•  
  •  
 

Abstract

Declines in greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse) populations in Utah over the last century parallel range-wide trends. However, little is known about the ecology of sage-grouse populations that inhabit Utah’s naturally fragmented habitats. Utah’s West Desert sage-grouse populations occupy sagebrush (Artemisia spp.) habitats that are geographically separated by the Great Salt Lake, and largely confined to the Sheeprock and Deep Creek watersheds. From 2005 to 2006, we monitored sage-grouse that were radio-collared in each watershed to determine the factors affecting the vital rates in these isolated populations. Livestock grazing by domestic cattle was the dominate land use, and mammalian predator control for livestock protection was conducted in both watersheds. Corvid control was conducted only in the Sheeprock watershed. During the study, we identified 6 leks that had not been previously documented. Seasonal migration patterns for individual radio-collared sage-grouse in both watersheds varied across the sites. Habitat structure metrics were similar at brood-rearing and random sites for both areas. Nesting and brood success and the ratio of chicks per successful brood were higher for both populations in 2005 than 2006. We attributed these annual differences in vital rates to seasonal variation in precipitation. Spring precipitation in 2005 was twice the 30-year average following a 5 year drought. However, chick recruitment estimates for both populations regardless of year were lower than reported in the published literature. Adult sage-grouse survival rate estimates in Sheeprock and Deep Creek watersheds were lower and higher, respectively, than published reports indicated. These differences may reflect a difference in meso-predators communities. Sage-grouse conservation strategies in both areas should continue to emphasize protection of brood-rearing and seasonal habitat, but the risk of population extirpation as a consequence of extended droughts predicted by climate change models and the invasion of small meso-predators may remain problematic for these populations.

Download

Share

COinS