Habitat Selection of Reintroduced Bison in Northern Illinois

摘要

In one of the first reintroductions of a semi-wild population of bison (Bison bison) east of the Mississippi River, The Nature Conservancy reintroduced bison to the Nachusa Grasslands in northern Illinois in October 2014. Given the novelty of such efforts, questions remain regarding how human activity and prairie management affect bison habitat selection. My objective was to quantify bison habitat selection during 2014-16 to address literature gaps while investigating seasonal and annual changes. In October 2014, The Nature Conservancy collared 7 female bison with Lotek Iridium TrackM 3D and 4D collars programmed to take hourly locations. I randomly selected 1 bison location each hour to represent herd location and divided the resulting locations by season. Using resource selection functions, I compared the influence of land cover type, fire management, and concentrated human activity on habitat selection across seasons and at 2 scales: patch and enclosure. Land cover was consistently the best-fit model across seasons and scales with the exception of Winter 2016 at the enclosure scale. Bison strongly selected for partial restorations but showed no strong seasonal land cover selection trends. Bison selected for recently-burned prairie with the exception of Summer 2015 at the enclosure scale. At the patch scale, bison selected for areas closer to disturbed areas but did not show a strong trend at the enclosure scale. With a better understanding of how bison grazing is influenced by restoration management, wildlife managers can make better-informed decisions regarding bison restoration and public use.