Date of Award
Master of Science
CHRISTOPHER R. BOTTOM, for the MASTER OF SCIENCE degree in ZOOLOGY, presented on XXXX at Southern Illinois University Carbondale. TITLE: HABITAT OVERLAP AMONG MESOCARNIVORES AND WILD TURKEYS IN AN AGRICULTURAL LANDSCAPE MAJOR PROFESSOR: Clayton K. Nielsen Wild turkey (Meleagris gallopavo) populations have grown considerably in the agricultural Midwest during the past few decades, as have mesocarnivores such as coyotes (Canis latrans) and bobcats (Lunx rufus) which may impact turkey populations. However, few studies have assessed habitat overlap between mesocarnivores and turkeys with a goal to understand potential impacts of mesocarnivores on turkeys. To address these gaps in the literature, my objectives were to (1) create single-species models of habitat use for bobcats, coyotes, and wild turkeys; (2) model habitat overlap among species; and (3) determine the influence of mesocarnivore habitat use on wild turkey nest success and mortality. I captured and radiomarked 14 adult bobcats (10 M, 4 F), 19 adult coyotes (11 M, 8 F), and 44 wild turkey hens (9 J, 34 A) during 2011-2013 in a complex agricultural landscape in southern Illinois. I developed single-species resource selection function models of habitat use for all 3 focal species and also developed habitat overlap models. In the single species models, wild turkey and bobcat use was concentrated largely in forested areas whereas coyote use was highest in agricultural areas. Overlap among species was common and occurred mostly in forested areas. I then used locations of 107 wild turkeys nests and 28 hen mortalities and modeled the effect of bobcat, coyote, and wild turkey use on turkey nest success and mortalities. Coyote presence was the best predictor of nest success, with increased coyote use associated with higher nest success. Wild turkey use was important in determining location of wild turkey hen mortalities, with increased turkey use associated with higher probability of mortality occurrence. My findings suggest that top predators may be important and beneficial for ground nesting avian species (e.g., wild turkey). Coyotes utilize many habitat types for foraging including forest edges, grasslands, and wetlands. These are abundant in a fragmented landscapes and also represent areas preferred by ground nesting bird species and other mesocarnivores. With coyotes acting as the top predator throughout much of the Midwest, they are likely reducing densities of other important turkey nest predator species, thereby increasing nest success. Although the study is not conclusive on its own, it is consistent with the predictions of the mesopredator release hypothesis.
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