Wednesday, August 5, 2009 - 9:50 AM

OOS 25-6: The distribution of woodland-sagebrush avian communities in the intermountain west

Steven T. Knick and Matthias Leu. U.S. Geological Survey


Little is known about the geographical range of birds using sagebrush-woodland ecotones in the Intermountain West and the environmental gradients that influence their distributions.  We investigated avian communities in interface regions between sagebrush and Utah juniper, pinyon-pine, and western juniper at 14 sites using point counts (n = 466). 


Preliminary analyses suggest that species richness, evenness, and densities did not differ among sites.  We used NMS to determine similarity of species composition (n/ha) among sites and then related environmental gradients (location, elevation, and 19 land cover types) to community composition.  Preliminary results suggest that avian communities consisted of four species shared among all regions, six species unique to either the western juniper or the Utah juniper region, and four shared species between pinyon-pine and one of the other regions.  Sites clustered by region, except one site in Utah juniper woodlands.  Latitude, elevation, and five land cover types correlated strongly with ordination axes.  Our study is the first to document spatial changes in woodland-sagebrush avian communities across regional scales and provides important information on factors influencing the distributions of these species.