| The umbrella species concept is a conservation shortcut wherein multiple species are protected under the umbrella of areas protected for one species. While appealing in theory, empirical tests of the concept have been scarce. Greater Sage-Grouse (Centrocercus urophasianus, "sage-grouse") have high conservation priority across western North America, and many hope sage-grouse serve as an umbrella species, whereby conservation actions taken for sage-grouse benefit the many other at-risk wildlife species ("background species") in sagebrush ecosystems. We used a multifaceted approach (i.e., broad-scale spatial models, local empirical studies, and a controlled field experiment) in Wyoming, USA to address the following questions: Chapter 1) How much protection does a reserve established for sage-grouse offer 52 background species? Chapters 2 and 3) Do finer-scale measures of sage-grouse abundance, habitat preference, and habitat quality align with those of sagebrush-associated songbirds of concern? Chapter 4) How do mowing treatments meant to enhance sage-grouse habitat affect non-target songbirds? The reserve contained 21% of the habitat of background species on average; however, coverage varied substantially across species, with species dissimilar to sage-grouse covered least. The size of the reserve was key to its umbrella function. We found little evidence that local abundances of songbirds aligned with those of sage-grouse. Moreover, there was little concordance between sage-grouse and songbirds on which nesting habitats were preferred or associated with higher survival. Habitat treatments implemented for sage-grouse had mixed effects on songbirds, and resulted in the loss of nesting habitat for shrub-nesting species. Our results suggest that broad-scale habitat protections implemented for Greater Sage-Grouse benefited many, but not all co-occurring species of concern. Moreover, the utility of sage-grouse as an umbrella species was limited at finer spatial scales. Our findings help identify background species missed by the sage-grouse umbrella and illustrate the need to consider spatial scale in surrogate-species conservation strategies. |
