Date of Award
Level of Access Assigned by Author
Master of Science (MS)
Wildlife Ecology and Wildlife Conservation
Second Committee Member
Third Committee Member
Additional Committee Members
Understanding population dynamics and how species interact with their environment are important components for conservation and management. Ruffed grouse (Bonasa umbellus) are a widely distributed and common game bird in North America and are a considered an important economic and cultural icon in Maine. Although they are a well-studied species, there has been little research focused on ruffed grouse population dynamics and habitat relationships in Maine. My thesis aims to improve this knowledge gap by focusing on research related to survival and harvest of ruffed grouse, as well as male ruffed grouse resource selection at breeding display sites. Ruffed grouse are generally considered abundant in Maine, but there is a lack of states specific knowledge of their survival and harvest rates to inform harvest management. To address this component we estimated seasonal and annual survival rates, harvest rates, and documented cause-specific mortality of 248 radio-marked ruffed grouse at two study areas in central Maine from 2014 –2016. We used nest survival models implemented in Program MARK to evaluate sources of spatial, temporal, and individual variation that may affect survival and harvest. Our results showed survival was lowest during the month of October and during winter, and adult ruffed grouse had a higher survival probability than juveniles throughout the year (β -0.49 ± 0.15 SE). Harvest rates were greater in a state owned Wildlife Management Area, and were lower at our study area comprised of commercially-managed private forest (β=0.72 ± 0.38 SE). Pooled across all years and study areas, the ruffed grouse harvest rate was 0.16 (95% CI = 0.14-0.18). Our results are comparable to other range-wide studies, and suggest that ruffed grouse hunting regulations in Maine produce rates of harvest that are consistent with sustainable population management. Resource selection reflects behavioral choices that species make at different levels within their environment, but the fitness consequence of these choices are not always well understood. We evaluated habitat selection at breeding display sites, and the effects on breeding behavior, of male ruffed grouse in central Maine during April and May 2015–2016. We used resource selection functions (RSFs) that took the form of generalized linear models to compare habitat characteristics at used display locations (n=72) with those at available locations (n=144), and we further assessed how selected habitat features from the RSFs were associated with three drumming display characteristics; drumming rate, and wing beat rate. We used Akaike’s Information Criterion to assess model support and selection. We found that male ruffed grouse selected drumming locations with high total stem density (β=0.52, 95% CI= 0.22-0.82), as well as high conifer stem density within 5m from the display stage (β= 0.46, 95% CI= 0.17-0.75). However we did not find that these same variables were associated with drumming behaviors, suggesting no effect of habitat selection on breeding display behavior. Understanding habitat selection and the possible fitness consequences of those selection choices will allow managers to identify areas of critical habitat needed to further benefit the species.
Davis, Samantha, "Survival, Harvest, and Drumming Ecology of Ruffed Grouse in Central Maine, USA" (2017). Electronic Theses and Dissertations. 2784.