A multilocus population genetic survey of the greater sage‐grouse across their range

Abstract

The distribution and abundance of the greater sage-grouse (Centrocercus urophasianus) have declined dramatically, and as a result the species has become the focus of conservation efforts. We conducted a range-wide genetic survey of the species which included 46 populations and over 1000 individuals using both mitochondria1 sequence data and data from seven nuclear microsatellites. Nested clade and STRUCTURE analyses revealed that, in general, the greater sage-grouse populations follow an isolation-by-distance model of restricted gene flow. This suggests that movements of the greater sage-grouse are typically among neighbouring populations and not across the species, range. This may have important implications if management is considering translocations as they should involve neighbouring rather than distant populations to preserve any effects of local adaptation. We identified two populations in Washington with low levels of genetic variation that reflect severe habitat loss and dramatic population decline. Managers of these populations may consider augmentation from geographically close populations. One population (Lyonl Mono) on the southwestern edge of the species' range appears to have been isolated from all other greater sage-grouse populations. This population is sufficiently genetically distinct that it warrants protection and management as a separate unit. The genetic data presented here, in conjunction with large-scale demographic and habitat data, will provide an integrated approach to conservation efforts for the greater sage-grouse.

Low neutral genetic diversity in isolated Greater Sage-Grouse (Centrocercus urophasianus) populations in northwest Wyoming

“…In contrast, however, if the population has been small for hundreds of generations, deleterious traits may have been purged, and management should focus more on maintaining adequate habitat for long-term sustainability (e.g., Johnson et al 2009) as opposed to introgression of genes that may result in outbreeding depression (Frankham et al 2011 Table 2), it is not known whether the differentiation is largely due to a recent reduction in population size and drift or represents a long-term pattern of isolation, with long-term isolation of more concern relative to outbreeding depression. Multiple isolated populations have been identified in the Greater Sage-Grouse range based on genetic analyses (Oyler-McCance et al 2005). The Douglas-Grant and Yakima populations in Washington are small and isolated in a geographic region that has been more recently used for agriculture (Oyler-McCance et al 2005), suggesting a more recent pattern of isolation.…”

“…We chose 17 microsatellite loci based on previous Greater Sage-Grouse population genetic studies (Oyler-McCance et al 2005, Bush et al 2011. Microsatellite loci were originally developed for Greater Sage-Grouse (SGCA11.2, Caizergues et al 2003).…”

“…This species has experienced range-wide population contraction since European settlement of North America due to widespread sagebrush habitat alteration and loss (Schroeder et al 2004, Knick andConnelly 2011). Greater Sage-Grouse now occupy~56% of their preEuropean settlement distribution, and populations are becoming increasingly isolated ( Figure 1A; Schroeder et al 2004, Oyler-McCance et al 2005. In 2010 the U.S.…”

Z chromosome divergence, polymorphism and relative effective population size in a genus of lekking birds

“…We chose DNA samples from 30 sage-grouse (10 each from C. minimus, C. urophasianus and Bi-State) used in previous studies (Oyler-McCance et al, 1999, 2005a. Bi-State C. urophasianus and C. minimus samples were chosen so that we covered the entire range of those groups.…”

“…Greater Sage-Grouse (Centrocercus urophasianus) occupy much of the North American West, while Gunnison Sage-Grouse (Centrocercus minimus) are restricted to southwestern Colorado and southeastern Utah (Figure 1). Within C. urophasianus, the most genetically divergent population sampled to date spans the border between California and Nevada ('Bi-State population' hereafter), and was found to be at least as divergent from other populations of C. urophasianus as C. minimus is from C. urophasianus at the same mitochondrial and microsatellite loci (Oyler-McCance et al, 2005a), but is not distinct morphologically or behaviorally (Schroeder, 2008;Taylor and Young, 2006). Recent work with genomic methods, however, has shown that C. minimus is well differentiated from C. urophasianus and the Bi-State is also differentiated albeit more weakly .…”