Variation in greater sage-grouse morphology by region and population

The greater sage-grouse (Centrocercus urophasianus) is wildlife species with important conservation and management considerations in western North America. Research on sage-grouse has established their historical and current distribution (Schroeder et al. 2004) as well as providing an assessment of their populations and habitats (Connelly et al. 2004). This research helped define the presence of 41 distinct populations (Fig. 1) based on the Berryman’s (2002) definition of a population; �"as a group of individuals of the same species that live together in an area of sufficient size to permit normal dispersal and/or migration behavior and in which numerical changes are largely determined by birth and death processes.

In addition to defining populations, research has provided an evaluation of the rangewide genetics of sage-grouse with an assessment of potential issues associated with population size, population connectivity, and sub-specific variation (Young 1994; Young et al. 1994; Oyler-McCance et al. 1999, 2005). Although research helped establish the Gunnison sage-grouse as a behaviorally and morphologically distinct species (Young et al. 1994), similar research within the remaining populations of greater sage-grouse has been somewhat limited (Oyler-McCance et al. 2005, Taylor and Young 2006). Oyler- McCance et al. (2005) showed that sage-grouse displayed relatively integrated genetics across their range with notable exceptions being the Moses Coulee, N Mono Basin, and S Mono Basin populations.

The initial objective of this research was to examine the availability of previously collected morphological and behavioral data from both published and unpublished sources. Although the collection of additional data would certainly aid in this process, this was not an objective for this initial phase of research. The overall goal of the research was to acquire and examine data with reference to variation associated with region, population, and/or previously established genetic characteristics. Because of the nature of this type of data (rarely published), it was believed that this initial report effort would be ‘preliminary’ and that analysis would continue as additional data was collected and/or acquired.