Nesting ecology, survival, and home range of wild turkeys in an agricultural landscape

Most research on Eastern wild turkeys (Meleagris gallopavo silvestris ) has occurred in extensively forested habitats atypical of midwestern landscapes. I studied the ecology of female wild turkeys in a portion of southern Illinois consisting of an agricultural matrix interspersed with forest, and grassland cover types. I quantified causes of hen and nest mortality, nesting habitat variables, nesting rates, nest success, clutch and brood sizes, and incubation length. I also examined daily nest and weekly hen survival rates, and hen and brood home ranges and habitat selection. Sixty-four hens were radiomarked during 2008 -- 10. Predation was the primary cause of nest mortality (80.5%) and hen mortality (100.0%). Coyotes (Canis latrans) were responsible for 40.3% of nest mortalities and 42.8% of hen mortalities, whereas bobcats (Lynx rufus) caused 42.8% of hen mortalities. Weekly survival rates were 98.7 and 98.6% for adult and juvenile hens, respectively. Seasonal survival rates for adult hens varied from 68.7% during breeding to 88.9% during winter. Most hens (98.5%) made a first nest attempt, 75.6% of hens attempted a second nest, and 8.0% of hens attempted a third nest. Mean clutch size was 12.4 +/- 0.4 (SE throughout) during the first nesting attempt and 9.6 +/- 0.6 during the second nesting attempt. The mean incubation length of successful nests was 31.1 +/- 0.8 days. Mean nest success was 19.8%, producing 11.3 +/- 3.3 poults/per successful hen. Nests initiated early (1 Apr--31 May) had a higher success rate (27.0%) than late-initiated nests (1 Jun--30 Jul, 20.6%). Nests were located closer to forest cover, closer to roads, and further from agricultural edges than random locations. Nests had a greater presence of mid-successional species such as briars and vines than at random sites. Daily nest survival was 0.954. Visual obstruction of the nest at 4 m, the presence of trees/shrubs, and presence of grasses were the only covariates that explained significant variation in nest survival. Compared to failed nests, successful nests were closer to forest cover and roads. Hens mean home range size was 429.2 + 17.5 ha. During the 4-week brooding period, brooded hens used 97.6 + 8.1 ha. Greater than 83.3% of brooding locations were located in forest cover. Juvenile hens mean dispersal distance was 8.1 + 1.5 km. Roost trees selected by hens had a mean diameter at breast height of 64 cm, while 51.2% of the hen roost trees were white oaks (Quercus alba). Turkeys in southern Illinois selected a broad range of nesting habitat, with demographic rates similar to turkey studies conducted in more forested landscapes. Survival rates of turkeys in southern Illinois were also similar to other regions, although turkeys appear to disperse greater distances in this patchy agricultural landscape. Our research provides vital information for turkey populations and describes key habitat variables affecting turkey nest site selection and success. Wildlife managers can use this information to improve turkey populations in the Midwest.