Agronomy and Horticulture Department
Date of this Version
5-2012
Abstract
Greater prairie-chickens (Tympanuchus cupido pinnata) are a grassland bird species of conservation concern. Although greater prairie-chickens have declined over much of their range, the Nebraska Sandhills has the largest population in North America. However, the responses of nest and brood site selection and survival to vegetation characteristics are unknown. I studied prairie-chickens on private rangelands in Rock and Brown Counties from 2009-2011. I fitted 139 females with radio collars to locate nest and brood sites and to determine nest and brood survival rates. Females were trapped on leks during the breeding season and I monitored them throughout the summer using radio telemetry. At nest and brood sites, I collected vegetation structure and composition data. Plant composition was estimated by functional groups using a quadrat method and vegetation structure was measured using the Robel pole and coverboard. I identified the ecological site and plant community at each nest and brood site. I then sampled to determine the relative availability of ecological sites and plant communities in each pasture to assess preference at a macroscale level. I also collected weather data throughout the reproductive season to assess variation in nest and brood survival. Prairie-chicken females tended to choose upland ecological sites for nesting and brood-rearing. Nest sites had more vegetation cover (VOR) (mean VOR: 10.8 cm; SD=0.7) than coupled random sites (mean VOR: 4.6 cm; SD=0.4). Nest site selection is positively associated with moderate levels of VOR and residual vegetation. Daily nest survival was poorly associated with habitat measures and was marginally associated with weather and temporal effects. Brood-rearing sites tended to have higher VOR and LD (mean VOR: 6.92 cm, SD=0.62; mean LD: 0.06 cm, SD=0.1) than at coupled random locations (mean VOR: 6.45 cm, SD=0.37; mean LD: 0.05 cm, SD=0.1). Higher forb cover and greater litter depth positively impacted daily brood survival. My research gives grassland managers much-needed information for managing prairie-chicken breeding habitat in the Nebraska Sandhills.
Comments
A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Agronomy, Under the Supervision of Professors Walter H. Schacht and Larkin A. Powell. Lincoln, Nebraska: May, 2012
Copyright (c) 2012 Lars C. Anderson