July 2007 Edition | Volume 61, Issue 7
Published since 1946
Summit and new study results add to sage-grouse deliberations
"The status quo won't do," stated Wyoming Governor David Freudenthal in regard to efforts to conserve sage-grouse in the face of energy development, reports the Wildlife Management Institute. Freudenthal's comments were made to a group of ranchers, oil and gas producers, biologists, conservationists, and state and federal officials at a summit he convened late last month. He added, "We have a narrow window of opportunity to protect the grouse and prevent it from being listed as an endangered species. My hope is that we can formulate a more unified plan that will balance protection with reasonable energy exploration, grazing and other activities that have and will continue to take place in sage grouse habitat."
Under a 2005 determination that listing sage-grouse under the federal Endangered Species Act was not warranted, the U.S. Fish and Wildlife Service (FWS) encouraged the 11 states with sage-grouse populations to develop or enhance the conservation partnerships necessary to maintain the species. Specifically, the FWS suggested that conservation efforts should focus on the most significant threats to the bird's habitat, such as invasive plants and energy development and infrastructure development (e.g., power lines, roads and fences).
Governor Freudenthal raised concern that the FWS decision was being challenged in court and that a federal endangered species listing could have an even greater impact on activities in Wyoming. The governor tasked summit participants to come up with a conservation plan that would ensure compliance by 100 percent of the oil and gas industry: "It is essential that we focus on two things. First, working with federal, state and private land interests to implement measures that have been demonstrated to positively impact sage grouse numbers and habitat. Second, we must aggressively pursue scientifically defensible estimates of the necessary habitat and sage grouse numbers to maintain the population."
Ironically, peer-reviewed research funded in part by the U.S. Bureau of Land Management, the state of Wyoming, and the oil and gas industry, and released just days after the summit concluded, appears to provide the latest in "scientifically defensible estimates." A research study in Wyoming's Powder River Basin showed that only 38 percent of sage-grouse leks existing in coal-bed natural gas (CBNG) fields in 1997 were still in existence in 2005. This was compared with 84 percent of leks outside the CBNG during that time frame. Also, from 2000 to 2005, sage-grouse populations in the CBNG declined by 86 percent (33 percent annual decline), whereas populations outside the CBNG declined by 35 percent (8 percent annual decline). In addition, active leks within the CBNG had 46 percent fewer males in 2005.
The research, conducted by University of Montana professors David Naugle and Brett Walker, confirmed that the current density of CBNG development (80- to160-acre spacing) is three to six times greater than the disturbance limit that sage-grouse can tolerate. Leks typically remain active when well spacing is greater than 500 acres. The findings also show that CBNG development is having negative effects on sage-grouse populations over and above those of habitat loss caused by wildfire, sagebrush control and conversion of sagebrush to pasture or cropland. Moreover, the extent of CBNG development explained lek inactivity better than did the impacts of power lines, pre-existing roads or West Nile virus. What isn't explained by the results, however, is where the birds have gone.
In the study, currently in press in the Journal of Wildlife Management, Naugle advised that "seasonal restrictions on drilling and construction do not address impacts caused by loss of sagebrush and incursion of infrastructure that can affect populations over long periods of time. Regulatory agencies may need to increase spatial restrictions on development, industry may need to rapidly implement more effective mitigation measures, or both, to reduce impacts of CBNG development on sage-grouse populations in the [Powder River Basin]."