Yale Environment Review

Yale Environment Review (YER) is a student-run review that provides weekly updates on environmental research findings.

Wildflowers and the greater sage grouse

Tom Reichner via Shutterstock

Pennington P.E., Schlaepfer D.R., Beck J.L., Bradford J.B., Palmquist K.A., Lauenroth, W.K. 2016. “Sagebrush, greater sage-grouse and the occurrence and importance of forbs.” Western North American Naturalist. 76(3), 298-312. DOI: 10.3398/064.076.0307.

Tuesday, August 29, 2017

Conservation of the greater sage grouse has been underway for a decade and continues to be a priority. Researchers describe the importance of wildflowers to the survival of this emblematic species.

The greater sage grouse, a symbolic bird of the American West, has been under careful watch by conservationists for almost a decade now. Their habitat ranges from the High Plains of Wyoming and Montana to the Pacific Coast and has decreased in size by more than 50 percent since European settlement. The sage grouse depends on acres of continuous sagebrush and wildflower habitat. Researchers are interested in how wildflowers play a role in the survival of this species.

In a recent paper, Victoria Pennington of the University of Wyoming and her colleagues conducted a first-ever literature review of the research currently available about wildflowers and their importance to the greater sage grouse. In a wide-ranging analysis of peer-reviewed papers, agency reports, conference hearings, and books, the authors outline the information available on wildflowers in sage-grouse diet and nesting site choice, as well as the extent and impact of land use and disturbance across the landscape. Their results were published in the journal Western North American Naturalist.

Current literature suggests that wildflowers make up approximately 50 percent of the sage grouse diet yet compose on average 8 percent of the landscape. They are essential for food and cover in the spring and summer months when chicks are born. As chicks grow, they follow the wave of green wildflowers across the landscape. Wildflowers also serve as an essential link between arthropods and sage grouse, because arthropods are also an important food source for young sage grouse. More arthropods were found in areas with greater wildflower abundance and diversity. Wildflowers provide a fundamental food source for the sage grouse while also providing safe nesting sites by decreasing nest visibility to predators.

Conservationists want to know how land use and disturbance such as grazing and wildfire affect sage grouse habitat. The western United States has a long history of grazing, from historical grazing by wild bison to the overgrazing now experienced in some areas primarily by domesticated livestock. Multiple studies found that these animals also like to eat wildflowers, thereby increasing competition for this highly nutritious food source. Additional studies found a decrease in the number of wildflowers with heavy livestock grazing due to an increase of non-native and invasive plants. Other disturbances like wildfires are also common for sage grouse habitat and are becoming more frequent. The authors found that wildflower recovery depends on the species and the climate pattern of the years following a fire. In general, regeneration is slow and unreliable.

Wildflowers are an aesthetic part of the Western landscape and provide food and habitat for many wildlife species living in sagebrush communities. The literature review strongly suggests that wildflowers play a key role in the life cycle of the greater sage grouse. It also suggests that future research must address wildflower diversity and abundance in greater detail while also taking into account the implications of land disturbance and climate change on sage-grouse habitat.