Mule deer populations on Wyoming's Pinedale Anticline have dropped to their lowest levels in nearly a decade, fueling concerns that intensified energy development in the natural-gas rich region has reduced the herd's crucial winter habitat.
The most recent estimates -- to be presented at a Bureau of Land Management meeting next week in Pinedale -- suggest the deer herd on the nearly 200,000-acre mesa has declined to less than half its 2001 size, dipping below agency-established thresholds that warrant "serious mitigation efforts."
"This report indicates there's a problem that hasn't been fixed," said Rollin Sparrowe, a retired biologist who worked for 22 years at the Fish and Wildlife Service. "Everybody has been told the deer situation ... is going to be bad and is getting worse."
The 19-page report, co-authored by Hall Sawyer and Ryan Nielson of Western Ecosystems Technology Inc., is the first of a handful of annual wildlife reports on the Pinedale Anticline, a windy, high-desert plain that provides vital winter forage for mule deer and pronghorn antelope.
Reports are also forthcoming on the status of prairie dogs, pygmy rabbits, raptors, elk and sage grouse that roam the anticline, which overlies what is believed to be the nation's third-largest natural gas field.
While energy development, particularly after 2008 when BLM greatly expanded drilling opportunities, is widely blamed for the mule deer declines, Sawyer cautioned that other factors could have a role. They include unusually mild winters over the past three years that may have reduced incentives for the animals to migrate and new off-highway vehicle restrictions that allowed more of the animals to remain in nearby habitat.
"It's a huge challenge to get at causation," said Sawyer, a research biologist who has studied mule deer on the anticline for the last decade. "Usually we just get correlation."
While the cause of the decline remains uncertain, the degree and rate of population decline is well-documented. According to the report, mule deer numbers on the winter range have dropped four times faster than the larger herd in Sublette County since 2005, while herd numbers on the nearby Ryegrass/Soapholes area increased over the same period.
"Following the 2008 record of decision [on drilling], the level of winter drilling activity increased on the Mesa," Sawyer wrote in the report. "It is possible that this increased winter disturbance affected fawn survival or adult reproduction."
Environmental and conservation groups have criticized BLM's decision to allow year-round drilling and the addition of 4,399 wells on 600 well pads on the anticline over the next 40 years, arguing that the new plan exchanged real habitat protections for less effective mitigation projects funded by the companies.
The Theodore Roosevelt Conservation Partnership, which has lobbied to protect the Upper Green River Basin, which includes the Pinedale area, sued BLM over the 2008 plan, claiming that the agency had failed to meet its promises to protect wildlife and ignored scientific evidence that expanded drilling was harming mule deer, sage grouse and other species (Land Letter, Oct. 15, 2009).
But the group's lawsuit was denied late last month by the U.S. District Court for the District of Columbia.
"BLM was not required ... to adopt the practices best suited to protecting wildlife," said District Judge Richard Leon, "but instead to balance the protection of wildlife with the nation's immediate and long-term need for energy resources and the lessees right to extract natural gas."
Development on the anticline is governed by a suite of adaptive management strategies that allows BLM to respond to on-the-ground conditions as oil and gas development proceeds without conducting National Environmental Policy Act reviews for each project, said John MacDonald, coordinator for BLM's Pinedale Anticline Project Office.
Mitigation can include habitat enhancements in the core drilling area, temporary suspension of surrounding leases and conservation easements outside the project area, each of which has already been implemented to some degree, MacDonald said.
BLM can also issue recommendations to gas drillers changing the pace or spatial configuration of well drilling.
"This whole venture is a cooperative process," he said. "We're not going to move forward without new input."
Emily Kelley, a spokeswoman for QEP Resources Inc., said operators on the anticline are still reviewing the report's findings and could not comment on possible mitigation steps.
"It would be premature to comment on the specific findings ahead of the BLM annual wildlife planning meeting for the Anticline on Oct. 27, when the regional director of the BLM in Wyoming will discuss the study results," she said in an e-mail.
Since September 2008, energy companies have drilled nearly 700 wells in the project area and contributed more than $5 million for mitigation, according to BLM.
Referendum on adaptive management?
Environmentalists who have tracked natural gas development on the anticline say BLM's response to the population decline could signal whether adaptive management can protect wildlife from energy development on the anticline and in other parts of the West.
Drilling in the Pinedale area boomed almost a decade ago with the advent of new technologies such as directional drilling and hydraulic fracturing that enabled companies to unlock gas trapped in tight sand formations. The area is home to an estimated 21 trillion cubic feet of natural gas, or enough to heat 12.5 million homes for 20 years.
Drilling firms -- which include QEP, Ultra Petroleum Corp. and Shell Upstream Americas -- successfully lobbied BLM to allow year-round operations in core drilling areas in its 2008 development plan for the region.
But the additional drilling authorizations came after development had already far exceeded impacts anticipated in BLM's 2000 plan, with winter ozone levels spiking due to emissions of nitrogen oxides, said the Wilderness Society's Stephanie Kessler, based in Lander, Wyo.
Kessler said it was important for energy companies to continue meeting terms of the 2008 plan calling for the construction of a liquid pipeline system to reduce truck traffic and surface infrastructure on the mesa.
An aggressive mitigation response to the mule deer findings is crucial considering the current development plan allows for thousands of additional wells to be drilled over the next decade.
"Will BLM have the political will to go to the mat?" Kessler said.
The agency's response -- and the fate of mule deer -- could also offer clues as to whether adaptive management strategies can overcome institutional and regulatory obstacles that have hindered attempts to use such approaches in the past.
"You couldn't have a better scenario of a world-class natural gas resource sitting with a world-class wildlife resource," Kessler said. "If we can't figure it out right here, there's not a lot of hope for doing it somewhere else."
Click here to read the report.