Date: December 15, 2016
Source: University of Wyoming
Arid land bird populations are in decline around the vicinity of oil and gas wells in Wyoming -- but, not for the reasons you might initially think.
While such development has encroached on and hindered nesting habitat for three types of sagebrush-obligate birds, predation of these birds has increased because rodent populations in the vicinity of oil and gas wells have increased, which has, in turn, increased nest predation.
Anna Chalfoun, a University of Wyoming associate professor in the Department of Zoology and Physiology, and assistant unit leader of the Wyoming Cooperative Fish and Wildlife Unit, and her graduate students have been studying and collecting data about three species -- the Brewer's sparrow, sagebrush sparrow and sage thrasher -- in Wyoming for seven years. These birds use sagebrush for cover to build their nests on the ground or low to the ground within the sagebrush.
The study, which began seven years ago, has taken place at six sites in Jonah Field and six more at the Pinedale Anticline in western Wyoming.
"We found the majority of nest predators at the nests are rodents. Rodents are more abundant where there is natural gas development," Chalfoun says. "We tested the hypothesis that rodents were more abundant surrounding gas fields because their main predators (raptors, coyotes and badgers) avoided gas fields, but our data did not support this idea."