Occupied and unoccupied sage grouse habitat in Strawberry Valley, Utah

Abstract

This study evaluated multiple aspects of spring/summer sage grouse (Centrocercus urophasianus) habitat in Strawberry Valley, Utah by measuring vegetation associated with nest, brood and adult use sites. In addition, 3 types of random habitats were measured including available habitat within core use areas, random sagebrush (Artemisia spp.)/grass habitat outside core use areas, and random sagebrush/grass habitat sites that had been converted to an understory of smooth brome (Bromus inermis Leyss) by past range management practices. Logistic regression was used to identify those habitat variables that discriminated between site types. Variables that discriminated adult habitat from brood rearing habitat included: 1) sagebrush height (P ≤ 0.01) and 2) forb diversity (P = 0.12) with sagebrush height being greater at adult sites and forb diversity greater at brood sites Variables that significantly discriminated occupied adult habitat from random habitat outside of core use areas included: 1) percent grass cover (P ≤ 0.01) and 2) area of sagebrush canopy (P = 0.03) with both variables having grater values in adult habitat. Variables that significantly discriminated occupied adult habitat from random habitat with a smooth brome understory included: 1) percent forb cover (P ≤ 0.01), 2) shrub canopy cover (P = 0.02), and 3) area of sagebrush canopy (P = 0.08) with all variables being greater in adult habitat. In addition, this study identified sagebrush age, sagebrush canopy area, and forb diversity as potentially important aspects of sage grouse habitat that have not been previously reported.