus) reintroduced to the Missouri Ozarks in 2011 (n=32), 2012 (n=21), and 2013 (n=31) for the initial 6 months post-release. All released elk were fitted with GPS collars which obtained locations at 2-5 hour intervals. We assessed maximum displacement from the release site, range shifts, movement rates, and range size across 4 sequential time frames (0-10 days, 11-31 days, 32-62 days, and 62-183 days) for animals surviving the study duration. We fit repeated measures mixed models to assess the effects of sex, age, calf-rearing status, release site, and release year on movement responses. Elk acclimated to their environment in discrete phases, including 1) immediate departure from the release site and elevated movement rates, followed by 2) establishing a home range and gradually expanding their range using previously used area. Individual maximum distances from the release site were stable for 0-61 days, and somewhat higher for 62-183 days. Compared to other restorations in eastern North America, site fidelity was high, with maximum distance from the release site 62-183 days post-release d10 km for 94% of 2011 animals, 57% of 2012 animals, and 97% of 2013 animals. The speed of elk movements declined slightly 10-61 days post-release, but were 30% higher in the last time frame. The average speed of individual elk across all time frames was 0.080??0.024 km per hour in the 2011 release group (n=32), 0.101??0.026 km per hour in 2012 release groups (n=21), and 0.091??0.025 in the 2013 release group (n=31). Elk range sizes were similar for 0-61 days post-release and approximately twice as high for
Degree
M.S.