Efforts to remove native trees that have expanded into sagebrush ecosystems across the Great Basin, especially juniper, are underway to restore critical habitat for wildlife, including the greater sage-grouse. It is thought that tree removal could improve survival of sagebrush-associated wildlife by reducing available habitat for predatory birds. However, the relationship between tree expansion into sagebrush habitats and predator abundance has not been scientifically evaluated. Researchers from the University of Idaho and USGS looked at the relationship between landscape characteristics, prey abundance, and habitat use by common ravens and red-tailed hawks. Surveys were conducted in the Owyhee Mountains of southwest Idaho at sites where western juniper has expanded into sagebrush habitat. The researchers found that ravens selected habitat with more juniper cover. Red-tailed hawks selected habitat near cliffs but had no relationship to juniper. These results suggest that removal of trees in similar environments could improve the survival of sage-grouse and other prey species by reducing the number of common ravens.  

Young, A.C., Katzner, T.E., Shinneman, D.J., and Johnson, T.N., 2023, Implications of tree expansion in shrubland ecosystems for two generalist avian predators: PLoS ONE, v. 18, no. 6, e0286478. https://doi.org/10.1371/journal.pone.0286478