Greater sage grouse needs open space to survive, thrive, says study

Posted: Apr 24, 2013

Written by

Scott Streater, Greenwire
Sage grouse

The imperiled greater sage grouse needs miles of uninterrupted sagebrush steppe with little nearby human activity to survive, according to a new federal study that also notes that land managers do not have adequate regulations in place to preserve critical areas.

The study, conducted by scientists with the U.S. Geological Survey and the University of California's Center for Conservation Biology, examined 3,000 active sage grouse breeding grounds, called leks, across a 355,000-square-mile range covering six Western states. It found that in all but a handful of cases, the active leks were located in thick sagebrush steppe and isolated from roads, development and other human activity.

The study, published this week in the journal Ecology and Evolution, could have regulatory and planning implications because it notes that large buffers are needed to protect leks and the survival of the greater sage grouse.

The Fish and Wildlife Service in 2010 designated the greater sage grouse as a candidate for listing under the Endangered Species Act. The service is under a court mandate to make a final determination by 2015 about whether to list the bird, whose habitat and populations have been declining in recent decades due to a number of factors, including habitat fragmentation and a lack of adequate regulatory mechanisms.

"We knew, from previously published science, that human activity affected sage grouse, but our results in this new research showed that most leks were even absent from areas that had very low levels of human activity," said Steve Knick, a USGS scientist with the agency's Forest and Rangeland Ecosystem Science Center in Boise, Idaho, and the lead author of the study.

The study and its conclusions take on added importance as the Bureau of Land Management develops a national sage grouse management plan that will include amending dozens of resource-management plans across the bird's 11-state range. Other states and local governments also are working to develop their own grouse-conservation plans. The study authors identify "attributes important for delineating habitats or modeling connectivity" that will help conserve and manage "landscapes important for supporting current and future sage-grouse populations," according to the study.

Indeed, the study is another important reminder that greater sage grouse are highly sensitive to disturbance from human activity, said Mark Salvo, federal lands policy analyst for Defenders of Wildlife.

"This research has important implications for current rangewide planning efforts for sage grouse," Salvo said. "We were already concerned that federal management plans released to date could permit more development than sage grouse can tolerate."

Federal, state and local leaders are desperately trying to avoid an endangered species listing for the grouse, fearing such a listing would damage the West's economy, including its vital ranching, agricultural and energy sectors.

So concerned were the leaders in Box Elder County in northwest Utah that this month they adopted a sage grouse conservation strategy that includes poisoning ravens that prey on the grouse, as well as removing pinyon and juniper and controlling noxious cheatgrass that can interfere with the grouse's sagebrush steppe habitat (Greenwire, April 11).

The USGS-led study examined a host of environmental factors within a 3-mile radius of each lek, including climate, land cover and densities of roads, power lines, pipelines and communication towers.

The researchers found that 99 percent of active leks were in landscapes with less than 3 percent of a developed category of land cover, and all lands surrounding leks were less than 14 percent developed, according to the study.

In addition, most leks were in regions characterized by broad expanses of sagebrush and contained less than 25 percent agricultural activity.

Communications towers, where predators can perch, appeared to be a major indicator of grouse activity. Active leks, according to the study, were found in areas with far less than one tower per square mile. But in areas where the towers numbered 7.1 per square mile, there were no grouse, even though grouse historically had been present in those locations.

The study also highlights the importance of preserving corridors that allow for multiple interconnected populations, noting that connected populations have a far greater chance of survival than isolated populations along the periphery of the grouse's range.

"Because conservation resources and time are limiting, delineating important areas and connecting corridors among populations could help focus actions in critical regions," according to the study.



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