Sage‐grouse breeding and late brood‐rearing habitat guidelines in Utah

Abstract

Delineation, protection, and restoration of habitats provide the basis for endangered and threatened species recovery plans. Species recovery plans typically contain guidelines that provide managers with a scientific basis to designate and manage critical habitats. As such, habitat guidelines are best developed using data that capture the full diversity of ecological and environmental conditions that provide habitat across the species' range. However, when baseline information, which fails to capture habitat diversity, is used to develop guidelines, inconsistencies and problems arise when applying those guidelines to habitats within an ecologically diverse landscape. Greater sage-grouse (Centrocercus urophasianus; sagegrouse) populations in Utah, USA, reflect this scenario-published range-wide habitat guidelines developed through a literature synthesis did not include data from the full range of the species. Although all sagegrouse are considered sagebrush obligates (Artemisia spp.), the species occupies a diversity of sagebrush communities from shrub-dominated semideserts in the southwest to more perennial grass-dominated sagebrush-steppe in the northeast portions of their distribution. Concomitantly, local ecological site and environmental conditions may limit the ability of managers to achieve broader range-wide habitat guidelines. We combined microsite habitat vegetation parameters from radiomarked sage-grouse nest and brood locations with statewide spatially continuous vegetation, climatic, and elevation data in a cluster analysis to develop empirically based sage-grouse habitat guidelines that encompass the range of ecological and environmental variation across Utah. Using this novel approach, we identified 3 distinct clusters of sagegrouse breeding (i.e., nesting and early brood-rearing) and late brood-rearing habitats in Utah. For each cluster, we identified specific vegetation recommendations that managers can use to assess sage-grouse breeding and late brood-rearing habitat. Our results provide relevant guidelines to Utah's sage-grouse populations and are feasible given the unique ecological variation found therein. This approach may have application to other species that occupy diverse habitats and physiographic regions.

Predicting greater sage‐grouse habitat selection at the southern periphery of their range

“…Eighty-three percent of habitat that our model identified as selected over average conditions fell largely within the Utah SGMA boundaries (Figures 2 and 3). Similarly, Dahlgren et al 2016 activities are concentrated near leks (Dahlgren et al, 2016(Dahlgren et al, , 2019.…”

“…Precipitation also varies greatly, from an average of less than 12 cm annually over the Great Salt Lake Desert to more than 100 cm in the mountains (https://wrcc.dri.edu/narra tives/ UTAH.htm). Our study area encompassed known sage-grouse breeding habitats and distributions in Utah (Dahlgren et al, 2016(Dahlgren et al, , 2019…”

“…We followed a use-availability design (Manly et al, 2002) to model seasonal sage-grouse habitat selection. We modeled each season separately because we expected sage-grouse to select habitat differently during breeding, summer, and winter at our spatial scale of interest (Dahlgren et al, 2016(Dahlgren et al, , 2019. Therefore, we assigned sagegrouse used locations to breeding, summer, and winter seasons in accordance with Utah-specific breeding-date ranges identified by Dahlgren et al (2016).…”

“…Factors that affect sage-grouse distribution at the range-wide scale are likely to differ, at least partially, from features that influence habitat selection at finer spatial scales (Dahlgren et al, 2019).…”

“…The spectrum of ecological and environmental conditions available to sage-grouse in Utah encompasses the tails of the general distribution observed across the range (Stiver, 2006). For example, occupied sagebrush habitats in Utah consist of discontinuous patches at higher elevations than those found in other areas of the sage-grouse range (Dahlgren et al, 2016(Dahlgren et al, , 2019. Climatic regimes also differ in Utah as compared to other areas of the sage-grouse range, with generally lower annual precipitation (Dahlgren et al, 2016;West, 1983).…”