A new study suggests natural gas development in western Wyoming is forcing mule deer into less suitable winter range and affecting the animals' movements in an area known as the Pinedale Anticline.
BILLINGS, Mont. A new study suggests natural gas development in western Wyoming is forcing mule deer into less suitable winter range and affecting the animals' movements in an area known as the Pinedale Anticline.
The number of mule deer on the Mesa winter range dropped a "disconcerting" 46 percent from 2002 to 2005, according to the report from Western EcoSystems Technology Inc. Models and maps indicated that, through at least three winters, deer tended to favor areas further away from well pads.
Such behavior suggests that seasonal drilling restrictions may not be achieving what land managers had intended, the researchers said.
The study includes a control population of mule deer that winter on the Pinedale Front range, near the Wind River Mountains, but researchers didn't find concurrent evidence of a population decline there. The decline on the Mesa was attributed to deaths, changes in birth and movement of deer to new wintering range, though researchers couldn't pinpoint how much each of those factors contributed.
The study, funded largely by the energy development firm Questar Exploration and Production Co., is part of an ongoing, years-long look at the potential effects of gas development on mule deer in the Green River Basin. The results were released this week by environmental groups.
Peter Aengst, an energy campaign coordinator with The Wilderness Society, said the study should serve as a wake-up call to federal land managers that changes are needed, perhaps in the pace of development or the manner in which the gas is tapped.
There are more than 400 wells on the Pinedale Anticline, and a 2000 study anticipated 2,800 wells over time. But Aengst and others say that's probably conservative.
"We can't just rely on the way we've been doing things," he said. "We have to do it differently."
Steven Hall, a spokesman for the U.S. Bureau of Land Management in Wyoming, said the agency takes studies like this into account as it makes decisions about drilling projects. He said some companies have proposed or are trying to reduce impacts during the drilling phase, when disruption to wildlife are more apt to occur.
"In order to have natural gas and oil from public lands, there will be some impact to the environment," he said, adding it's BLM's to find an appropriate balance.
A telephone message left for a Questar spokeswoman, who was out of the office Friday, was not immediately returned.
The study said restrictions, such as limiting public access, or use of different technologies, such as directional drilling, may be needed to ease the disturbance of wintering mule deer.
Environmentalists say the Mesa provides crucial winter range to thousands of mule deer and pronghorn.
Source: Associated Press