by Loretta Sorensen
Tough and hardy, this iconic western rangeplant plays an important sustainable role
Declining sage grouse populations have concerned sportsmen since the 1930s. In spite of management efforts, sage
grouse populations have continued to decline since that time. But that reality doesn’t lessen the importance of managing sage grouse and the sagebrush they’re so dependent on today. That’s why the Society for Range Management (SRM) spent much of this past year examining sage grouse and sagebrush issues. The SRM mission is to provide “leadership for the Stewardship of Rangelands based on sound ecological principles.”
“Because we serve as a primary training and education source for the grassland industry, we made these issues a major focus in 2014,” explains Jenny Pluhar, President, Society for Range Management. “We see potential for reducing the negative impact on rangeland and aiding ranchers in improving forage quality.” SRM’s efforts in 2014 have brought awareness to a number of sage grouse concerns, including the studies that indicate significant overlap between increasing free-roaming horse and burro populations and reduced sage grouse numbers in several western
states (i.e. Nevada, Wyoming, Oregon, and Utah). In addition to defining sage grouse problems over the past year, SRM has participated in discussions between managers and ranchers to identify potential solutions and direct
benefits related to sage grouse and habitat conservation.
Sagebrush dominates much of western North America, with approximately 165 million acres of potential habitat. In spite of its prevalence, sagebrush is considered a fragile ecosystem under siege from a combination of forces (i.e. invasive species, altered fire regimes, urbanization, etc.). Estimates of habitat loss vary widely depending on region, but since European settlement, at least half the area once covered by sagebrush has been eliminated.
Sagebrush grows where there is limited rain, harsh winters and trees that are restricted to streams or protected mountain slopes. Sagebrush provides important habitat for a diversity of wildlife species and domestic animals. It provides rangeland resources for cattle and sheep in areas where they coexist with other wildlife species including greater sage grouse, Brewer’s sparrow, sage thrasher, sage sparrow, common nighthawk, and pygmy rabbits. Large mammals such as mule deer, Rocky Mountain elk, moose, black bear, pronghorn, mountain lions, coyotes and gray wolves also share the broad expanse of sagebrush steppe with human inhabitants.
U.S. Department of Interior Bureau of Land Management studies have documented the dependence of sage grouse on sagebrush for nesting, brood-rearing and winter habitat. In “Guidelines to Manage Sage Grouse Populations and their Habitat,” a U.S. Geological Survey publication released in 2000, it was noted that declining sage grouse populations are correlated with a reduction in sagebrush quantity and quality over the past 50 years. Authors of the report noted that degradation of sagebrush has led to sage grouse population declines as low as 47% of historic sage grouse population counts.
It was in 1977 that Braun et al. published guidelines for sage grouse habitats that addressed topics such as seasonal
use of sagebrush habitats, effects of insecticides on sage grouse, importance of herbaceous cover in breeding habitat and the effects of fire on sagebrush habitat. As scientific knowledge of the birds has expanded over the years, that original document has been updated to reflect new findings about the birds and their habitat.
“The most recent advance in sage grouse protection has come in the form of the Sage Grouse Initiative (SGI),” Pluhar continues. “Natural Resources Conservation Service (NRCS) launched SGI in 2010, utilizing the Farm Bill as a vehicle to target lands where habitats are intact and sage grouse numbers are highest. This has brought focus to sage grouse populations on 78 million acres across 11 western states.”
SGI is a partnership of ranchers, agencies, universities, non-profit groups, and businesses working cooperatively to prevent the need for listing the sage grouse under the Endangered Species Act, which could potentially happen in 2015.
In studying the sage grouse issues, SGI has found that sage grouse, once numbering some 16 million prior to European settlement, have dwindled to as few as 200,000 birds.
“One of SGI’s primary activities has been promotion of removal of trees such as the Pinion Juniper (PJ) in areas where the trees have taken over rangeland,” Pluhar shares. “Many of those areas are places where sagebrush once thrived. The action was prompted by a study (Baruch-Mordo et al. 2013) that identified the influence of tree cover on lekking and brood-rearing habitat (lek – an area in which male animals congregate to engage in competitive displays in the hopes of gaining a female’s attention) . They found that PJ cover as low as 4% near a lek can cause birds to abandon the lekking area.
“SGI science has shown that, in Oregon alone, some 875,000 acres of trees are within three miles of leks,” Pluhar adds. “Removing trees in those lek areas greatly increases the possibility that sage grouse will return to breed and nest there.”
Over the past three years, in Oregon’s Warner Mountains, SGI and the BLM have partnered to remove nearly 50,000 acres of juniper. This tree removal has tripled the possibility for maintaining grouse populations in core habitats.
Because tree removal has additional benefits such as the return of natural springs and other wildlife species, Oregon ranchers and conservation groups have supported SGI activities.
“Tree removal is good for wildlife and productive rangeland,” Pluhar states. “Fires once kept these junipers from expanding into grasslands. However, over the past 150 years, the trees have taken over areas formerly dominated by sagebrush, grasses and forbs. Trees require a lot of water, resulting in decreased forage and loss of springs.”
SGI has also worked with ranchers to establish conservation easements, which provide sage grouse with wide open, undisturbed habitat. Strategic grazing plans are also proving to benefit the grouse. Rotating livestock to different
pastures while resting others, changing seasons of use within pastures to give plants opportunity to reproduce,
and managing frequency and intensity of grazing are all ways to support a healthy rangeland environment.
SGI researchers have also found that marking fences on rangeland to aid grouse in avoiding contact with them while in flight has significantly reduced bird loss numbers. In flat terrain, grouse are especially likely to fly into fences rather than over them. University of Idaho researcher, Bryan Stevens, developed white vinyl fence markers that snap onto the top strand of wire to make fences more visible.
Managing exotic weeds and grasses – especially cheatgrass – to help reduce fire hazards also aids grouse populations. Maintaining and supporting healthy riparian areas gives sage grouse the summer resources needed to raise hatchlings.
WHAT ABOUT THE WILD ONES?
So how do wild horses and burros fit into the sage grouse preservation story? Recent scientific research supported by the National Horse & Burro Rangeland Management Coalition has shown an overlap between areas where sage grouse are declining and wild horse and burro populations have exceeded the Appropriate Management Level (AML) set by the BLM.
Formed in 2012, the Coalition is a diverse partnership of 13 wildlife conservation and sportsmen organizations,
industry partners and professional natural-resource scientific societies. Their purpose is to identify solutions to management of free-roaming horse and burro populations.
According to 2014 Coalition documents, the number of animals in holding facilities grew from approximately
10,000 in 2001 to nearly 49,000 in 2014. Numbers on the range have increased to upwards of 40,000 in that same time period, surpassing the AML by about 13,000.
Pluhar has been actively engaged in discussions of the topic initiated by the National Horse & Burro Rangeland Management Coalition. Talks have involved SRM, the Wild Horse and Burro Advisory Board, BLM, U.S. Secretary of Agriculture and the Chief of the Forest Service. Pluhar says SRM hopes to “bring science and fact-based research to the forefront of the discussion… as a vehicle for substantial change.”
“The Society believes in the practice and enhancement of multiple use values of rangelands, while maintaining basic soil, water and vegetation resources,” Pluhar concludes.
