We flew aerial line-transect surveys to estimate the range-wide population size of lesser prairiechickens (Tympanuchus pallidicinctus) in the Great Plains, United States in 2012 and 2013. We also estimated the number of lesser prairie-chicken leks, the number of mixed-species leks that contained both lesser and greater prairie-chickens (T. cupido) and the number of hybrid lesser-greater prairie-chickens where these species' ranges overlap. The study area included the 2011 estimated occupied lesser prairie-chicken range in 5 states and was divided into 4 ecoregions. We created a sampling frame over the study area, consisting of 536 15-Â 15-km grid cells. We flew 512 transects within a probabilistic sample of 256 cells totaling 7,680 km in 2012 and 566 transects within a probabilistic sample of 283 cells totaling 8,490 km in 2013. We estimated a total of 34,440 individual lesser prairie-chickens in 2012 (17,615 in 2013) and 350 hybrid lesser-greater prairie-chickens in 2012 (342 in 2013) in the study area. We estimated a total of 2,930 lesser prairie-chicken leks in 2012 (2,037 in 2013) and 453 lesser and greater prairie-chicken mixed leks in 2012 (356 in 2013) in the study area. We discuss the implications of alternative sampling designs with regard to conservation questions to be addressed. Ó 2014 The Wildlife Society.

Under the Bald and Golden Eagle Protection Act, the United States Fish and Wildlife Service (Service) can authorize take of golden eagles (Aquila chrysaetos), such as nest removal, disturbance, and lethal take, if the take is compatible with the preservation of the golden eagle. The Service needs baseline information on the current abundance and trend of subpopulations of the golden eagle to properly manage take of the species. Annually during late summer of 2006-2012, we used distance sampling on approximately 17,500 km of aerial line transects to estimate golden eagle abundance in 4 Bird Conservation Regions (BCRs; North American Bird Conservation Initiative Monitoring Subcommitte 2007) that collectively cover about 80% of the species' range in the coterminous western United States. We estimated study area abundances of 24,509 (90% CI: 19,406-31,947) in 2006 and 21,715 (90% CI: 18,165-27,624) in 2012, including all breeding and non-breeding individuals. We used a Bayesian hierarchical model to estimate trends in individual BCRs and the entire study area based on numbers of golden eagles counted along surveyed transects. We detected declines (90% credible intervals [CRIs] for trend coefficients <0.0) in numbers of golden eagles classified as juveniles in BCR 10 (Northern Rockies) and BCR 16 (Southern Rockies and Colorado Plateau) during 2006-2012. However, our results indicate the total abundance of golden eagles has not declined 2006-2012 in much of the western United States. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

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EDP Renewables (formerly Horizon Wind Energy) has proposed a wind-energy facility in Carbon County, Wyoming. The Simpson Ridge Wind Resource Area (SRWRA) provides habitat for greater sage-grouse, a federal candidate species considered warranted but precluded for listing under the Endangered Species Act. The objectives of this study included 1) Evaluate and determine the functionality and viability of greater sage-grouse habitat within the influence of the proposed Simpson Ridge wind energy development project; and 2) Determine the population impacts of the wind energy project on greater sage-grouse within the influence of the project.This study was conducted in an area with two proposed wind energy facilities and one existing wind-energy facility. Our general approach was to compare greater sage-grouse habitat selection and demographics on proposed wind energy development areas pre versus postconstruction of the wind energy facilities to determine if wind-energy facilities influence grouse distributions or population growth. The first two years of study were designed to collect data on greater sage-grouse populations in and near the SRWRA necessary to determine pre-treatment seasonally selected habitats (e.g., nesting areas, brood-rearing areas, lek visitation, summer habitat, and winter habitat) and population-level vital rates (e.g., productivity and survival). The presence of an existing wind energy facility in the project area allowed us to obtain some information on initial sage-grouse response to wind turbines the first two years following construction. To our knowledge these are the first quantitative data on sage-grouse response to an existing wind energy development. The purpose of this report is to present results of the first two full years of data collected from April 1, 2009 through March 30, 2011. This study was selected for continued funding by the National Wind Coordinating Collaborative Sage-Grouse Collaborative (NWCC-SGC) and has been ongoing since March 30, 2011; however, the focus of the study switched from collecting pre-construction data for the SRWRA to collecting post-construction data for the existing 79-turbine PacifiCorp Seven Mile Hill wind energy facility. Future reports summarizing results of this research will be distributed through the NWCC-SGC.The SRWRA encompasses 28,600.92 acres in Carbon County, Wyoming, between the towns of Hanna and Medicine Bow, and south of US Highway 30. The SRWRA contains numerous ridges interspersed with rolling to hilly plains. Elevations range from 6,700-7,840 feet above sea level. The SRWRA is situated near the base of the Snowy Range Mountains to the south, and lies south of the Shirley Basin. Climate is classified as a semiarid, cold desert with mean annual precipitation of 12 inches (30.5 centimeters [cm]). The SRWRA is almost entirely (96.7%) comprised of scrub-shrub, with the dominant shrub being Wyoming big sagebrush. Grassland composes an additional 1.9% of the study area. All other habitat types each compose less than 1% of the area individual...